CINXE.COM
WUI Building and Fire Codes and Standards Project | NIST
<!DOCTYPE html> <html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# "> <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project","20231128043133","https://web.archive.org/","web","/_static/", "1701145893"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" /> <!-- End Wayback Rewrite JS Include --> <meta charset="utf-8"/><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["gov-bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.248.0.min.js.LICENSE.txt */ (()=>{var e,t,n={234:(e,t,n)=>{"use strict";n.d(t,{P_:()=>h,Mt:()=>m,C5:()=>s,DL:()=>w,OP:()=>j,lF:()=>R,Yu:()=>_,Dg:()=>v,CX:()=>c,GE:()=>A,sU:()=>T});var r=n(8632),i=n(9567);const a={beacon:r.ce.beacon,errorBeacon:r.ce.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},o={};function s(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!o[e])throw new Error("Info for ".concat(e," was never set"));return o[e]}function c(e,t){if(!e)throw new Error("All info objects require an agent identifier!");o[e]=(0,i.D)(t,a);const n=(0,r.ek)(e);n&&(n.info=o[e])}const u=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var d=n(7056),l=n(50);const f=()=>{const e={mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{feature_flags:[],proxy:{assets:void 0,beacon:void 0},privacy:{cookies_enabled:!0},ajax:{deny_list:void 0,block_internal:!0,enabled:!0,harvestTimeSeconds:10,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},session:{domain:void 0,expiresMs:d.oD,inactiveMs:d.Hb},ssl:void 0,obfuscate:void 0,jserrors:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},metrics:{enabled:!0,autoStart:!0},page_action:{enabled:!0,harvestTimeSeconds:30,autoStart:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,harvestTimeSeconds:30,long_task:!1,autoStart:!0},session_trace:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},harvest:{tooManyRequestsDelay:60},session_replay:{autoStart:!0,enabled:!1,harvestTimeSeconds:60,sampling_rate:50,error_sampling_rate:50,collect_fonts:!1,inline_images:!1,inline_stylesheet:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){u(t)?e.mask_selector=t+",[data-nr-mask]":null===t?e.mask_selector=t:(0,l.Z)("An invalid session_replay.mask_selector was provided and will not be used",t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){u(t)?e.block_selector+=",".concat(t):""!==t&&(0,l.Z)("An invalid session_replay.block_selector was provided and will not be used",t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,l.Z)("An invalid session_replay.mask_input_option was provided and will not be used",t)}},spa:{enabled:!0,harvestTimeSeconds:10,autoStart:!0}}},g={},p="All configuration objects require an agent identifier!";function h(e){if(!e)throw new Error(p);if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function v(e,t){if(!e)throw new Error(p);g[e]=(0,i.D)(t,f());const n=(0,r.ek)(e);n&&(n.init=g[e])}function m(e,t){if(!e)throw new Error(p);var n=h(e);if(n){for(var r=t.split("."),i=0;i<r.length-1;i++)if("object"!=typeof(n=n[r[i]]))return;n=n[r[r.length-1]]}return n}const b={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},y={};function w(e){if(!e)throw new Error("All loader-config objects require an agent identifier!");if(!y[e])throw new Error("LoaderConfig for ".concat(e," was never set"));return y[e]}function A(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");y[e]=(0,i.D)(t,b);const n=(0,r.ek)(e);n&&(n.loader_config=y[e])}const _=(0,r.mF)().o;var x=n(385),D=n(6818);const k={buildEnv:D.Re,customTransaction:void 0,disabled:!1,distMethod:D.gF,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,offset:Math.floor(x._A?.performance?.timeOrigin||x._A?.performance?.timing?.navigationStart||Date.now()),onerror:void 0,origin:""+x._A.location,ptid:void 0,releaseIds:{},session:void 0,xhrWrappable:"function"==typeof x._A.XMLHttpRequest?.prototype?.addEventListener,version:D.q4,denyList:void 0},E={};function j(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!E[e])throw new Error("Runtime for ".concat(e," was never set"));return E[e]}function T(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");E[e]=(0,i.D)(t,k);const n=(0,r.ek)(e);n&&(n.runtime=E[e])}function R(e){return function(e){try{const t=s(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}(e)}},9567:(e,t,n)=>{"use strict";n.d(t,{D:()=>i});var r=n(50);function i(e,t){try{if(!e||"object"!=typeof e)return(0,r.Z)("Setting a Configurable requires an object as input");if(!t||"object"!=typeof t)return(0,r.Z)("Setting a Configurable requires a model to set its initial properties");const n=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),a=0===Object.keys(n).length?e:n;for(let o in a)if(void 0!==e[o])try{Array.isArray(e[o])&&Array.isArray(t[o])?n[o]=Array.from(new Set([...e[o],...t[o]])):"object"==typeof e[o]&&"object"==typeof t[o]?n[o]=i(e[o],t[o]):n[o]=e[o]}catch(e){(0,r.Z)("An error occurred while setting a property of a Configurable",e)}return n}catch(e){(0,r.Z)("An error occured while setting a Configurable",e)}}},6818:(e,t,n)=>{"use strict";n.d(t,{Re:()=>i,gF:()=>a,q4:()=>r});const r="1.248.0",i="PROD",a="CDN"},385:(e,t,n)=>{"use strict";n.d(t,{Nk:()=>d,Tt:()=>s,_A:()=>a,cv:()=>l,iS:()=>o,il:()=>r,ux:()=>c,v6:()=>i,w1:()=>u});const r="undefined"!=typeof window&&!!window.document,i="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=r?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),o=(a?.document?.readyState,Boolean("hidden"===a?.document?.visibilityState)),s=(a?.location,/iPad|iPhone|iPod/.test(a.navigator?.userAgent)),c=s&&"undefined"==typeof SharedWorker,u=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Boolean(r&&window.document.documentMode)),d=!!a.navigator?.sendBeacon,l=Math.floor(a?.performance?.timeOrigin||a?.performance?.timing?.navigationStart||Date.now())},1117:(e,t,n)=>{"use strict";n.d(t,{w:()=>a});var r=n(50);const i={agentIdentifier:"",ee:void 0};class a{constructor(e){try{if("object"!=typeof e)return(0,r.Z)("shared context requires an object as input");this.sharedContext={},Object.assign(this.sharedContext,i),Object.entries(e).forEach((e=>{let[t,n]=e;Object.keys(i).includes(t)&&(this.sharedContext[t]=n)}))}catch(e){(0,r.Z)("An error occured while setting SharedContext",e)}}}},8e3:(e,t,n)=>{"use strict";n.d(t,{L:()=>d,R:()=>c});var r=n(8325),i=n(1284),a=n(4322),o=n(3325);const s={};function c(e,t){const n={staged:!1,priority:o.p[t]||0};u(e),s[e].get(t)||s[e].set(t,n)}function u(e){e&&(s[e]||(s[e]=new Map))}function d(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:"",t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:"feature";if(u(e),!e||!s[e].get(t))return o(t);s[e].get(t).staged=!0;const n=[...s[e]];function o(t){const n=e?r.ee.get(e):r.ee,o=a.X.handlers;if(n.backlog&&o){var s=n.backlog[t],c=o[t];if(c){for(var u=0;s&&u<s.length;++u)l(s[u],c);(0,i.D)(c,(function(e,t){(0,i.D)(t,(function(t,n){n[0].on(e,n[1])}))}))}delete o[t],n.backlog[t]=null,n.emit("drain-"+t,[])}}n.every((e=>{let[t,n]=e;return n.staged}))&&(n.sort(((e,t)=>e[1].priority-t[1].priority)),n.forEach((t=>{let[n]=t;s[e].delete(n),o(n)})))}function l(e,t){var n=e[1];(0,i.D)(t[n],(function(t,n){var r=e[0];if(n[0]===r){var i=n[1],a=e[3],o=e[2];i.apply(a,o)}}))}},8325:(e,t,n)=>{"use strict";n.d(t,{A:()=>c,ee:()=>u});var r=n(8632),i=n(2210),a=n(234);class o{constructor(e){this.contextId=e}}var s=n(3117);const c="nr@context:".concat(s.a),u=function e(t,n){var r={},s={},d={},f=!1;try{f=16===n.length&&(0,a.OP)(n).isolatedBacklog}catch(e){}var g={on:h,addEventListener:h,removeEventListener:function(e,t){var n=r[e];if(!n)return;for(var i=0;i<n.length;i++)n[i]===t&&n.splice(i,1)},emit:function(e,n,r,i,a){!1!==a&&(a=!0);if(u.aborted&&!i)return;t&&a&&t.emit(e,n,r);for(var o=p(r),c=v(e),d=c.length,l=0;l<d;l++)c[l].apply(o,n);var f=b()[s[e]];f&&f.push([g,e,n,o]);return o},get:m,listeners:v,context:p,buffer:function(e,t){const n=b();if(t=t||"feature",g.aborted)return;Object.entries(e||{}).forEach((e=>{let[r,i]=e;s[i]=t,t in n||(n[t]=[])}))},abort:l,aborted:!1,isBuffering:function(e){return!!b()[s[e]]},debugId:n,backlog:f?{}:t&&"object"==typeof t.backlog?t.backlog:{}};return g;function p(e){return e&&e instanceof o?e:e?(0,i.X)(e,c,(()=>new o(c))):new o(c)}function h(e,t){r[e]=v(e).concat(t)}function v(e){return r[e]||[]}function m(t){return d[t]=d[t]||e(g,t)}function b(){return g.backlog}}(void 0,"globalEE"),d=(0,r.fP)();function l(){u.aborted=!0,u.backlog={}}d.ee||(d.ee=u)},5546:(e,t,n)=>{"use strict";n.d(t,{E:()=>r,p:()=>i});var r=n(8325).ee.get("handle");function i(e,t,n,i,a){a?(a.buffer([e],i),a.emit(e,t,n)):(r.buffer([e],i),r.emit(e,t,n))}},4322:(e,t,n)=>{"use strict";n.d(t,{X:()=>a});var r=n(5546);a.on=o;var i=a.handlers={};function a(e,t,n,a){o(a||r.E,i,e,t,n)}function o(e,t,n,i,a){a||(a="feature"),e||(e=r.E);var o=t[a]=t[a]||{};(o[n]=o[n]||[]).push([e,i])}},3239:(e,t,n)=>{"use strict";n.d(t,{bP:()=>s,iz:()=>c,m$:()=>o});var r=n(385);let i=!1,a=!1;try{const e={get passive(){return i=!0,!1},get signal(){return a=!0,!1}};r._A.addEventListener("test",null,e),r._A.removeEventListener("test",null,e)}catch(e){}function o(e,t){return i||a?{capture:!!e,passive:i,signal:t}:!!e}function s(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2],r=arguments.length>3?arguments[3]:void 0;window.addEventListener(e,t,o(n,r))}function c(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2],r=arguments.length>3?arguments[3]:void 0;document.addEventListener(e,t,o(n,r))}},3117:(e,t,n)=>{"use strict";n.d(t,{a:()=>r});const r=(0,n(4402).Rl)()},4402:(e,t,n)=>{"use strict";n.d(t,{Rl:()=>o,ky:()=>s});var r=n(385);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function a(e,t){return e?15&e[t]:16*Math.random()|0}function o(){const e=r._A?.crypto||r._A?.msCrypto;let t,n=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(31))),i.split("").map((e=>"x"===e?a(t,++n).toString(16):"y"===e?(3&a()|8).toString(16):e)).join("")}function s(e){const t=r._A?.crypto||r._A?.msCrypto;let n,i=0;t&&t.getRandomValues&&(n=t.getRandomValues(new Uint8Array(31)));const o=[];for(var s=0;s<e;s++)o.push(a(n,++i).toString(16));return o.join("")}},7056:(e,t,n)=>{"use strict";n.d(t,{Bq:()=>r,Hb:()=>a,oD:()=>i});const r="NRBA",i=144e5,a=18e5},7894:(e,t,n)=>{"use strict";function r(){return Math.round(performance.now())}n.d(t,{z:()=>r})},50:(e,t,n)=>{"use strict";function r(e,t){"function"==typeof console.warn&&(console.warn("New Relic: ".concat(e)),t&&console.warn(t))}n.d(t,{Z:()=>r})},2825:(e,t,n)=>{"use strict";n.d(t,{N:()=>d,T:()=>l});var r=n(8325),i=n(5546),a=n(3325),o=n(385);const s="newrelic";const c={stn:[a.D.sessionTrace],err:[a.D.jserrors,a.D.metrics],ins:[a.D.pageAction],spa:[a.D.spa],sr:[a.D.sessionReplay,a.D.sessionTrace]},u=new Set;function d(e,t){const n=r.ee.get(t);e&&"object"==typeof e&&(u.has(t)||(Object.entries(e).forEach((e=>{let[t,r]=e;c[t]?c[t].forEach((e=>{r?(0,i.p)("feat-"+t,[],void 0,e,n):(0,i.p)("block-"+t,[],void 0,e,n),(0,i.p)("rumresp-"+t,[Boolean(r)],void 0,e,n)})):r&&(0,i.p)("feat-"+t,[],void 0,void 0,n),l[t]=Boolean(r)})),Object.keys(c).forEach((e=>{void 0===l[e]&&(c[e]?.forEach((t=>(0,i.p)("rumresp-"+e,[!1],void 0,t,n))),l[e]=!1)})),u.add(t),function(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};try{o._A.dispatchEvent(new CustomEvent(s,{detail:e}))}catch(e){}}({loaded:!0})))}const l={}},2210:(e,t,n)=>{"use strict";n.d(t,{X:()=>i});var r=Object.prototype.hasOwnProperty;function i(e,t,n){if(r.call(e,t))return e[t];var i=n();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},1284:(e,t,n)=>{"use strict";n.d(t,{D:()=>r});const r=(e,t)=>Object.entries(e||{}).map((e=>{let[n,r]=e;return t(n,r)}))},4351:(e,t,n)=>{"use strict";n.d(t,{P:()=>a});var r=n(8325);const i=()=>{const e=new WeakSet;return(t,n)=>{if("object"==typeof n&&null!==n){if(e.has(n))return;e.add(n)}return n}};function a(e){try{return JSON.stringify(e,i())}catch(e){try{r.ee.emit("internal-error",[e])}catch(e){}}}},3960:(e,t,n)=>{"use strict";n.d(t,{KB:()=>o,b2:()=>a});var r=n(3239);function i(){return"undefined"==typeof document||"complete"===document.readyState}function a(e,t){if(i())return e();(0,r.bP)("load",e,t)}function o(e){if(i())return e();(0,r.iz)("DOMContentLoaded",e)}},8632:(e,t,n)=>{"use strict";n.d(t,{EZ:()=>d,ce:()=>a,ek:()=>u,fP:()=>o,gG:()=>l,h5:()=>c,mF:()=>s});var r=n(7894),i=n(385);const a={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function o(){return i._A.NREUM||(i._A.NREUM={}),void 0===i._A.newrelic&&(i._A.newrelic=i._A.NREUM),i._A.NREUM}function s(){let e=o();return e.o||(e.o={ST:i._A.setTimeout,SI:i._A.setImmediate,CT:i._A.clearTimeout,XHR:i._A.XMLHttpRequest,REQ:i._A.Request,EV:i._A.Event,PR:i._A.Promise,MO:i._A.MutationObserver,FETCH:i._A.fetch}),e}function c(e,t){let n=o();n.initializedAgents??={},t.initializedAt={ms:(0,r.z)(),date:new Date},n.initializedAgents[e]=t}function u(e){let t=o();return t.initializedAgents?.[e]}function d(e,t){o()[e]=t}function l(){return function(){let e=o();const t=e.info||{};e.info={beacon:a.beacon,errorBeacon:a.errorBeacon,...t}}(),function(){let e=o();const t=e.init||{};e.init={...t}}(),s(),function(){let e=o();const t=e.loader_config||{};e.loader_config={...t}}(),o()}},7956:(e,t,n)=>{"use strict";n.d(t,{N:()=>i});var r=n(3239);function i(e){let t=arguments.length>1&&void 0!==arguments[1]&&arguments[1],n=arguments.length>2?arguments[2]:void 0,i=arguments.length>3?arguments[3]:void 0;(0,r.iz)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),n,i)}},3081:(e,t,n)=>{"use strict";n.d(t,{gF:()=>a,mY:()=>i,t9:()=>r,vz:()=>s,xS:()=>o});const r=n(3325).D.metrics,i="sm",a="cm",o="storeSupportabilityMetrics",s="storeEventMetrics"},7633:(e,t,n)=>{"use strict";n.d(t,{t:()=>r});const r=n(3325).D.pageViewEvent},9251:(e,t,n)=>{"use strict";n.d(t,{t:()=>r});const r=n(3325).D.pageViewTiming},5938:(e,t,n)=>{"use strict";n.d(t,{W:()=>i});var r=n(8325);class i{constructor(e,t,n){this.agentIdentifier=e,this.aggregator=t,this.ee=r.ee.get(e),this.featureName=n,this.blocked=!1}}},7530:(e,t,n)=>{"use strict";n.d(t,{j:()=>b});var r=n(3325),i=n(234),a=n(5546),o=n(8325),s=n(7894),c=n(8e3),u=n(3960),d=n(385),l=n(50),f=n(3081),g=n(8632);function p(){const e=(0,g.gG)();["setErrorHandler","finished","addToTrace","addRelease","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start","recordReplay","pauseReplay"].forEach((t=>{e[t]=function(){for(var n=arguments.length,r=new Array(n),i=0;i<n;i++)r[i]=arguments[i];return function(t){for(var n=arguments.length,r=new Array(n>1?n-1:0),i=1;i<n;i++)r[i-1]=arguments[i];let a=[];return Object.values(e.initializedAgents).forEach((e=>{e.exposed&&e.api[t]&&a.push(e.api[t](...r))})),a.length>1?a:a[0]}(t,...r)}}))}var h=n(2825);const v=e=>{const t=e.startsWith("http");e+="/",n.p=t?e:"https://"+e};let m=!1;function b(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:{},b=arguments.length>2?arguments[2]:void 0,y=arguments.length>3?arguments[3]:void 0,{init:w,info:A,loader_config:_,runtime:x={loaderType:b},exposed:D=!0}=t;const k=(0,g.gG)();A||(w=k.init,A=k.info,_=k.loader_config),(0,i.Dg)(e.agentIdentifier,w||{}),(0,i.GE)(e.agentIdentifier,_||{}),A.jsAttributes??={},d.v6&&(A.jsAttributes.isWorker=!0),(0,i.CX)(e.agentIdentifier,A);const E=(0,i.P_)(e.agentIdentifier),j=[A.beacon,A.errorBeacon];m||(E.proxy.assets&&(v(E.proxy.assets),j.push(E.proxy.assets)),E.proxy.beacon&&j.push(E.proxy.beacon),p(),(0,g.EZ)("activatedFeatures",h.T)),x.denyList=[...E.ajax.deny_list||[],...E.ajax.block_internal?j:[]],(0,i.sU)(e.agentIdentifier,x),void 0===e.api&&(e.api=function(e,t){t||(0,c.R)(e,"api");const g={};var p=o.ee.get(e),h=p.get("tracer"),v="api-",m=v+"ixn-";function b(t,n,r,a){const o=(0,i.C5)(e);return null===n?delete o.jsAttributes[t]:(0,i.CX)(e,{...o,jsAttributes:{...o.jsAttributes,[t]:n}}),A(v,r,!0,a||null===n?"session":void 0)(t,n)}function y(){}["setErrorHandler","finished","addToTrace","addRelease"].forEach((e=>{g[e]=A(v,e,!0,"api")})),g.addPageAction=A(v,"addPageAction",!0,r.D.pageAction),g.setCurrentRouteName=A(v,"routeName",!0,r.D.spa),g.setPageViewName=function(t,n){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,i.OP)(e).customTransaction=(n||"https://web.archive.org/web/20231128043133/http://custom.transaction")+t,A(v,"setPageViewName",!0)()},g.setCustomAttribute=function(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2];if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return b(e,t,"setCustomAttribute",n);(0,l.Z)("Failed to execute setCustomAttribute.\nNon-null value must be a string, number or boolean type, but a type of <".concat(typeof t,"> was provided."))}else(0,l.Z)("Failed to execute setCustomAttribute.\nName must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setUserId=function(e){if("string"==typeof e||null===e)return b("enduser.id",e,"setUserId",!0);(0,l.Z)("Failed to execute setUserId.\nNon-null value must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setApplicationVersion=function(e){if("string"==typeof e||null===e)return b("application.version",e,"setApplicationVersion",!1);(0,l.Z)("Failed to execute setApplicationVersion. Expected <String | null>, but got <".concat(typeof e,">."))},g.start=e=>{try{const t=e?"defined":"undefined";(0,a.p)(f.xS,["API/start/".concat(t,"/called")],void 0,r.D.metrics,p);const n=Object.values(r.D);if(void 0===e)e=n;else{if((e=Array.isArray(e)&&e.length?e:[e]).some((e=>!n.includes(e))))return(0,l.Z)("Invalid feature name supplied. Acceptable feature names are: ".concat(n));e.includes(r.D.pageViewEvent)||e.push(r.D.pageViewEvent)}e.forEach((e=>{p.emit("".concat(e,"-opt-in"))}))}catch(e){(0,l.Z)("An unexpected issue occurred",e)}},g.recordReplay=function(){(0,a.p)(f.xS,["API/recordReplay/called"],void 0,r.D.metrics,p),(0,a.p)("recordReplay",[],void 0,r.D.sessionReplay,p)},g.pauseReplay=function(){(0,a.p)(f.xS,["API/pauseReplay/called"],void 0,r.D.metrics,p),(0,a.p)("pauseReplay",[],void 0,r.D.sessionReplay,p)},g.interaction=function(){return(new y).get()};var w=y.prototype={createTracer:function(e,t){var n={},i=this,o="function"==typeof t;return(0,a.p)(f.xS,["API/createTracer/called"],void 0,r.D.metrics,p),(0,a.p)(m+"tracer",[(0,s.z)(),e,n],i,r.D.spa,p),function(){if(h.emit((o?"":"no-")+"fn-start",[(0,s.z)(),i,o],n),o)try{return t.apply(this,arguments)}catch(e){throw h.emit("fn-err",[arguments,this,e],n),e}finally{h.emit("fn-end",[(0,s.z)()],n)}}}};function A(e,t,n,i){return function(){return(0,a.p)(f.xS,["API/"+t+"/called"],void 0,r.D.metrics,p),i&&(0,a.p)(e+t,[(0,s.z)(),...arguments],n?null:this,i,p),n?void 0:this}}function _(){n.e(75).then(n.bind(n,7438)).then((t=>{let{setAPI:n}=t;n(e),(0,c.L)(e,"api")})).catch((()=>(0,l.Z)("Downloading runtime APIs failed...")))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{w[e]=A(m,e,void 0,r.D.spa)})),g.noticeError=function(e,t){"string"==typeof e&&(e=new Error(e)),(0,a.p)(f.xS,["API/noticeError/called"],void 0,r.D.metrics,p),(0,a.p)("err",[e,(0,s.z)(),!1,t],void 0,r.D.jserrors,p)},d.il?(0,u.b2)((()=>_()),!0):_(),g}(e.agentIdentifier,y)),void 0===e.exposed&&(e.exposed=D),m=!0}},1926:(e,t,n)=>{n.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},3325:(e,t,n)=>{"use strict";n.d(t,{D:()=>r,p:()=>i});const r={ajax:"ajax",jserrors:"jserrors",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",spa:"spa"},i={[r.pageViewEvent]:1,[r.pageViewTiming]:2,[r.metrics]:3,[r.jserrors]:4,[r.ajax]:5,[r.sessionTrace]:6,[r.pageAction]:7,[r.spa]:8,[r.sessionReplay]:9}}},r={};function i(e){var t=r[e];if(void 0!==t)return t.exports;var a=r[e]={exports:{}};return n[e](a,a.exports,i),a.exports}i.m=n,i.d=(e,t)=>{for(var n in t)i.o(t,n)&&!i.o(e,n)&&Object.defineProperty(e,n,{enumerable:!0,get:t[n]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,n)=>(i.f[n](e,t),t)),[])),i.u=e=>"nr-rum-1.248.0.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.248.0.PROD:",i.l=(n,r,a,o)=>{if(e[n])e[n].push(r);else{var s,c;if(void 0!==a)for(var u=document.getElementsByTagName("script"),d=0;d<u.length;d++){var l=u[d];if(l.getAttribute("src")==n||l.getAttribute("data-webpack")==t+a){s=l;break}}s||(c=!0,(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+a),s.src=n,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),s.integrity=i.sriHashes[o],s.crossOrigin="anonymous"),e[n]=[r];var f=(t,r)=>{s.onerror=s.onload=null,clearTimeout(g);var i=e[n];if(delete e[n],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(r))),t)return t(r)},g=setTimeout(f.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=f.bind(null,s.onerror),s.onload=f.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://web.archive.org/web/20231128043133/https://js-agent.newrelic.com/",i.sriHashes={75:"sha512-5mWtMwj7hrXT5aUkfvBtjH6FJXsR+zdeMBfc721nzrOx36xa23yTrCB1VVOAQa+zIioAbWPW4m7UsPp7hW1WPw=="},(()=>{var e={50:0,832:0};i.f.j=(t,n)=>{var r=i.o(e,t)?e[t]:void 0;if(0!==r)if(r)n.push(r[2]);else{var a=new Promise(((n,i)=>r=e[t]=[n,i]));n.push(r[2]=a);var o=i.p+i.u(t),s=new Error;i.l(o,(n=>{if(i.o(e,t)&&(0!==(r=e[t])&&(e[t]=void 0),r)){var a=n&&("load"===n.type?"missing":n.type),o=n&&n.target&&n.target.src;s.message="Loading chunk "+t+" failed.\n("+a+": "+o+")",s.name="ChunkLoadError",s.type=a,s.request=o,r[1](s)}}),"chunk-"+t,t)}};var t=(t,n)=>{var r,a,[o,s,c]=n,u=0;if(o.some((t=>0!==e[t]))){for(r in s)i.o(s,r)&&(i.m[r]=s[r]);if(c)c(i)}for(t&&t(n);u<o.length;u++)a=o[u],i.o(e,a)&&e[a]&&e[a][0](),e[a]=0},n=self["webpackChunk:NRBA-1.248.0.PROD"]=self["webpackChunk:NRBA-1.248.0.PROD"]||[];n.forEach(t.bind(null,0)),n.push=t.bind(null,n.push.bind(n))})(),(()=>{"use strict";i(1926);var e=i(50);class t{addPageAction(t,n){(0,e.Z)("Call to agent api addPageAction failed. The page action feature is not currently initialized.")}setPageViewName(t,n){(0,e.Z)("Call to agent api setPageViewName failed. The page view feature is not currently initialized.")}setCustomAttribute(t,n,r){(0,e.Z)("Call to agent api setCustomAttribute failed. The js errors feature is not currently initialized.")}noticeError(t,n){(0,e.Z)("Call to agent api noticeError failed. The js errors feature is not currently initialized.")}setUserId(t){(0,e.Z)("Call to agent api setUserId failed. The js errors feature is not currently initialized.")}setApplicationVersion(t){(0,e.Z)("Call to agent api setApplicationVersion failed. The agent is not currently initialized.")}setErrorHandler(t){(0,e.Z)("Call to agent api setErrorHandler failed. The js errors feature is not currently initialized.")}finished(t){(0,e.Z)("Call to agent api finished failed. The page action feature is not currently initialized.")}addRelease(t,n){(0,e.Z)("Call to agent api addRelease failed. The js errors feature is not currently initialized.")}start(t){(0,e.Z)("Call to agent api addRelease failed. The agent is not currently initialized.")}recordReplay(){(0,e.Z)("Call to agent api recordReplay failed. The agent is not currently initialized.")}pauseReplay(){(0,e.Z)("Call to agent api pauseReplay failed. The agent is not currently initialized.")}}var n=i(3325),r=i(234);const a=Object.values(n.D);function o(e){const t={};return a.forEach((n=>{t[n]=function(e,t){return!1!==(0,r.Mt)(t,"".concat(e,".enabled"))}(n,e)})),t}var s=i(7530);var c=i(8e3),u=i(5938),d=i(3960),l=i(385);class f extends u.W{constructor(e,t,n){let i=!(arguments.length>3&&void 0!==arguments[3])||arguments[3];super(e,t,n),this.auto=i,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===(0,r.Mt)(this.agentIdentifier,"".concat(this.featureName,".autoStart"))&&(this.auto=!1),this.auto&&(0,c.R)(e,n)}importAggregator(){let t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};if(this.featAggregate)return;if(!this.auto)return void this.ee.on("".concat(this.featureName,"-opt-in"),(()=>{(0,c.R)(this.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator()}));const n=l.il&&!0===(0,r.Mt)(this.agentIdentifier,"privacy.cookies_enabled");let a;this.onAggregateImported=new Promise((e=>{a=e}));const o=async()=>{let r;try{if(n){const{setupAgentSession:e}=await i.e(75).then(i.bind(i,3228));r=e(this.agentIdentifier)}}catch(t){(0,e.Z)("A problem occurred when starting up session manager. This page will not start or extend any session.",t)}try{if(!this.shouldImportAgg(this.featureName,r))return(0,c.L)(this.agentIdentifier,this.featureName),void a(!1);const{lazyFeatureLoader:e}=await i.e(75).then(i.bind(i,8582)),{Aggregate:n}=await e(this.featureName,"aggregate");this.featAggregate=new n(this.agentIdentifier,this.aggregator,t),a(!0)}catch(t){(0,e.Z)("Downloading and initializing ".concat(this.featureName," failed..."),t),this.abortHandler?.(),(0,c.L)(this.agentIdentifier,this.featureName),a(!1)}};l.il?(0,d.b2)((()=>o()),!0):o()}shouldImportAgg(e,t){return e!==n.D.sessionReplay||!!r.Yu.MO&&(!1!==(0,r.Mt)(this.agentIdentifier,"session_trace.enabled")&&(!!t?.isNew||!!t?.state.sessionReplayMode))}}var g=i(7633);class p extends f{static featureName=g.t;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,g.t,n),this.importAggregator()}}var h=i(1117),v=i(1284);class m extends h.w{constructor(e){super(e),this.aggregatedData={}}store(e,t,n,r,i){var a=this.getBucket(e,t,n,i);return a.metrics=function(e,t){t||(t={count:0});return t.count+=1,(0,v.D)(e,(function(e,n){t[e]=b(n,t[e])})),t}(r,a.metrics),a}merge(e,t,n,r,i){var a=this.getBucket(e,t,r,i);if(a.metrics){var o=a.metrics;o.count+=n.count,(0,v.D)(n,(function(e,t){if("count"!==e){var r=o[e],i=n[e];i&&!i.c?o[e]=b(i.t,r):o[e]=function(e,t){if(!t)return e;t.c||(t=y(t.t));return t.min=Math.min(e.min,t.min),t.max=Math.max(e.max,t.max),t.t+=e.t,t.sos+=e.sos,t.c+=e.c,t}(i,o[e])}}))}else a.metrics=n}storeMetric(e,t,n,r){var i=this.getBucket(e,t,n);return i.stats=b(r,i.stats),i}getBucket(e,t,n,r){this.aggregatedData[e]||(this.aggregatedData[e]={});var i=this.aggregatedData[e][t];return i||(i=this.aggregatedData[e][t]={params:n||{}},r&&(i.custom=r)),i}get(e,t){return t?this.aggregatedData[e]&&this.aggregatedData[e][t]:this.aggregatedData[e]}take(e){for(var t={},n="",r=!1,i=0;i<e.length;i++)t[n=e[i]]=w(this.aggregatedData[n]),t[n].length&&(r=!0),delete this.aggregatedData[n];return r?t:null}}function b(e,t){return null==e?function(e){e?e.c++:e={c:1};return e}(t):t?(t.c||(t=y(t.t)),t.c+=1,t.t+=e,t.sos+=e*e,e>t.max&&(t.max=e),e<t.min&&(t.min=e),t):{t:e}}function y(e){return{t:e,min:e,max:e,sos:e*e,c:1}}function w(e){return"object"!=typeof e?[]:(0,v.D)(e,A)}function A(e,t){return t}var _=i(8632),x=i(4402),D=i(4351);var k=i(5546),E=i(7956),j=i(3239),T=i(7894),R=i(9251);class S extends f{static featureName=R.t;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,R.t,n),l.il&&((0,E.N)((()=>(0,k.p)("docHidden",[(0,T.z)()],void 0,R.t,this.ee)),!0),(0,j.bP)("pagehide",(()=>(0,k.p)("winPagehide",[(0,T.z)()],void 0,R.t,this.ee))),this.importAggregator())}}var I=i(3081);class C extends f{static featureName=I.t9;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,I.t9,n),this.importAggregator()}}new class extends t{constructor(t){let n=arguments.length>1&&void 0!==arguments[1]?arguments[1]:(0,x.ky)(16);super(),l._A?(this.agentIdentifier=n,this.sharedAggregator=new m({agentIdentifier:this.agentIdentifier}),this.features={},(0,_.h5)(n,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(p),(0,s.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.Z)("Failed to initial the agent. Could not determine the runtime environment.")}get config(){return{info:(0,r.C5)(this.agentIdentifier),init:(0,r.P_)(this.agentIdentifier),loader_config:(0,r.DL)(this.agentIdentifier),runtime:(0,r.OP)(this.agentIdentifier)}}run(){try{const t=o(this.agentIdentifier),r=[...this.desiredFeatures];r.sort(((e,t)=>n.p[e.featureName]-n.p[t.featureName])),r.forEach((r=>{if(t[r.featureName]||r.featureName===n.D.pageViewEvent){const i=function(e){switch(e){case n.D.ajax:return[n.D.jserrors];case n.D.sessionTrace:return[n.D.ajax,n.D.pageViewEvent];case n.D.sessionReplay:return[n.D.sessionTrace];case n.D.pageViewTiming:return[n.D.pageViewEvent];default:return[]}}(r.featureName);i.every((e=>t[e]))||(0,e.Z)("".concat(r.featureName," is enabled but one or more dependent features has been disabled (").concat((0,D.P)(i),"). This may cause unintended consequences or missing data...")),this.features[r.featureName]=new r(this.agentIdentifier,this.sharedAggregator)}}))}catch(t){(0,e.Z)("Failed to initialize all enabled instrument classes (agent aborted) -",t);for(const e in this.features)this.features[e].abortHandler?.();const n=(0,_.fP)();return delete n.initializedAgents[this.agentIdentifier]?.api,delete n.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator,n.ee?.abort(),delete n.ee?.get(this.agentIdentifier),!1}}addToTrace(t){(0,e.Z)("Call to agent api addToTrace failed. The session trace feature is not currently initialized.")}setCurrentRouteName(t){(0,e.Z)("Call to agent api setCurrentRouteName failed. The spa feature is not currently initialized.")}interaction(){(0,e.Z)("Call to agent api interaction failed. The spa feature is not currently initialized.")}}({features:[p,S,C],loaderType:"lite"})})()})();</script> <noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style> </noscript><script async src="https://web.archive.org/web/20231128043133js_/https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script> <script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("event", "custom", {"node_title":"WUI Building and Fire Codes and Standards Project","node_id":"418101","content_type":"Project\/Program"});</script> <meta name="description" content="Although over 46 million residential structures in the United States are in areas of risk of wildfires, building and fire codes and standards do not provide the same resiliency for structures in wildland-urban interface (WUI) communities as provided in urban communities. Projects within the Fire Ris"/> <link rel="canonical" href="https://web.archive.org/web/20231128043133/https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project"/> <link rel="shortlink" href="https://web.archive.org/web/20231128043133/https://www.nist.gov/node/418101"/> <meta name="citation_title" content="WUI Building and Fire Codes and Standards Project | NIST"/> <meta property="og:site_name" content="NIST"/> <meta property="og:type" content="Article"/> <meta property="og:url" content="https://web.archive.org/web/20231128043133/https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project"/> <meta property="og:title" content="WUI Building and Fire Codes and Standards Project"/> <meta property="og:description" content="Although over 46 million residential structures in the United States are in areas of risk of wildfires, building and fire codes and standards do not provide the same resiliency for structures in wildland-urban interface (WUI) communities as provided in urban communities. Projects within the Fire Ris"/> <meta property="article:modified_time" content="2017-07-19T11:45-04:00"/> <meta name="dcterms.title" content="WUI Building and Fire Codes and Standards Project"/> <meta name="dcterms.description" content="Although over 46 million residential structures in the United States are in areas of risk of wildfires, building and fire codes and standards do not provide the same resiliency for structures in wildland-urban interface (WUI) communities as provided in urban communities. Projects within the Fire Ris"/> <meta name="dcterms.type" content="text"/> <meta name="dcterms.format" content="text/html"/> <meta name="dcterms.identifier" content="https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project"/> <meta name="dcterms.source" content="NIST"/> <meta name="dcterms.modified" content="2017-07-19T11:45-04:00"/> <meta name="twitter:card" content="summary_large_image"/> <meta name="twitter:description" content="Although over 46 million residential structures in the United States are in areas of risk of wildfires, building and fire codes and standards do not provide the same resiliency for structures in wildland-urban interface (WUI) communities as provided in urban communities. Projects within the Fire Ris"/> <meta name="twitter:site" content="NIST"/> <meta name="twitter:title" content="WUI Building and Fire Codes and Standards Project"/> <meta name="twitter:url" content="https://web.archive.org/web/20231128043133im_/https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project"/> <meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA"/> <meta name="Generator" content="Drupal 10 (https://www.drupal.org)"/> <meta name="MobileOptimized" content="width"/> <meta name="HandheldFriendly" content="true"/> <meta name="viewport" content="width=device-width, initial-scale=1.0"/> <meta name="nist_search_modified" class="elastic" content="2017-07-19T11:45:00-04:00"/> <script type="application/ld+json">{ "@context": "https://web.archive.org/web/20231128043133/https://schema.org", "@graph": [ { "@type": "Article", "headline": "WUI Building and Fire Codes and Standards Project | NIST", "description": "Although over 46 million residential structures in the United States are in areas of risk of wildfires, building and fire codes and standards do not provide the same resiliency for structures in wildland-urban interface (WUI) communities as provided in urban communities. Projects within the Fire Risk Reduction in Communities Program seek (through laboratory experiments, field measurements, and computer modeling) to improve our understanding of WUI fire dynamics and structure ignition mechanisms. This measurement science will support standard test methods for building materials and assemblies, guidelines for structural design and residential landscaping, and guidelines for community planning. This project will improve WUI building and fire standards and codes using the results of the science-based WUI projects, including adoption by model building and fire codes. As these results are incorporated into improved building and fire codes, the resiliency or \u0022hardness\u0022 of each of the 70,000 communities that are at risk of wildland-urban interface fire will be improved.", "dateModified": "2017-07-19T11:45-04:00" } ] }</script> <meta name="nist_search_bundle" class="elastic" content="project_program"/> <link rel="icon" href="/web/20231128043133im_/https://www.nist.gov/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon"/> <title>WUI Building and Fire Codes and Standards Project | NIST</title> <link rel="stylesheet" media="all" href="/web/20231128043133cs_/https://www.nist.gov/sites/default/files/css/css_lr_VrGNCdV8eWWTN8NBFeKlBcrPb0w7sjAMAaKtlkAM.css?delta=0&language=en&theme=nist_www&include=eJx1kAFuwyAMRS_E6iNZDnFTtxBnNmmW2w_STkJdKyHk__myn4lqDNfvlW0PA8UbFq1nga7Gq398kqhzmFSnxEgzpb1IdHg1wixeMMl8k4JnSYUN_ls40SPoUljyYnpneDUazOGVC2euDJoGMsw6wihOQx3bmgbfvXCurM5HHqakA6W-_nq2ggvTyPYncdu2Pt3pFuGf0gbAaOtC6fSUwTUKJcw8CrWpEsNdeHM47lPlWxOHumVG4zMbz7HSGzO88TB6x5IlmrYv-AVGOKlX"/> <link rel="stylesheet" media="all" href="/web/20231128043133cs_/https://www.nist.gov/sites/default/files/css/css_6prwlieMvitJqVLptJ59w_NxX2prM0abXhYVoH12prk.css?delta=1&language=en&theme=nist_www&include=eJx1kAFuwyAMRS_E6iNZDnFTtxBnNmmW2w_STkJdKyHk__myn4lqDNfvlW0PA8UbFq1nga7Gq398kqhzmFSnxEgzpb1IdHg1wixeMMl8k4JnSYUN_ls40SPoUljyYnpneDUazOGVC2euDJoGMsw6wihOQx3bmgbfvXCurM5HHqakA6W-_nq2ggvTyPYncdu2Pt3pFuGf0gbAaOtC6fSUwTUKJcw8CrWpEsNdeHM47lPlWxOHumVG4zMbz7HSGzO88TB6x5IlmrYv-AVGOKlX"/> <link rel="stylesheet" media="print" href="/web/20231128043133cs_/https://www.nist.gov/sites/default/files/css/css_6MuKXqcH69mMwmOSjiD2G_c6UXIqUTZ1TRnur95k7Qk.css?delta=2&language=en&theme=nist_www&include=eJx1kAFuwyAMRS_E6iNZDnFTtxBnNmmW2w_STkJdKyHk__myn4lqDNfvlW0PA8UbFq1nga7Gq398kqhzmFSnxEgzpb1IdHg1wixeMMl8k4JnSYUN_ls40SPoUljyYnpneDUazOGVC2euDJoGMsw6wihOQx3bmgbfvXCurM5HHqakA6W-_nq2ggvTyPYncdu2Pt3pFuGf0gbAaOtC6fSUwTUKJcw8CrWpEsNdeHM47lPlWxOHumVG4zMbz7HSGzO88TB6x5IlmrYv-AVGOKlX"/> <link rel="stylesheet" media="all" href="/web/20231128043133cs_/https://www.nist.gov/sites/default/files/css/css_zxDJPMpCfrT8NQEavjogRlrVmShwu9oesPd2F7606bk.css?delta=3&language=en&theme=nist_www&include=eJx1kAFuwyAMRS_E6iNZDnFTtxBnNmmW2w_STkJdKyHk__myn4lqDNfvlW0PA8UbFq1nga7Gq398kqhzmFSnxEgzpb1IdHg1wixeMMl8k4JnSYUN_ls40SPoUljyYnpneDUazOGVC2euDJoGMsw6wihOQx3bmgbfvXCurM5HHqakA6W-_nq2ggvTyPYncdu2Pt3pFuGf0gbAaOtC6fSUwTUKJcw8CrWpEsNdeHM47lPlWxOHumVG4zMbz7HSGzO88TB6x5IlmrYv-AVGOKlX"/> <script src="/web/20231128043133js_/https://www.nist.gov/sites/default/files/js/js_3ssAdmvsW-btol8ydZT2eloQN8l11yuGacOobfI1-_0.js?scope=header&delta=0&language=en&theme=nist_www&include=eJx1kAFuwyAMRS_E6iNZDnFTtxBnNmmW2w_STkJdKyHk__myn4lqDNfvlW0PA8UbFq1nga7Gq398kqhzmFSnxEgzpb1IdHg1wixeMMl8k4JnSYUN_ls40SPoUljyYnpneDUazOGVC2euDJoGMsw6wihOQx3bmgbfvXCurM5HHqakA6W-_nq2ggvTyPYncdu2Pt3pFuGf0gbAaOtC6fSUwTUKJcw8CrWpEsNdeHM47lPlWxOHumVG4zMbz7HSGzO88TB6x5IlmrYv-AVGOKlX"></script> </head> <body class="node-418101"> <a href="#main-content" class="visually-hidden focusable" data-elastic-exclude> Skip to main content </a> <div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas> <!-- nist-index-ignore-start --> <section data-elastic-exclude class="usa-banner" aria-label="Official government website"> <div class="usa-accordion"> <header class="usa-banner__header"> <div class="usa-banner__inner"> <div class="grid-col-auto"> <img class="usa-banner__header-flag" src="/web/20231128043133im_/https://www.nist.gov/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag"> </div> <div class="grid-col-fill tablet:grid-col-auto"> <p class="usa-banner__header-text">An official website of the United States government</p> <p class="usa-banner__header-action" aria-hidden="true">Here鈥檚 how you know</p> </div> <button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default"> <span class="usa-banner__button-text">Here鈥檚 how you know</span> </button> </div> </header> <div class="usa-banner__content usa-accordion__content" id="gov-banner-default"> <div class="grid-row grid-gap-lg"> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20231128043133im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Official websites use .gov</strong> <br/> A <strong>.gov</strong> website belongs to an official government organization in the United States. </p> </div> </div> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20231128043133im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Secure .gov websites use HTTPS</strong> <br/> A <strong>lock</strong> ( <span class="icon-lock"> <svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false"> <title id="banner-lock-title">Lock</title> <desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg> </span> ) or <strong>https://</strong> means you鈥檝e safely connected to the .gov website. Share sensitive information only on official, secure websites. </p> </div> </div> </div> </div> </div> </section> <!-- nist-index-ignore-end --> <div data-elastic-exclude> <!-- nist-index-ignore-start --> <div class="nist-print-header" style="display:none;"> <p class="nist-print-header__url">https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project</p> <img class="nist-print-header__logo" width="289" height="38" src="/web/20231128043133im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology"/> </div> <div class="usa-overlay"></div> <header class="usa-header nist-header--www nist-header--minimal" role="banner"> <div class="usa-navbar"> <div class="usa-logo flex-fill"> <a href="/web/20231128043133/https://www.nist.gov/" title="National Institute of Standards and Technology" aria-label="Home"> <img src="/web/20231128043133im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px"/> </a> </div> <div class="usa-header__right grid-row flex-auto"> <div class="grid-col-fill nist-header__search-group"> <form class="usa-search usa-search--small" accept-charset="UTF-8" action="/web/20231128043133/https://www.nist.gov/search" id="search_form" method="get"> <div role="search"> <label class="usa-sr-only" for="search-form">Search NIST</label> <input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128"> <button class="usa-button" type="submit"><img src="/web/20231128043133im_/https://www.nist.gov/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button> </div> </form> </div> <div class="grid-col-auto padding-left-1"> <button class="usa-menu-btn">Menu</button> </div> </div> </div> <nav aria-label="Primary navigation" class="usa-nav"> <div class="usa-nav__inner"> <button class="usa-nav__close">Close</button> <ul class="usa-nav__primary usa-accordion"> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-1"><span>Topics</span></button> <div id="primary_menu-1" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/topics" class="usa-nav__link">All Topics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/advanced-communications" class="usa-nav__link">Advanced communications</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/bioscience" class="usa-nav__link">Bioscience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/buildings-construction" class="usa-nav__link">Buildings and construction</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/chemistry" class="usa-nav__link">Chemistry</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/climate" class="usa-nav__link">Climate</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/cybersecurity" class="usa-nav__link">Cybersecurity</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/electronics" class="usa-nav__link">Electronics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/energy" class="usa-nav__link">Energy</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/environment" class="usa-nav__link">Environment</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/fire" class="usa-nav__link">Fire</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/forensic-science" class="usa-nav__link">Forensic science</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/health" class="usa-nav__link">Health</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/information-technology" class="usa-nav__link">Information technology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/infrastructure" class="usa-nav__link">Infrastructure</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/manufacturing" class="usa-nav__link">Manufacturing</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/materials" class="usa-nav__link">Materials</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/metrology" class="usa-nav__link">Metrology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/nanotechnology" class="usa-nav__link">Nanotechnology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/neutron-research" class="usa-nav__link">Neutron research</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/performance-excellence" class="usa-nav__link">Performance excellence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/physics" class="usa-nav__link">Physics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/public-safety" class="usa-nav__link">Public safety</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/resilience" class="usa-nav__link">Resilience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/standards" class="usa-nav__link">Standards</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/transportation" class="usa-nav__link">Transportation</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <a class="usa-nav__link" href="/web/20231128043133/https://www.nist.gov/publications">Publications</a> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs & Major Programs</span></button> <div id="primary_menu-3" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/labs-major-programs/laboratories" class="usa-nav__link">Laboratories</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231128043133/https://www.nist.gov/ctl" class="usa-nav__link">Communications Technology Laboratory</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/el" class="usa-nav__link">Engineering Laboratory</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/itl" class="usa-nav__link">Information Technology Laboratory</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/mml" class="usa-nav__link">Material Measurement Laboratory</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/pml" class="usa-nav__link">Physical Measurement Laboratory</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/labs-major-programs/user-facilities" class="usa-nav__link">User Facilities</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231128043133/https://www.nist.gov/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/cnst" class="usa-nav__link">CNST NanoFab</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/laboratories/projects-programs" class="usa-nav__link">Research Projects</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/laboratories/tools-instruments" class="usa-nav__link">Tools & Instruments</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/labs-major-programs/major-programs" class="usa-nav__link">Major Programs</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231128043133/https://www.nist.gov/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/chips" class="usa-nav__link">CHIPS for America Initiative</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/oam" class="usa-nav__link">Office of Advanced Manufacturing</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/spo" class="usa-nav__link">Special Programs Office</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/tpo" class="usa-nav__link">Technology Partnerships Office</a> </li> </ul> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services & Resources</span></button> <div id="primary_menu-4" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/services-resources/standards-and-measurements" class="usa-nav__link">Standards and Measurements</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231128043133/https://www.nist.gov/calibrations" class="usa-nav__link">Calibration Services</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/nist-quality-system" class="usa-nav__link">Quality System</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/standardsgov" class="usa-nav__link">Standards.gov</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/pml/owm" class="usa-nav__link">Office of Weights and Measures</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/services-resources/software" class="usa-nav__link">Software</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/data" class="usa-nav__link">Data</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20231128043133/https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a> </li> <li> <a href="https://web.archive.org/web/20231128043133/https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/srd" class="usa-nav__link">Standard Reference Data (SRD)</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/shop" class="usa-nav__link">Storefront</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/tpo" class="usa-nav__link">License & Patents</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20231128043133/https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/nist-research-library" class="usa-nav__link">NIST Research Library</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News & Events</span></button> <div id="primary_menu-5" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/news-events/news" class="usa-nav__link">News</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/news-events/events" class="usa-nav__link">Events</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/blogs" class="usa-nav__link">Blogs</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/feature-stories" class="usa-nav__link">Feature Stories</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/awards" class="usa-nav__link">Awards</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/video-gallery" class="usa-nav__link">Video Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/image-gallery" class="usa-nav__link">Image Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/pao/media-contacts" class="usa-nav__link">Media Contacts</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button> <div id="primary_menu-6" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/about-nist" class="usa-nav__link">About Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/about-nist/contact-us" class="usa-nav__link">Contact Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/about-nist/visit" class="usa-nav__link">Visit</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/careers" class="usa-nav__link">Careers</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/director/nist-organization-structure" class="usa-nav__link">Our Organization</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231128043133/https://www.nist.gov/director" class="usa-nav__link">Office of the Director</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/director/nist-organization-structure/budget-planning" class="usa-nav__link">Budget & Planning</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/about-nist/work-nist" class="usa-nav__link">Work with NIST</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/history" class="usa-nav__link">History</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20231128043133/http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/nist-museum" class="usa-nav__link">NIST Museum</a> </li> <li> <a href="/web/20231128043133/https://www.nist.gov/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231128043133/https://www.nist.gov/education" class="usa-nav__link">Educational Resources</a> </li> </ul> </div> </div> </div> </li> </ul> </div> </nav> </header> <!-- nist-index-ignore-end --> </div> <div class="grid-container"> <div data-drupal-messages-fallback class="hidden"></div> </div> <div id="block-nist-www-content" class="nist-block"> <section class="nist-page__content usa-section clearfix"> <a id="main-content" tabindex="-1"></a> <div class="grid-container margin-top-4"> <div class="nist-page__region nist-page__region--content-top"> <div class="nist-block"> <a class="usa-button usa-button--accent-cool" href="/web/20231128043133/https://www.nist.gov/laboratories/projects-programs">PROJECTS/PROGRAMS</a> </div> <div class="nist-block"> <h1 class="nist-page__title">WUI Building and Fire Codes and Standards Project</h1> </div> <div class="nist-block"> <!-- nist-index-ignore-start --> <div data-elastic-exclude class="nist-block nist-social__wrapper"> <h2 class="nist-social__title">Share</h2> <div class="social-media-sharing"> <div class="nist-social__wrapper--share"> <div> <a target="_blank" rel="noopener" href="https://web.archive.org/web/20231128043133/https://www.facebook.com/share.php?u=https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project" title="Facebook" class="nist-social nist-social--facebook-gray"> <span>Facebook</span> </a> </div> <div> <a target="_blank" rel="noopener" href="https://web.archive.org/web/20231128043133/https://www.linkedin.com/shareArticle?mini=true&url=https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project&source=https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project" title="Linkedin" class="nist-social nist-social--linkedin-gray"> <span>Linkedin</span> </a> </div> <div> <a target="_blank" rel="noopener" href="https://web.archive.org/web/20231128043133/https://twitter.com/intent/tweet?url=https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project&status=https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project" title="Twitter" class="nist-social nist-social--twitter-gray"> <span>Twitter</span> </a> </div> <div> <a href="https://web.archive.org/web/20231128043133/mailto:/?subject=NIST.gov&body=Check out this site https://www.nist.gov/programs-projects/wui-building-and-fire-codes-and-standards-project" title="Email" class="nist-social nist-social--envelope-gray"> <span>Email</span> </a> </div> </div> </div> </div> <!-- nist-index-ignore-end --> </div> </div> </div> <div class="grid-container margin-top-4"> <div class="grid-row grid-gap-6"> <div class="nist-page__region nist-page__region--content tablet-lg:grid-col-8"> <div class="nist-block gray-box"> <div class="text-long"> <h2>Summary</h2> <p>Although over 46 million residential structures in the United States are in areas of risk of wildfires, building and fire codes and standards do not provide the same resiliency for structures in wildland-urban interface (WUI) communities as provided in urban communities. Projects within the Fire Risk Reduction in Communities Program seek (through laboratory experiments, field measurements, and computer modeling) to improve our understanding of WUI fire dynamics and structure ignition mechanisms. This measurement science will support standard test methods for building materials and assemblies, guidelines for structural design and residential landscaping, and guidelines for community planning. This project will improve WUI building and fire standards and codes using the results of the science-based WUI projects, including adoption by model building and fire codes. As these results are incorporated into improved building and fire codes, the resiliency or "hardness" of each of the 70,000 communities that are at risk of wildland-urban interface fire will be improved.</p> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Description</h2> <div class="text-with-summary"> <p><strong>Objective:</strong> By 2014, assess and integrate the current state-of-the-art risk reduction tools and practices into model building codes and standards for fires at the wildland-urban interface.</p><p><strong>What is the new technical idea?</strong> The new technical idea is to develop a national codes and standards strategy based on mapping zones of fire exposure severity within a WUI community. The fire exposure severity zoning system or exposure scale framework considers flame impingement, thermal radiative flux, and ember exposures and provides a basis for development of science-based performance metrics and representative test methodology for components, buildings, and communities. Since the fire severity scale is based on the exposure to flames and embers and not on specific vegetation or materials, the exposure scale will be broadly applicable across WUI communities. More representative metrics and test methods will allow new materials, designs, and technologies to be evaluated under more realistic conditions. As building codes and standards incorporate a fire exposure mapping system, the fire resistance of WUI communities will increase in a manner analogous to the use of the Richter Scale for increasing the earthquake resistance of buildings and communities. Construction in each fire exposure zone will meet the appropriate codes and standards. Established communities in each fire exposure zone would need to consider building retrofit and community and parcel<sup>[1]</sup> landscaping guidance developed by NIST to address WUI fire hazards.</p><p>There is also a need to develop a better understanding of the relationship between the cost a community pays for fire protection, the level of protection afforded, and the losses resulting from a WUI fire. For example, if a community were to require a 30 m spacing between structures, what is the economic cost to the community? How much additional protection does a 30 m spacing provide? In the case of a fire spreading by thermal radiation, 30 m rather than 10 m spacing may increase the resistance to fire spread by a factor of 10. On the other hand, in the case of fire spread by ember ignition, 30 m spacing may provide little additional fire protection. Exposure to flames and embers must be considered in the development of metrics to assess the performance of individual structures and the community during a WUI fire.</p><p>Currently doing a cost/benefit analysis is hampered by the lack of understanding as to the relative contributions of the factors such as structural spacing, distance to wildland, topography, and fuel treatments. A second new technical idea is to use statistical methods to evaluate the relative contribution of various factors that affect structure ignitions during WUI fires. These findings will aid in the prioritization of research to assess the influence of exposure conditions and mitigation approaches on structure risk during WUI fire incidents.</p><p><strong>What is the research plan?</strong> The primary focus of the research effort will be the development of a national strategy for WUI codes and standards, including model building codes to reduce losses in WUI fires. The foundation of the approach will be a nationally applicable WUI community fire-exposure zoning system, WUI performance metrics, and building and fire codes.</p><p><em>WUI Technical Solution Implementation Guide聽</em><br/>A WUI technical solution implementation guide will be developed for existing and new communities. The WUI fire-exposure zone concept will form the basis of the guide. The first generation of the WUI Technical Solution Implementation Guide will be based on existing expert knowledge. A science-based approach will improve subsequent versions by incorporating lab-scale and field-scale experiments, post-fire data collection, and fire spread and economic models.</p><p>The guide will serve two purposes. First, the guide will provide a centralized repository of all WUI fire research technical findings. Secondly, the guide will establish a framework that will identify the gaps in WUI hazard reduction solutions that are implementable and relevant to the WUI problem. The guide will be revised every two years. The results of experiments, analysis, modeling, and post-fire data collection and analysis will be essential to the development of this guide.</p><p><em>Suppression of Wildland Fires versus Hardening WUI Communities</em><br/>The traditional approach to preventing WUI fires has been to focus resources and efforts on suppressing fire in the wildland. If all wildland fires were successfully extinguished then there would be no fires to spread from the wildland to the community. This suppression approach has focused most of the effort and resources on wildfire suppression to the exclusion of improving the fire resistance of communities. Increasing the fire resistance or hardening the communities involves making it more difficult to ignite structures and if ignition occurs, limiting the fire spread. WUI building codes and standards need to shift the research emphasis to hardening the community through less ignition-prone materials, more fire resistant designs, and new technologies to prevent fire spread within communities with less emphasis on wildland fuels management and suppression.</p><p><em>WUI Fire Data in the Disaster and Failure Studies (DFS) Data Repository</em><br/>WUI field experimental and post-fire data is being collected as part of the WUI Fire Data Collection and Exposure Modeling Project and is being incorporated into the DFS Data Repository. However, while this data is currently used to develop WUI fire spread models and performance metrics, it can also be exploited to document the effectiveness of current building codes and standards and to establish a baseline to track improvement. The findings of post-fire analysis such as the ignition of wood decks will be used to assess whether specific modifications to the wood deck code provisions actually reduced the number of wood deck fires and subsequent spread to homes. Data will also be valuable as the DFS Data Repository is used to examine trends and common factors influencing the impact of WUI fires.</p><p><em>Evaluate the relative contribution of different fire exposure elements</em><br/>Measuring the fire resiliency of wildland-urban interface (WUI) communities requires: 1) understanding the relative contribution of fuel package configuration, weather, and terrain, 2) quantifying the cost of providing the current level of fire protection, 3) understanding the losses resulting from WUI fires, and 4) using performance metrics to assess the effectiveness of current designs, materials, and technologies. The research plan is to begin understanding the relative contribution of these different elements. This effort will link economic outcomes with mitigation actions, and thereby provide performance metrics to assess the effectiveness of community fire protection strategies.</p><hr/><p>[1] Section of contiguous land with its structures, driveways, and vegetation; may be single home or group of adjoining homes.</p> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Major Accomplishments</h2> <div class="text-long"><p><strong>Recent Results:</strong></p><p><strong>Workshop:</strong></p><p>A WUI Fire Research Needs Workshop was conducted on August 15-16, 2012 in Boulder, CO. Participants included International Code Council, National Fire Protection Association, US Forest Service, Insurance Institute for Building and Home Safety, US Fire Administration, California Department of Forestry and Fire Prevention (CALFIRE) International Association of Fire Fighters (IAFF), International Association of Fire Chiefs (IAFC), National Wildfire Coordinating Group (NWCG), industry, fire service, authorities having jurisdiction (AHJ), and San Diego State University.聽</p><p><strong>Outputs:</strong></p><p>Maranghides, A., and Mell, W., "Creating a Framework for Addressing the National Wildland Urban Interface Problem Using the E-Scale," to be submitted to Fire Engineering (in WERB review, June 2011).</p><p>Thomas, D.S., and D.T. Butry. 2012.<a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/publications/wildland-fires-within-municipal-jurisdictions">"Wildland Fires</a><sup>[2]</sup><a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/publications/wildland-fires-within-municipal-jurisdictions">within Municipal Jurisdictions."</a> Journal of Forestry 110(1): 34-41.</p><p>Developed framework<sup>[3]</sup> for assessing community scale fire risk. Bryner and Johnsson, "Framework For Assessing Community-Scale Fire Risk," NIST Technical Note, 2012, in preparation.</p><p>Butry, D.T., J.P. Prestemon, K.L. Abt, and R. Sutphen. 2010. <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/publications/economic-optimization-wildfire-intervention-activities">"Economic Optimization of Wildfire Intervention Activities."</a> International Journal of Wildland Fire 19: 659-672.</p><p>Butry, D.T., D.S. Thomas, G.H. Donovan, and P. Lavappa. "The Role of Building Density in Wildland-Urban Interface Fires." (in Review).</p><p>Thomas, D.S., and D.T. Butry. "High Fire-Frequency Wildland-Urban Interface Areas." Journal of Forestry, 2012. (in Review).</p><p>Economic model of community-based mitigation accounting for the spatial spillover of individual homeowner mitigation efforts, and construction of a GIS data library to facilitate WUI community wildland fire risk analysis (Butry, Thomas, & Lavappa).</p><p><strong>Standards and Codes:聽</strong></p><p>This project will focus on hardening communities that are exposed to WUI fires by incorporating the exposure scale into building codes and standards including 2012 International Wildland-Urban Interface Code (ICC), 2009 Wildland Urban Building Code, California Chapter 7A Building Code, 2013 Standard for Reducing Structure Ignition Hazards from Wildland Fire (NFPA 1144). Researchers are members of and participate on Fire/Performance/Wildland-Urban Interface Committee, FI PC WU 鈥揑CC (Bryner) and Technical Committee on Forest and Rural Fire Protection (Maranghides), Quantification of Exterior Fire Exposures, ASTM E05.14 (Manzello). The economic model will be incorporated into NFPA 1144 Committee on Forest and Rural Fire Protection to implement the use of the economic decision support tool as a standard method facilitating community risk assessment and disaster planning. The strategic roadmap<sup>[4]</sup> and workshop proceedings also provide documentation of the WUI codes and standards strategy.<sup>[5]</sup></p><p>聽</p><hr/><p>[2] WUI fires is not univesally used to describe fire in wildland-urban interface communities. This reference uses wildland fire within municipal jurisdictions instead of WUI fires.</p><p>[3] Approach used Risk f(Vulnerability x Loss or Consequences x Threat) and Framework incorporates three components: 1) Exposure to Hazard, 2) Response of Structure/Community, and 3) Designs to Mitigate Risk</p><p>[4] <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/publications/strategic-roadmap-fire-risk-reduction-buildings-and-communities">"Reduced Risk of Fire in Buildings and Communities: A Strategic Roadmap to Prioritize and Guide Research,"</a> NIST Special Publication 1130, April 2012.</p><p>[5] NIST Workshop on Wildland-Urban Interface Fire Research Needs, August 15-16, 2012, Boulder, CO, Draft Proceeding 9/2012.</p></div> </div> <div class="nist-block"> <!-- nist-index-ignore-start --> <div data-elastic-exclude="" class="nist-tags"> <a href="/web/20231128043133/https://www.nist.gov/topic-terms/building-codes-and-standards" hreflang="en">Building codes and standards</a>, <a href="/web/20231128043133/https://www.nist.gov/topic-terms/fire" hreflang="en">Fire</a> and <a href="/web/20231128043133/https://www.nist.gov/topic-terms/standards" hreflang="en">Standards</a></div> <!-- nist-index-ignore-end --> </div> </div> <aside class="nist-page__region nist-page__region--sidebar-second tablet-lg:grid-col-4"> <div> <!-- nist-index-ignore-start --> <div class="views-element-container nist-block nist-block--org" data-elastic-exclude=""> <h2 class="nist-block__title">Organizations</h2> <div><div class="js-view-dom-id-183b78a6daf7ab6ce24c55c1e92abfbbda51a8965252b43d67688fa61ba10627"> <div class="nist-related-orgs"><div class="term-tree-list"> <ul class="term"><li><a href="/web/20231128043133/https://www.nist.gov/nist-organizations/nist-headquarters" class="selected" hreflang="en">NIST Headquarters</a></li><li><ul class="term"><li><a href="/web/20231128043133/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs" class="selected" hreflang="en">Laboratory Programs</a></li><li><ul class="term"><li><a href="/web/20231128043133/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs/engineering-laboratory" class="selected" hreflang="en">Engineering Laboratory</a></li><li><ul class="term"><li><a href="/web/20231128043133/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs/engineering-laboratory/fire-research" class="selected" hreflang="en">Fire Research Division</a></li><li><ul class="term"><li><a href="/web/20231128043133/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs/engineering-laboratory/fire-research-2" class="selected" hreflang="en">Wildland Urban Interface Fire Group</a></li></ul></li></ul></li></ul></li></ul></li></ul> </div> </div> <div class="nist-related-orgs"></div> <div class="nist-related-orgs"></div> <div class="nist-related-orgs"></div> <div class="nist-related-orgs"></div> <div class="nist-related-orgs"></div> </div> </div> </div> <!-- nist-index-ignore-end --> <div class="nist-block"> <h2 class="nist-block__title">Project Status</h2> <div class="nist-badge display-inline-block margin-y-1 nist-badge--green boolean">Completed</div> </div> <div class="nist-block"> <h2 class="nist-block__title">Related NIST Projects</h2> <div class="nist-field nist-field--label-hidden nist-field--link-list entity-reference"> <div class="nist-field__items"> <div class="nist-field__item"><a href="/web/20231128043133/https://www.nist.gov/programs-projects/fire-risk-reduction-communities-program" hreflang="en">Fire Risk Reduction in Communities Program</a></div> </div> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Facilities</h2> <div class="text-long"><p><a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/laboratories/tools-instruments/national-fire-research-laboratory">The National Fire Research Laboratory</a></p></div> </div> </div> </aside> </div> </div> <div class="grid-container"> <div class="nist-page__region nist-page__region--content-bottom"> <div class="nist-block"> <div class="text-italic font-sans-2xs"> Created November 2, 2011, Updated July 19, 2017 </div> </div> </div> </div> </section> </div> <div data-elastic-exclude> <!-- nist-index-ignore-start --> <footer class="nist-footer padding-bottom-4"> <div class="grid-container nist-footer__info"> <div class="grid-row"> <div class="tablet:grid-col-6"> <div class="nist-footer__logo"> <a href="/web/20231128043133/https://www.nist.gov/" title="National Institute of Standards and Technology" rel="home"> <img class="nist-footer__logo-img" src="/web/20231128043133im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px"/> </a> </div> <div class="nist-footer__contact"> <h3 class="nist-footer__contact-heading">HEADQUARTERS</h3> <address> 100 Bureau Drive<br> Gaithersburg, MD 20899<br> <a href="https://web.archive.org/web/20231128043133/tel:301-975-2000">301-975-2000</a> </address> <p> <a href="https://web.archive.org/web/20231128043133/mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/visit">Our Other Offices</a> </p> </div> </div> <div class="tablet:grid-col-6"> <div class="nist-footer__social-links"> <a class="nist-social nist-social--twitter-white" href="https://web.archive.org/web/20231128043133/https://twitter.com/NIST"> <span>Twitter</span> </a> <a class="nist-social nist-social--facebook-white" href="https://web.archive.org/web/20231128043133/https://www.facebook.com/NIST"> <span>Facebook</span> </a> <a class="nist-social nist-social--linkedin-white" href="https://web.archive.org/web/20231128043133/https://www.linkedin.com/company/nist"> <span>LinkedIn</span> </a> <a class="nist-social nist-social--instagram-white" href="https://web.archive.org/web/20231128043133/https://www.instagram.com/nist/"> <span>Instagram</span> </a> <a class="nist-social nist-social--youtube-white" href="https://web.archive.org/web/20231128043133/https://www.youtube.com/NIST"> <span>YouTube</span> </a> <a class="nist-social nist-social--giphy-white" href="https://web.archive.org/web/20231128043133/https://giphy.com/nist"> <span>Giphy</span> </a> <a class="nist-social nist-social--rss-white" href="https://web.archive.org/web/20231128043133/https://www.nist.gov/news-events/nist-rss-feeds"> <span>RSS Feed</span> </a> <a class="nist-social nist-social--envelope-white" href="https://web.archive.org/web/20231128043133/https://public.govdelivery.com/accounts/USNIST/subscriber/new"> <span>Mailing List</span> </a> </div> <div class="nist-footer__feedback"> How are we doing? <a class="usa-button" rel="nofollow" href="/web/20231128043133/https://www.nist.gov/form/nist-gov-feedback?destination=/programs-projects/wui-building-and-fire-codes-and-standards-project" title="Provide feedback">Feedback</a> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-footer__nav" role="navigation"> <ul> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/privacy-policy">Site Privacy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/oism/accessibility">Accessibility</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/privacy">Privacy Program</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/oism/copyrights">Copyrights</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/office-director/freedom-information-act">FOIA</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/environmental-policy-statement">Environmental Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://www.commerce.gov/">Commerce.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/http://www.science.gov/">Science.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/http://www.usa.gov/">USA.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231128043133/https://vote.gov/">Vote.gov</a> </li> </ul> </div> </div> </footer> <!-- nist-index-ignore-end --> </div> </div> <script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","scriptPath":null,"pathPrefix":"","currentPath":"node\/418101","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":"","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"append","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"user":{"uid":0,"permissionsHash":"2f77e4dcfce20728ac491170886da836c10b580f9bdfeb9c9e729fe4958834d5"}}</script> <script src="/web/20231128043133js_/https://www.nist.gov/sites/default/files/js/js_wWC32cBD9qab55wFkKWKvOdi_p-P8cBjregEiEdV1z4.js?scope=footer&delta=0&language=en&theme=nist_www&include=eJx1kAFuwyAMRS_E6iNZDnFTtxBnNmmW2w_STkJdKyHk__myn4lqDNfvlW0PA8UbFq1nga7Gq398kqhzmFSnxEgzpb1IdHg1wixeMMl8k4JnSYUN_ls40SPoUljyYnpneDUazOGVC2euDJoGMsw6wihOQx3bmgbfvXCurM5HHqakA6W-_nq2ggvTyPYncdu2Pt3pFuGf0gbAaOtC6fSUwTUKJcw8CrWpEsNdeHM47lPlWxOHumVG4zMbz7HSGzO88TB6x5IlmrYv-AVGOKlX"></script> <script src="https://web.archive.org/web/20231128043133js_/https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script> <script src="/web/20231128043133js_/https://www.nist.gov/sites/default/files/js/js_os59nuR5zggldWlpN64lVOtwfILbqHxATX9Bq3PXLA8.js?scope=footer&delta=2&language=en&theme=nist_www&include=eJx1kAFuwyAMRS_E6iNZDnFTtxBnNmmW2w_STkJdKyHk__myn4lqDNfvlW0PA8UbFq1nga7Gq398kqhzmFSnxEgzpb1IdHg1wixeMMl8k4JnSYUN_ls40SPoUljyYnpneDUazOGVC2euDJoGMsw6wihOQx3bmgbfvXCurM5HHqakA6W-_nq2ggvTyPYncdu2Pt3pFuGf0gbAaOtC6fSUwTUKJcw8CrWpEsNdeHM47lPlWxOHumVG4zMbz7HSGzO88TB6x5IlmrYv-AVGOKlX"></script> <script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"gov-bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFnFGRhVWVWoNVgUHaHpaWkcXWFVaBks9LFtdUGJaAEB6WQ1NEw1YVVBGHltBUFMU","queueTime":4,"applicationTime":703,"atts":"TBtXQQMaH0k=","errorBeacon":"gov-bam.nr-data.net","agent":""}</script></body> </html> <!-- FILE ARCHIVED ON 04:31:33 Nov 28, 2023 AND RETRIEVED FROM THE INTERNET ARCHIVE ON 15:58:28 Dec 11, 2024. JAVASCRIPT APPENDED BY WAYBACK MACHINE, COPYRIGHT INTERNET ARCHIVE. ALL OTHER CONTENT MAY ALSO BE PROTECTED BY COPYRIGHT (17 U.S.C. SECTION 108(a)(3)). --> <!-- playback timings (ms): captures_list: 0.796 exclusion.robots: 0.042 exclusion.robots.policy: 0.026 esindex: 0.015 cdx.remote: 5.446 LoadShardBlock: 249.213 (3) PetaboxLoader3.resolve: 245.876 (4) PetaboxLoader3.datanode: 80.609 (4) load_resource: 125.269 -->