A methodology for integrating human toxicity during the use stage into building life cycle assessment

A methodology for integrating human toxicity during the use stage into building life cycle assessment | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article A methodology for integrating human toxicity during the use stage into building life cycle assessment Belén Rey-Álvarez, Benito Sánchez-Montañés, Antonio García-Martínez This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8865647/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose This paper develops a reproducible calculation procedure to integrate human toxicity from construction material emissions during the use stage into building LCA, focusing on module B1 (EN 15978). The research evaluates whether a building inventory (elements, materials and product documentation) can be translated into a substance-resolve B1 emission inventory by compartment (household indoor or outdoor) and subsequently characterised with USEtox, while preserving traceability and operability with commonly available data. Methods The method follows a four step workflow: (1) disaggregation of the building into Level(s) elements, materials and substances; (2) conversion of contained mass to cumulative B1 emissions through an explicit rules matrix (physicochemical class crossed with construction position) assigning indoor or outdoor compartments; (3) impact characterisation using USEtox compartment specific factors (CTUh and DALY); and (4) hierarchical aggregation (substance to material to element to building) with contribution analysis. Substances lacking a USEtox characterisation factor are retained as identified but assigned CF = 0. Coverage metrics are reported to delimit the evaluated fraction, ensuring that the portion of the inventory not characterised remains visible as a data availability issue. Results and discussion Application to a two-storey detached house reveals two dominant patterns. First, impacts are concentrated almost entirely in the household indoor compartment, consistent with higher exposure potential under confined conditions. Second, results are highly concentrated in a small set of elements and materials (notably insulation, primers and sealants), while many elements remain at zero. This sparsity reflects both methodological filters (emission rules) and data constraints (compositional disaggregation and USEtox coverage). Therefore, “zero” contributions must be interpreted as an evaluation zone limited by data rather than intrinsic harmlessness. The findings highlight the structural gap between building scale decision making and the effective availability of characterisation factors at the substance scale, identifying where further chemical documentation is most critical. Conclusions A transparent, traceable bridge between building inventories and USEtox characterisation can be implemented for B1 without dynamic IAQ modelling, enabling screening and comparative prioritisation during design and specification. The results demonstrate that practical uptake depends more on chemical traceability and coverage than on model sophistication, positioning this method as a base for moving from carbon focused evaluations towards health sensitive design decisions. Indoor air quality (IAQ) Emissions during use Emissions inventory Chemical transparency Characterisation factors Building materials Exposure assessment Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8865647","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":590505976,"identity":"3ff3df40-7088-4ca9-b715-12534aeb7cd2","order_by":0,"name":"Belén Rey-Álvarez","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAl0lEQVRIiWNgGAWjYLCChAqStTw4Q6oOxodtpCjXnX34mETivMP2DOztD4jTYnYuLU0icdvhxAaeMwZEajnDYwbSksAgkUOkw8zO8H+TSJwDdJj8c2IddoaHTSKx4TBjgwQD0Q5jM7ZIOJae2MaTQ7QW5oc3f9RY2/OzHyfSYUDAIgEi2YhWDwTMH0hRPQpGwSgYBSMQAABADyk1nBW9fAAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-3763-7008","institution":"University of Seville","correspondingAuthor":true,"prefix":"","firstName":"Belén","middleName":"","lastName":"Rey-Álvarez","suffix":""},{"id":590505977,"identity":"40729483-4542-4c33-b963-17b826c1ff81","order_by":1,"name":"Benito Sánchez-Montañés","email":"","orcid":"","institution":"University of Seville","correspondingAuthor":false,"prefix":"","firstName":"Benito","middleName":"","lastName":"Sánchez-Montañés","suffix":""},{"id":590505978,"identity":"466d1e1f-2106-4fac-8fde-1cdc54d04af0","order_by":2,"name":"Antonio García-Martínez","email":"","orcid":"","institution":"University of Seville","correspondingAuthor":false,"prefix":"","firstName":"Antonio","middleName":"","lastName":"García-Martínez","suffix":""}],"badges":[],"createdAt":"2026-02-12 21:13:09","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-8865647/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8865647/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eA methodology for integrating human toxicity during the use stage into building life cycle assessment\u003c/strong\u003e\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Indoor air quality (IAQ), Emissions during use, Emissions inventory, Chemical transparency, Characterisation factors, Building materials, Exposure assessment","lastPublishedDoi":"10.21203/rs.3.rs-8865647/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8865647/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eThis paper develops a reproducible calculation procedure to integrate human toxicity from construction material emissions during the use stage into building LCA, focusing on module B1 (EN 15978). The research evaluates whether a building inventory (elements, materials and product documentation) can be translated into a substance-resolve B1 emission inventory by compartment (household indoor or outdoor) and subsequently characterised with USEtox, while preserving traceability and operability with commonly available data.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThe method follows a four step workflow: (1) disaggregation of the building into Level(s) elements, materials and substances; (2) conversion of contained mass to cumulative B1 emissions through an explicit rules matrix (physicochemical class crossed with construction position) assigning indoor or outdoor compartments; (3) impact characterisation using USEtox compartment specific factors (CTUh and DALY); and (4) hierarchical aggregation (substance to material to element to building) with contribution analysis. Substances lacking a USEtox characterisation factor are retained as identified but assigned CF\u0026thinsp;=\u0026thinsp;0. Coverage metrics are reported to delimit the evaluated fraction, ensuring that the portion of the inventory not characterised remains visible as a data availability issue.\u003c/p\u003e\u003ch2\u003eResults and discussion\u003c/h2\u003e \u003cp\u003eApplication to a two-storey detached house reveals two dominant patterns. First, impacts are concentrated almost entirely in the household indoor compartment, consistent with higher exposure potential under confined conditions. Second, results are highly concentrated in a small set of elements and materials (notably insulation, primers and sealants), while many elements remain at zero. This sparsity reflects both methodological filters (emission rules) and data constraints (compositional disaggregation and USEtox coverage). Therefore, \u0026ldquo;zero\u0026rdquo; contributions must be interpreted as an evaluation zone limited by data rather than intrinsic harmlessness. The findings highlight the structural gap between building scale decision making and the effective availability of characterisation factors at the substance scale, identifying where further chemical documentation is most critical.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eA transparent, traceable bridge between building inventories and USEtox characterisation can be implemented for B1 without dynamic IAQ modelling, enabling screening and comparative prioritisation during design and specification. The results demonstrate that practical uptake depends more on chemical traceability and coverage than on model sophistication, positioning this method as a base for moving from carbon focused evaluations towards health sensitive design decisions.\u003c/p\u003e","manuscriptTitle":"A methodology for integrating human toxicity during the use stage into building life cycle assessment","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-16 08:29:00","doi":"10.21203/rs.3.rs-8865647/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e5be4972-c972-4179-a02b-2bea3ac92b57","owner":[],"postedDate":"February 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-02-16T08:29:01+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-16 08:29:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8865647","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8865647","identity":"rs-8865647","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}