{"hq_id":"hq-c-org-000238","name":"MTBE (methyl tert-butyl ether)","context":"human_adult","timestamp":"2026-10-27T17:55:17.246Z","derived_by":{"label":"ALETHEIA-derived","engine":{"commit":"a1c6e861599cc34c5db0318ea1a7ac13a327e074","commit_source":"vercel_env","tree_clean":null},"params":{"sha256":"88ae43137e58ed0cd65588409efefee0d90253da01ef4459bf9ee25f888ec9a0","files":["axes.json","context-specificity.json","regulatory-mappings.json","synthesis-params.json","thresholds.json"]},"clock":{"year":2026},"inputs":[{"id":"hq-c-org-000238","sha256":"c1c4a1aa11ddb9e89b2d7f01b650a700982c8e0b35b43f5c80335503863734f5"}]},"risk_level":"moderate_to_high","risk_profile":{"magnitude":{"mean":0.440171,"weightedMean":0.440171,"std_dev":0.091577,"confidence_interval_95":[0.3,0.5],"source_positions":[{"source":"EPA CTX / IARC","year":2026,"value":0.5,"weight":0.82},{"source":"HQ_DIRECT","year":2026,"value":0.3,"weight":0.35}]},"confidence":{"mean":0.724274,"weightedMean":0.724274,"std_dev":0.146523,"confidence_interval_95":[0.5,0.82],"source_positions":[{"source":"HQ_DIRECT","year":2026,"value":0.5,"weight":0.35},{"source":"EPA CTX / IARC","year":2026,"value":0.82,"weight":0.82}]},"recency":{"mean":1,"weightedMean":1,"std_dev":0,"confidence_interval_95":[1,1],"source_positions":[{"source":"HQ_DIRECT","year":2026,"value":1,"weight":0.35},{"source":"EPA CTX / IARC","year":2026,"value":1,"weight":0.82}]},"methodology":{"mean":0.910256,"weightedMean":0.910256,"std_dev":0.137365,"confidence_interval_95":[0.7,1],"source_positions":[{"source":"HQ_DIRECT","year":2026,"value":0.7,"weight":0.35},{"source":"EPA CTX / IARC","year":2026,"value":1,"weight":0.82}]},"specificity":{"mean":0.800855,"weightedMean":0.800855,"std_dev":0.07784,"confidence_interval_95":[0.75,0.92],"source_positions":[{"source":"HQ_DIRECT","year":2026,"value":0.92,"weight":0.35},{"source":"EPA CTX / IARC","year":2026,"value":0.75,"weight":0.82}]},"consensus":{"exists":false,"strength":0.389487,"disagreement_magnitude":0.228604,"warning":"limited_synthesis"}},"interpretation":{"summary":"Regulatory agencies show substantial disagreement. EPA CTX / IARC classifies as higher risk (50th percentile), while HQ_DIRECT concludes lower risk (30th percentile).","confidence_note":"Moderate-quality evidence base. Disagreement reflects methodological and interpretive differences, not data quality issues.","context_note":null,"warning":"limited_synthesis"},"sources":[{"id":"epa_mtbe_advisory_1997","type":"regulatory","title":"US EPA: Drinking Water Advisory: Consumer Acceptability Advice and Health Effects Analysis on Methyl Tertiary-Butyl Ether (MTBE) — Taste/Odor Threshold 20–40 μg/L, No Federal MCL Established (1997)","year":1997},{"id":"who_dwq_guidelines_2022","type":"regulatory","title":"WHO Guidelines for Drinking-water Quality (4th edition, incorporating the 1st and 2nd addenda, 2022) — Disinfection Byproducts: THMs, HAAs, Chlorite, Bromate, Chloral Hydrate; Guideline Values and Health Basis","year":2022},{"id":"r60-2026-09-26-d867-cc1-iarc-list-of-classifications-loc-app","type":"regulatory","title":"IARC Monographs, List of Classifications","year":2026,"url":"https://monographs.iarc.who.int/list-of-classifications"},{"id":"r60-2026-10-01-dd54-hc-trvs-v2-h128-1-11-638","type":"regulatory","title":"Federal Contaminated Site Risk Assessment in Canada, Part II: Health Canada Toxicological Reference Values (TRVs) and Chemical-Specific Factors, Version 2.0","url":"http://publications.gc.ca/collections/collection_2012/sc-hc/H128-1-11-638-eng.pdf"},{"id":"r60-2026-10-01-echa-annex-vi-clp-table-atp23-xlsx","type":"regulatory","title":"ECHA Annex VI to CLP: the unofficial Excel table (up to and including the 23rd ATP) (secondary: unofficial by its own statement)","url":"https://echa.europa.eu/documents/10162/17218/annex_vi_clp_table_atp23_en.xlsx/b3816c13-81a3-816d-773a-62e88c4e2700?t=1761727004499"},{"id":"echa-chem-reach-registrations","type":"regulatory","title":"ECHA CHEM, Download all substances: REACH registrations (ECHA's own list of REACH-registered substances)","year":2026,"url":"https://chem.echa.europa.eu/"},{"id":"src_pubchem_tox_15413","type":"pubchem","title":"PubChem: Toxicity section (CID 15413)","url":"https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/15413/JSON?heading=Toxicity"},{"id":"r60-2026-10-03-d928-cellar-02009l0161-20180821","type":"regulatory","title":"Consolidated TEXT: 32009L0161 — EN — 21.08.2018","url":"https://publications.europa.eu/resource/celex/02009L0161-20180821"},{"id":"r60-2026-09-30-d918-oehha-prop65-list-csv-own-url","type":"regulatory","title":"OEHHA Proposition 65 List of Carcinogens or Reproductive Toxicants (CSV, list date 31-Jul-26)","url":"https://oehha.ca.gov/sites/default/files/media/2025-01/p65chemicalslist.csv"},{"id":"pubchem-exp-cameo-chemicals-cid-15413","type":"database","title":"CAMEO Chemicals, as recorded by PubChem (Experimental Properties, CID 15413; where-to-look, not a source of this value)","year":2026,"url":"https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/15413/JSON?heading=Experimental+Properties"},{"id":"pubchem-exp-hazardous-substances-data-bank-cid-15413","type":"database","title":"Hazardous Substances Data Bank (HSDB), as recorded by PubChem (Experimental Properties, CID 15413; where-to-look, not a source of this value)","year":2026,"url":"https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/15413/JSON?heading=Experimental+Properties"},{"id":"ctx_pred_dtxsid3020833","type":"reference","title":"EPA CompTox CTX API: predicted properties for DTXSID3020833 (MTBE (methyl tert-butyl ether))","url":"https://comptox.epa.gov/ctx-api/chemical/property/predicted/search/by-dtxsid/DTXSID3020833"}],"sources_scope":"context","derived_markers":[],"warnings":["unmapped_classification:EPA CTX / Health Canada:group vi: cepa (unclassifiable with respect to car","unmapped_classification:EPA CTX / Health Canada:group via: cepa (unclassifiable with respect to ca","unmapped_classification:US EPA (CompTox genotoxicity summary):epa comptox computed genotoxicity summary: positiv","unmapped_classification:US EPA (CompTox genotoxicity summary):epa comptox computed genotoxicity summary: positiv","unmapped_classification:ECHA (CLP Annex VI):skin irritation: skin irrit. 2","unmapped_classification:Japan, as recorded by ToxValDB:eye irritation: category 2b (score: moderate)","unmapped_classification:Japan, as recorded by ToxValDB:skin irritation: category 2 (score: high)","unmapped_classification:Japan, as recorded by ToxValDB:skin sensitization: not classified (score: low)","limited_synthesis"],"meta":{"synthesis_version":"1.1.0","config_version":"1.1.0","n_sources":2,"db_version":49,"warnings":["unmapped_classification:EPA CTX / Health Canada:group vi: cepa (unclassifiable with respect to car","unmapped_classification:EPA CTX / Health Canada:group via: cepa (unclassifiable with respect to ca","unmapped_classification:US EPA (CompTox genotoxicity summary):epa comptox computed genotoxicity summary: positiv","unmapped_classification:US EPA (CompTox genotoxicity summary):epa comptox computed genotoxicity summary: positiv","unmapped_classification:ECHA (CLP Annex VI):skin irritation: skin irrit. 2","unmapped_classification:Japan, as recorded by ToxValDB:eye irritation: category 2b (score: moderate)","unmapped_classification:Japan, as recorded by ToxValDB:skin irritation: category 2 (score: high)","unmapped_classification:Japan, as recorded by ToxValDB:skin sensitization: not classified (score: low)"]},"schema":"synthesis","_notice":"ALETHEIA output is reference data, not professional advice. Not a substitute for primary agency sources or qualified professionals. See https://aletheia.holisticquality.io/disclaimer.","_disclaimer_url":"https://aletheia.holisticquality.io/disclaimer","available_contexts":["human_adult","human_child","exposure_ingestion","human_teen","human_elderly","human_infant","human_pregnant"]}