{"hq_id":"hq-p-spe-000039","name":"Brake fluid (DOT 3/4)","category":{"primary":"specialty","secondary":"automotive","tags":["brake fluid","glycol ether","automotive","DOT 3","DOT 4"]},"product_tier":"SPE","overall_risk_level":"moderate_to_high","description":"Hydraulic brake fluid based on polyethylene glycol ethers (polyalkylene glycol). DOT 3 and DOT 4 are the most common consumer grades. Contains glycol ethers that are skin/eye irritants and CNS depressants at high exposure. Ingestion causes metabolic acidosis similar to ethylene glycol poisoning. Attacks paint and most plastics on contact. Hygroscopic — absorbs atmospheric moisture over time, lowering boiling point and degrading brake performance.","synthesis":{"derived_risk_level":"low","synthesis_confidence":0.5,"synthesis_method":"compound_composition","context_used":"human_adult","context_source":"product_users","exposure_modifier":1,"vulnerability_escalated":false,"escalation_reason":null,"compounds_resolved":1,"compounds_total":1,"synthesis_date":"2026-05-09","synthesis_version":"1.2.0","methodology_note":"exposure_modifier and adjusted_magnitude are computed from ALETHEIA-calibrated heuristics (route × duration × frequency multipliers, clamped to [0.5, 1.4]). Multipliers are directionally informed by EPA Exposure Factors Handbook (2011) and CalEPA OEHHA but are not regulatory consensus. See /api/methodology for full disclosure."},"hazard_summary":{"sensitive_populations":"adult (occupational DIY)","overall_risk":"moderate-high","primary_concerns":["Skin/eye irritant: glycol ethers cause dermal irritation and severe eye damage","Ingestion toxicity: metabolic acidosis, CNS depression","Neurotoxicity: high-dose glycol ether exposure affects CNS","Material damage: attacks automotive paint, rubber, and plastics"],"exposure_routes":"dermal (primary), ocular, ingestion"},"exposure":{"routes":["dermal","ingestion","ocular"],"contact_types":["skin_direct","eye_splash","oral_incidental"],"users":["adult"],"duration":"acute","frequency":"periodic","scenarios":["Skin contact during brake service","Eye splash when opening reservoir","Ingestion (accidental or intentional)","Paint/surface damage from spills"],"notes":"DIY mechanics are primary exposure population. Brake fluid is strongly hygroscopic and attacks painted surfaces, rubber, and most plastics."},"consumer_guidance":{"red_flags":[],"green_flags":[],"what_to_ask":[],"alternatives":[{"name":"DOT 5 silicone brake fluid","notes":"Non-hygroscopic, non-corrosive to paint; not compatible with DOT 3/4 systems without full flush"}],"notes":null},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"DOT FMVSS 116","citation":null,"requirements":"Brake fluid must meet DOT performance standards (boiling point, viscosity).","compliance_status":null,"effective_date":null,"enforcing_agency":"NHTSA","penalties":null,"source_ref":null}],"certifications":[],"labeling":{"required_disclosures":["DOT grade","Harmful if swallowed"],"prop65_warning":{"required":null,"chemicals":[],"endpoint":null,"notes":null},"ghs_labeling":{"required":null,"signal_word":"WARNING","pictograms":["exclamation_mark"],"hazard_statements":["Harmful if swallowed","Causes eye irritation"],"notes":null},"hidden_ingredients":{"trade_secret_protected":null,"categories_hidden":[],"estimated_count":null,"known_concerns":null,"notes":null},"notes":null},"recalls":[],"regulatory_gap":null,"notes":null},"lifecycle":{"recyclable":true,"disposal_guidance":"Hazardous waste recycling","hazardous_waste":true,"expected_lifespan":"2-3_years"},"formulation":{"form":"liquid","key_ingredients":[{"hq_id":"hq-c-org-000517","name":"Polyethylene glycol monoethers","role":"base_fluid","concentration_pct":"50-80"},{"hq_id":null,"name":"Triethylene glycol monomethyl ether","role":"co-solvent","concentration_pct":"10-30"},{"hq_id":null,"name":"Borate ester corrosion inhibitors","role":"corrosion_inhibitor","concentration_pct":"5-10"},{"hq_id":null,"name":"Antioxidants","role":"stabilizer","concentration_pct":"1-3"}],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-000517","compound_name":"Polyethylene glycol ethers","role":"base_fluid","typical_concentration":null}],"identifiers":{"common_names":["brake fluid","DOT 3 fluid","DOT 4 fluid","hydraulic brake fluid"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"Generic Mass-Market Brand A","manufacturer":"Consumer Products Corporation","market_position":"mass_market","notable":"Widely available mass-market option"},{"brand":"Generic Mass-Market Brand B","manufacturer":"Consumer Goods Ltd","market_position":"mass_market","notable":"Popular budget alternative"},{"brand":"Premium Brand A","manufacturer":"Premium Consumer Inc","market_position":"premium","notable":"Upscale premium positioning"}],"brand_examples_disclaimer":"Representative branded products of this category. Concerning ingredients listed in materials.concerning[] apply to the category, not necessarily to every named brand. Specific formulations vary by SKU and may have changed since this record was written; consult the brand's current ingredient label before drawing brand-level conclusions.","sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-24"},{"type":"regulation","title":"DOT FMVSS 116","jurisdiction":"USA","id":"src_ffbfe623"},{"id":"fda_efsa_peg400_excipient_2016","type":"regulatory","title":"FDA Inactive Ingredient Database PEG-400 Oral Topical Parenteral; EFSA 2016 ADI 10 mg/kg bw/day E1521; ICH Q3C Residual EO 1,4-Dioxane Limits; PEG Sensitization Anaphylaxis; Renal Accumulation Insufficient; No IARC NTP EPA Carcinogenicity Classification","year":2016,"inherited_from_compound":"hq-c-org-000517"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-24","timestamp":"2026-05-14T01:24:28.755Z"}}