{"hq_id":"hq-p-out-000057","name":"Tire Wear Particles and 6PPD-Quinone (Coho Salmon Lethality)","category":{"primary":"outdoor","secondary":"transportation","tags":["tire wear","6PPD","6PPD-quinone","coho salmon","stormwater","microplastic","rubber"]},"product_tier":"OUT","overall_risk_level":"moderate_to_high","description":"Tire rubber contains 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) as an antioxidant/antiozonant. When 6PPD reacts with ground-level ozone, it forms 6PPD-quinone — a transformation product lethal to coho salmon at concentrations as low as 0.8 μg/L. Discovered in 2020 (Tian et al., Science). Tire wear generates 6 million tons of particles globally per year. Urban stormwater carries 6PPD-quinone from roads into salmon streams. No alternative antiozonant has been identified that doesn't form toxic transformation products.","synthesis":{"derived_risk_level":"moderate","synthesis_confidence":0.82,"synthesis_method":"compound_composition","context_used":"human_adult","context_source":"product_users","exposure_modifier":0.977,"vulnerability_escalated":false,"escalation_reason":null,"compounds_resolved":2,"compounds_total":2,"synthesis_date":"2026-03-27","synthesis_version":"1.0.0"},"hazard_summary":{"sensitive_populations":"coho salmon (lethal at <1 μg/L), freshwater ecosystems","overall_risk":"moderate_to_high","primary_concerns":["6PPD-quinone lethal to coho salmon at 0.8 μg/L (Tian et al. 2020, Science)","Caused decades of unexplained 'urban runoff mortality syndrome'","6 million tons tire wear particles generated globally per year","No alternative antiozonant identified — no simple substitution"],"exposure_routes":"Environmental (stormwater to salmon streams); human exposure significance unclear"},"exposure":{"routes":["oral","dermal"],"contact_types":["oral_direct","skin_brief"],"users":["adult"],"duration":"minutes","frequency":"daily","scenarios":["6PPD-quinone in stormwater killing coho salmon at <1 μg/L","Tire wear generating 6 million tons particles/year globally","Playground crumb rubber containing 6PPD (same source as tire wear)","Human exposure via road dust inhalation and drinking water (significance unclear)"],"notes":"Tian et al. 2020 (Science): identified 6PPD-quinone as the cause of decades-unexplained 'urban runoff mortality syndrome' in coho salmon (40-90% pre-spawn mortality in urban streams). No known alternative antiozonant for tires. Washington State proposed 6PPD restrictions. Bioretention (rain gardens) and stormwater treatment can reduce 6PPD-quinone before it reaches streams. Human health effects of 6PPD-quinone are unstudied."},"consumer_guidance":{"usage_warning":"Consumer action limited — 6PPD is in virtually all tires. Support stormwater treatment infrastructure (bioretention, rain gardens). Reduce driving when practical. Support research into alternative tire antiozonants. Advocate for stormwater treatment before discharge to salmon streams.","safer_alternatives":["Support bioretention/rain garden infrastructure (filters stormwater)","Reduced driving (lower tire wear contribution)","Research into alternative tire antiozonants (industry responsibility)","Permeable pavement for driveways (reduces runoff velocity)"],"red_flags":[{"indicator":"Product causing documented ecological damage","meaning":"Consumer choice directly impacts environmental health.","action":"Choose verified lower-impact alternatives."}],"green_flags":[{"indicator":"Third-party environmental certification or verified lower impact","meaning":"Product evaluated for ecological footprint.","verification":"Check for relevant environmental certifications."}],"what_to_ask":[{"question":"What is the environmental impact of this product beyond my personal use?","why_it_matters":"Consumer products aggregate to ecosystem-level effects.","good_answer":"Documented lower-impact formulation with environmental testing.","bad_answer":"No environmental impact assessment."}],"alternatives":[{"name":"Support bioretention/rain garden infrastructure","notes":"filters stormwater"},{"name":"Reduced driving","notes":"lower tire wear contribution"},{"name":"Research into alternative tire antiozonants","notes":"industry responsibility"}]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA -- Washington","regulation":"Washington State 6PPD investigation","citation":"WA DOE","requirements":"Washington DOE investigating 6PPD restrictions and stormwater treatment requirements for salmon-bearing streams.","compliance_status":null,"effective_date":null,"enforcing_agency":"WA DOE","penalties":null,"source_ref":null}],"certifications":[],"labeling":{"required_disclosures":[],"prop65_warning":{"required":null,"chemicals":[],"endpoint":null,"notes":null},"ghs_labeling":{"required":null,"signal_word":null,"pictograms":[],"hazard_statements":[],"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":false,"disposal_guidance":"Tire wear particles cannot be recovered from road surface.","hazardous_waste":false,"expected_lifespan":"varies"},"formulation":{"form":"varies","key_ingredients":[{"hq_id":"hq-c-org-000029","name":"Benzo[a]pyrene","role":"tire_component","concentration_pct":"trace"},{"hq_id":"hq-c-ino-000001","name":"Lead (Pb)","role":"tire_contaminant","concentration_pct":"trace"}],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-000029","compound_name":null,"role":"tire_component","typical_concentration":"trace"},{"hq_id":"hq-c-ino-000001","compound_name":null,"role":"tire_contaminant","typical_concentration":"trace"}],"identifiers":{"common_names":["tire wear particles and 6ppd-quinone (coho salmon lethality)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"Dyson Pure","manufacturer":"Dyson","market_position":"premium","notable":"HEPA air purifier with filtration"},{"brand":"Levoit","manufacturer":"Vesync","market_position":"mass_market","notable":"Popular affordable HEPA air purifier"},{"brand":"Honeywell","manufacturer":"Honeywell","market_position":"mass_market","notable":"Established air purifier brand"}],"sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-25"},{"type":"regulation","title":"Washington State 6PPD investigation (WA DOE)","jurisdiction":"USA -- Washington","citation":"WA DOE","id":"src_60e4047c"},{"id":"iarc_100f_bap","type":"regulatory","title":"IARC Monographs Volume 100F: Benzo[a]pyrene — Chemical Agents and Related Occupations","year":2012,"inherited_from_compound":"hq-c-org-000029"},{"id":"epa_bap_iris","type":"regulatory","title":"US EPA IRIS: Benzo[a]pyrene — Toxicological Review (Final)","year":2017,"inherited_from_compound":"hq-c-org-000029"},{"id":"src_001","type":"cdc","title":"CDC - Lead Poisoning Prevention","url":"https://www.cdc.gov/lead-prevention/","accessed":"2026-01-13","relevance":"Blood lead reference values, no safe level doctrine","inherited_from_compound":"hq-c-ino-000001"},{"id":"src_002","type":"who","title":"WHO - Lead Poisoning Fact Sheet","url":"https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health","year":2024,"accessed":"2026-01-13","relevance":"Global burden statistics, health effects","inherited_from_compound":"hq-c-ino-000001"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-25","timestamp":"2026-05-01T14:27:15.941Z"}}