{"hq_id":"hq-p-out-000042","name":"Pressure-Treated Lumber Deck","category":{"primary":"outdoor","secondary":"construction","tags":["pressure treated","CCA","ACQ","arsenic","copper","deck","playground"]},"product_tier":"OUT","overall_risk_level":"high","description":"Pressure-treated lumber used for outdoor decks, fences, and playground structures. Pre-2004 treatment was CCA (chromated copper arsenate) containing arsenic and chromium VI. Post-2004 residential treatment is ACQ (alkaline copper quaternary) or CA-B (copper azole). CCA-treated wood remains in millions of existing structures. ACQ uses high copper concentrations that leach into soil.","synthesis":{"derived_risk_level":"moderate_to_high","synthesis_confidence":0.858,"synthesis_method":"compound_composition","context_used":"human_child","context_source":"product_users","exposure_modifier":1.05,"vulnerability_escalated":true,"escalation_reason":"Child exposure group","compounds_resolved":3,"compounds_total":3,"synthesis_date":"2026-03-27","synthesis_version":"1.0.0"},"hazard_summary":{"sensitive_populations":"children (playground exposure)","overall_risk":"high","primary_concerns":["Arsenic in CCA-treated wood — IARC Group 1 carcinogen","Chromium VI in CCA — IARC Group 1 carcinogen","Soil contamination beneath treated structures persists for decades"],"exposure_routes":"Dermal contact with treated wood; oral via hand-to-mouth; soil ingestion"},"exposure":{"routes":["dermal","oral"],"contact_types":["skin_prolonged","oral_direct"],"users":["adult","child"],"duration":"hours","frequency":"weekly","scenarios":["Barefoot walking on treated deck (dermal transfer of surface residue)","Children playing on CCA-treated playground equipment (hand-to-mouth transfer)","Soil beneath treated deck accumulating leached chemicals over years"],"notes":"EPA voluntarily phased out CCA for residential use in 2004 but did NOT require removal of existing CCA structures. An estimated 90% of pre-2004 outdoor wood structures are CCA-treated. Arsenic surface residue on CCA wood averages 10-80 ug/100cm2 — above EPA's dislodgeable arsenic risk threshold."},"consumer_guidance":{"usage_warning":"Determine if existing deck is CCA-treated (pre-2004 construction). If CCA: seal annually with penetrating stain, do not sand or saw without respiratory protection, wash hands after contact, do not grow food in soil beneath. New construction: use ACQ/CA-B treated wood or naturally rot-resistant species.","safer_alternatives":["Composite decking (Trex, TimberTech) — no chemical leaching","Naturally rot-resistant wood (cedar, redwood, black locust)","Thermally modified wood (heat treatment, no chemicals)"],"alternatives":[{"name":"Composite decking","notes":"Trex, TimberTech) — no chemical leaching"},{"name":"Naturally rot-resistant wood","notes":"cedar, redwood, black locust"},{"name":"Thermally modified wood","notes":"heat treatment, no chemicals"}],"red_flags":[{"indicator":"Product used in enclosed or poorly ventilated space","meaning":"Chemical exposure concentrations increase dramatically in enclosed spaces.","action":"Use only in well-ventilated outdoor areas as intended."}],"green_flags":[{"indicator":"Third-party safety certification visible on packaging","meaning":"Product has been independently tested to applicable safety standards.","verification":"Look for certification logos (CPSIA, ASTM, EN, NSF, UL, OEKO-TEX)."}],"what_to_ask":[{"question":"What materials is this product made from?","why_it_matters":"Material composition determines chemical exposure potential.","good_answer":"Full material disclosure with known safe materials.","bad_answer":"No material information or unspecified."}]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"EPA FIFRA / TSCA (as applicable)","citation":null,"requirements":"Pesticide registration under FIFRA. Chemical substances under TSCA.","compliance_status":null,"effective_date":null,"enforcing_agency":"EPA","penalties":null,"source_ref":null},{"jurisdiction":"USA -- California","regulation":"California Proposition 65","citation":null,"requirements":"Products containing listed chemicals require warnings.","compliance_status":null,"effective_date":null,"enforcing_agency":"OEHHA","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":"CCA-treated wood is hazardous waste — do not burn. Take to hazardous waste facility. ACQ-treated wood: regular construction waste.","hazardous_waste":true,"expected_lifespan":"10-25_years"},"formulation":{"form":"varies","key_ingredients":[{"hq_id":"hq-c-ino-000002","name":"Arsenic (inorganic)","role":"preservative_historic","concentration_pct":"0.25-0.4 lbs/ft3"},{"hq_id":"hq-c-ino-000043","name":"Hexavalent chromium (Cr(VI))","role":"preservative_historic","concentration_pct":"0.15-0.3"},{"hq_id":"hq-c-ino-000048","name":"Copper nanoparticles (nano-Cu)","role":"preservative_current","concentration_pct":"0.1-0.25 lbs/ft3"}],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-ino-000002","compound_name":null,"role":"preservative_historic","typical_concentration":"0.25-0.4 lbs/ft3"},{"hq_id":"hq-c-ino-000043","compound_name":null,"role":"preservative_historic","typical_concentration":"0.15-0.3%"},{"hq_id":"hq-c-ino-000048","compound_name":null,"role":"preservative_current","typical_concentration":"0.1-0.25 lbs/ft3"}],"identifiers":{"common_names":["pressure-treated lumber deck"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"Skip Hop","manufacturer":"Carter's Inc.","market_position":"mass_market","notable":"Designer play mat brand"},{"brand":"Baby Care","manufacturer":"Baby Care","market_position":"premium","notable":"Large foam play mats"},{"brand":"Lollaland","manufacturer":"Lollaland","market_position":"premium","notable":"Non-toxic play surface"}],"sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-25"},{"type":"regulation","title":"EPA FIFRA / TSCA (as applicable)","jurisdiction":"USA","id":"src_70a4d79c"},{"type":"regulation","title":"California Proposition 65","jurisdiction":"USA -- California","id":"src_fe1d5adc"},{"id":"iarc_100c","type":"regulatory","title":"IARC Monographs Volume 100C: Arsenic and Arsenic Compounds","year":2012,"inherited_from_compound":"hq-c-ino-000002"},{"id":"epa_arsenic_iris","type":"regulatory","title":"US EPA IRIS Assessment: Arsenic, Inorganic","year":1998,"inherited_from_compound":"hq-c-ino-000002"},{"id":"iarc_chromium_v100c_2012","type":"regulatory","title":"IARC Monographs Volume 100C: Arsenic, Metals, Fibres and Dusts — Chromium (VI) Compounds Group 1 (Lung Cancer, Nasal/Sinus Cancer), Nickel Compounds Group 1, Beryllium Group 1 (2012)","year":2012,"inherited_from_compound":"hq-c-ino-000043"},{"id":"epa_mcl_inorganics","type":"regulatory","title":"US EPA: National Primary Drinking Water Regulations — Inorganic Chemicals (40 CFR 141.62); Total Chromium MCL 100 μg/L, Barium MCL 2 mg/L, Uranium MCL 30 μg/L, Selenium MCL 50 μg/L, Manganese SMCL 50 μg/L","year":1992,"inherited_from_compound":"hq-c-ino-000043"},{"id":"scenihr_nano_2015","type":"regulatory","title":"EU Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR): Final Opinion on the Safety of Nanomaterials in Food — Nano-CeO2 as diesel fuel additive (Eolys); biopersistent lung particle; NTP 2-year inhalation bioassay lung tumors at high dose; redox-active antioxidant/pro-oxidant dual behavior (2015)","year":2015,"inherited_from_compound":"hq-c-ino-000048"},{"id":"niosh_nano_cu_2012","type":"regulatory","title":"NIOSH Current Intelligence Bulletin 63: Occupational Exposure to Titanium Dioxide — Nano-Cu comparative toxicology; copper nanoparticle inhalation toxicology; REL 1 mg/m³ copper dust/mist; nano-specific engineering controls guidance (2012)","year":2012,"inherited_from_compound":"hq-c-ino-000048"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-25","timestamp":"2026-05-01T14:27:01.326Z"}}