{"hq_id":"hq-p-out-000061","name":"Deck Stain and Wood Preservative (Copper Naphthenate, Legacy Pentachlorophenol)","category":{"primary":"outdoor","secondary":"construction","tags":["deck stain","wood preservative","copper naphthenate","pentachlorophenol","CCA","creosote","outdoor wood"]},"product_tier":"OUT","overall_risk_level":"low","description":"Outdoor wood preservatives and deck stains: modern options include copper naphthenate (green-tinted), zinc naphthenate (clear), and water-based acrylic stains. Legacy preservatives: pentachlorophenol (penta — EPA cancelled residential use 2022, IARC Group 1), creosote (EPA restricted to industrial, IARC Group 2A), and CCA (chromated copper arsenate — phased out for residential 2004). Modern deck stains are primarily aesthetic with UV protection; preservative function is secondary for above-ground wood.","synthesis":{"derived_risk_level":"moderate","synthesis_confidence":0.82,"synthesis_method":"compound_composition","context_used":"human_adult","context_source":"product_users","exposure_modifier":0.77,"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":"applicators, children on freshly treated deck","overall_risk":"low","primary_concerns":["VOC inhalation during application (oil-based highest)","Legacy penta/creosote: IARC Group 1/2A (cancelled/restricted)","Children: wait 48-72 hours after application before deck use","Do not use treated wood for food-contact (garden beds, cutting boards)"],"exposure_routes":"Inhalation during application; dermal contact with wet stain"},"exposure":{"routes":["dermal","inhalation"],"contact_types":["skin_brief","inhalation"],"users":["adult"],"duration":"hours","frequency":"rarely","scenarios":["Applying deck stain: dermal + inhalation during 4-8 hour project","Copper naphthenate: greenish tint, low mammalian toxicity, effective preservative","Legacy penta/creosote: EPA cancelled or restricted for residential","Children playing on recently stained deck (48-72 hour cure before use)"],"notes":"Modern deck stain safety: water-based acrylics have lowest VOC. Oil-based (linseed, tung) have moderate VOC but natural chemistry. Copper naphthenate: EPA-registered wood preservative, low mammalian toxicity, effective against rot and insects. Pentachlorophenol: EPA cancelled ALL uses effective 2024 after decades of IARC Group 1 classification. Do not treat wood that will contact food (garden beds — use untreated cedar or composite instead)."},"consumer_guidance":{"usage_warning":"Choose water-based deck stain (lowest VOC). Apply with ventilation — wear organic vapor respirator for oil-based. Wait 48-72 hours before children use freshly stained deck. Do not use pressure-treated wood for raised garden beds growing food. Copper naphthenate is lowest-toxicity preservative for ground-contact wood.","safer_alternatives":["Water-based acrylic deck stain (lowest VOC)","Naturally rot-resistant wood (cedar, redwood) without preservative","Composite decking (zero chemical treatment, zero maintenance)","Linseed oil-based stain (natural chemistry, moderate VOC)"],"red_flags":[{"indicator":"Working without ventilation or respiratory protection","meaning":"Chemical exposure at hobby level can cause occupational-grade health effects.","action":"Use ventilation and PPE appropriate to the specific hazard."}],"green_flags":[{"indicator":"Using appropriate PPE and ventilation for the specific task","meaning":"Exposure controlled to safe levels.","verification":"Match PPE to specific hazard (N95 for dust, organic vapor for solvents, supplied air for isocyanate)."}],"what_to_ask":[{"question":"What are the specific chemical hazards of this hobby material?","why_it_matters":"Hobby exposures lack occupational protections but cause the same health effects.","good_answer":"SDS available, specific PPE identified, ventilation plan in place.","bad_answer":"No hazard awareness or PPE use."}],"alternatives":[{"name":"Water-based acrylic deck stain","notes":"lowest VOC"},{"name":"Naturally rot-resistant wood","notes":"cedar, redwood) without preservative"},{"name":"Composite decking","notes":"zero chemical treatment, zero maintenance"}]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"EPA Pentachlorophenol Cancellation (2022/2024)","citation":"EPA-HQ-OPP-2021-0263","requirements":"EPA cancelled ALL pentachlorophenol uses effective February 2024. Phase-out period for remaining stock.","compliance_status":null,"effective_date":"2024-02-01","enforcing_agency":"EPA","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":true,"disposal_guidance":"Leftover stain: HHW facility. Empty cans: dry and recycle.","hazardous_waste":false,"expected_lifespan":"1-3_years"},"formulation":{"form":"varies","key_ingredients":[{"hq_id":"hq-c-ino-000048","name":"Copper nanoparticles (nano-Cu)","role":"preservative_active","concentration_pct":"0.5-2"},{"hq_id":"hq-c-org-000011","name":"Formaldehyde","role":"stain_VOC","concentration_pct":"trace"}],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-ino-000048","compound_name":null,"role":"preservative_active","typical_concentration":"0.5-2%"},{"hq_id":"hq-c-org-000011","compound_name":null,"role":"stain_VOC","typical_concentration":"trace"}],"identifiers":{"common_names":["deck stain and wood preservative (copper naphthenate, legacy pentachlorophenol)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"ScottsMiracle-Gro","manufacturer":"ScottsMiracle-Gro","market_position":"mass_market","notable":"Lawn and garden leader"},{"brand":"Husqvarna","manufacturer":"Husqvarna","market_position":"premium","notable":"Outdoor power and garden equipment"},{"brand":"DeWalt","manufacturer":"Stanley Black & Decker","market_position":"mass_market","notable":"Outdoor power tools"}],"sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-25"},{"type":"regulation","title":"EPA Pentachlorophenol Cancellation (2022/2024) (EPA-HQ-OPP-2021-0263)","jurisdiction":"USA","year":2024,"citation":"EPA-HQ-OPP-2021-0263","id":"src_30a5f528"},{"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"},{"id":"iarc_100f_form","type":"regulatory","title":"IARC Monographs Volume 100F: Formaldehyde","year":2012,"inherited_from_compound":"hq-c-org-000011"},{"id":"epa_form_iris","type":"regulatory","title":"US EPA IRIS Assessment: Formaldehyde (draft)","year":2010,"inherited_from_compound":"hq-c-org-000011"},{"type":"regulatory","title":"US Environmental Protection Agency (EPA)","jurisdiction":"USA","id":"src_defdd418","extraction":"description_reference"},{"type":"monograph","title":"International Agency for Research on Cancer (IARC)","jurisdiction":"International","id":"src_d9ebbaf2","extraction":"description_reference"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-25","timestamp":"2026-05-01T14:21:08.762Z"}}