{"hq_id":"hq-p-hom-000216","name":"Plumbing Solder (Lead-Free Since 1986, Legacy Lead Joints)","category":{"primary":"household","secondary":"plumbing","tags":["plumbing solder","lead-free","1986","Safe Drinking Water Act","legacy","copper pipe","tin"]},"product_tier":"HOM","overall_risk_level":"moderate","description":"Plumbing solder for copper pipe joints: lead solder (50/50 tin-lead) was standard until Safe Drinking Water Act Amendment (1986) banned lead in plumbing solder for potable water systems. Lead-free solder (95/5 tin-antimony, or tin-silver-copper) is now required. However: homes built before 1986 may have lead solder on every joint. Lead from solder dissolves into standing water — especially in acidic (low pH) or soft water. Lead from plumbing solder is the #1 in-home source of lead in drinking water after service line replacement.","synthesis":{"derived_risk_level":"extreme","synthesis_confidence":0.744,"synthesis_method":"compound_composition","context_used":"human_child","context_source":"product_users","exposure_modifier":1.38,"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":"children in pre-1986 homes, infants (formula preparation)","overall_risk":"moderate","primary_concerns":["Pre-1986 homes: every copper joint has lead solder","Lead dissolves into standing water (first-draw highest)","Hot water dissolves more lead than cold — never use hot tap for drinking/cooking","'Lead-free' before 2014: up to 8% lead was permitted"],"exposure_routes":"Oral via drinking water passing through lead-soldered joints"},"exposure":{"routes":["oral"],"contact_types":["oral_direct"],"users":["adult","child"],"duration":"continuous","frequency":"daily","scenarios":["Drinking water from pre-1986 plumbing with lead solder joints","First-draw stagnation water: highest lead concentration","Hot water dissolves more lead than cold (never use hot tap for drinking)","New lead-free solder: trace lead still present (<0.2%)"],"notes":"SDWA 1986: banned lead in solder for potable water. But 'lead-free' until 2014 meant <8% lead; Reduction of Lead in Drinking Water Act (2011, effective 2014) reduced to <0.25% weighted average. Pre-1986 homes: every copper joint is a potential lead source. Flushing cold water 30-60 seconds reduces first-draw lead. NSF 53 filter at kitchen tap removes >99% of lead. Homes built 1986-2014: 'lead-free' solder may contain up to 8% lead."},"consumer_guidance":{"usage_warning":"Pre-1986 home: flush cold water 30-60 sec before drinking. Never use hot tap for drinking or cooking. Install NSF 53 certified filter at kitchen tap. Test water for lead ($30 home test). DIY plumbing: use only lead-free solder marked 'for potable water systems.'","safer_alternatives":["NSF 53 certified filter at kitchen tap (removes >99% lead)","Cold water flushing 30-60 sec before drinking","Professional re-piping with PEX or copper using modern lead-free solder","Point-of-use reverse osmosis at kitchen sink"],"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":"NSF 53 certified filter at kitchen tap","notes":"removes >99% lead"},{"name":"Cold water flushing 30-60 sec before drinking","notes":"Alternative"},{"name":"Professional re-piping with PEX or copper using modern lead-free solder","notes":"Alternative"}]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"Safe Drinking Water Act — Lead Solder Ban (1986/2014)","citation":"42 U.S.C. 300g-6","requirements":"1986: banned lead solder in potable water. 2014: reduced 'lead-free' definition to <0.25% weighted average (was <8%).","compliance_status":null,"effective_date":"1986-06-19","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":"Lead solder: scrap metal recycling. Do not put in regular waste.","hazardous_waste":true,"expected_lifespan":"50+_years"},"formulation":{"form":"varies","key_ingredients":[{"hq_id":"hq-c-ino-000001","name":"Lead (Pb)","role":"legacy_solder","concentration_pct":"50 of pre-1986 solder"}],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-ino-000001","compound_name":null,"role":"legacy_solder","typical_concentration":"50% of pre-1986 solder"}],"identifiers":{"common_names":["plumbing solder (lead-free since 1986, legacy lead joints)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"SC Johnson","manufacturer":"SC Johnson","market_position":"mass_market","notable":"Household product conglomerate"},{"brand":"Clorox","manufacturer":"Clorox","market_position":"mass_market","notable":"Household cleaning market leader"},{"brand":"3M","manufacturer":"3M","market_position":"mass_market","notable":"Home safety and maintenance products"}],"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":"2026-03-25"},{"type":"regulation","title":"Safe Drinking Water Act — Lead Solder Ban (1986/2014) (42 U.S.C. 300g-6)","jurisdiction":"USA","year":1986,"citation":"42 U.S.C. 300g-6","id":"src_f92017f0"},{"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":"2026-05-14T01:27:05.851Z"}}