{"hq_id":"hq-p-out-000085","name":"Residential Pesticide Lawn Treatment — 2,4-D and Glyphosate Herbicide Exposure in Home Landscapes","category":{"primary":"outdoor_environment","secondary":"lawn_pesticide","tags":["2,4-D","glyphosate","herbicide","lawn treatment","Roundup","weed killer","residential","children","pets","drift","runoff"]},"product_tier":"OUT","overall_risk_level":"moderate","description":"Residential lawn herbicide treatments — primarily 2,4-D (the most widely used herbicide in North America, found in Weed B Gon, Trimec, and most 'weed and feed' products) and glyphosate (Roundup, the world's highest-volume herbicide) — expose household members and pets through post-application contact with treated grass, spray drift, tracked-in residues, and contaminated runoff into waterways. 2,4-D is a chlorophenoxy auxin-mimic herbicide classified by IARC as Group 2B (possibly carcinogenic); it is detected on treated lawns for 1-3 days after application and transfers to children playing on grass, with studies showing 2,4-D residues on children's hands and in household dust after lawn treatment. Glyphosate, classified by IARC as Group 2A (probably carcinogenic) based on sufficient evidence of genotoxicity and limited evidence of non-Hodgkin lymphoma in epidemiological studies, is detectable in urine of 80% of Americans (CDC NHANES data), with lawn and garden use as a significant contributor to non-occupational exposure. Pets — particularly dogs — are at elevated risk: epidemiological studies show a 2-fold increase in canine malignant lymphoma in households using 2,4-D lawn products (Hayes et al., 1991). Re-entry intervals recommended on product labels (24-48 hours) are frequently ignored by homeowners.","synthesis":{"derived_risk_level":"moderate_to_high","synthesis_confidence":0.85,"synthesis_method":"compound_composition","context_used":"human_child","context_source":"product_users","exposure_modifier":1,"vulnerability_escalated":true,"escalation_reason":"Child exposure group","compounds_resolved":2,"compounds_total":2,"synthesis_date":"2026-03-27","synthesis_version":"1.0.0"},"hazard_summary":{"sensitive_populations":"children playing on treated lawns (highest contact and hand-to-mouth transfer), dogs (2x malignant lymphoma risk from 2,4-D), pregnant women (endocrine disruption concerns), individuals with non-Hodgkin lymphoma risk factors","overall_risk":"moderate","primary_concerns":["2,4-D lawn treatment associated with 2-fold increase in canine malignant lymphoma","Glyphosate classified IARC Group 2A (probably carcinogenic) — detected in 80% of Americans' urine","Children playing on treated lawns within 24 hours have detectable herbicide residues on hands","Re-entry intervals on labels (24-48 hours) are widely ignored by homeowners"],"exposure_routes":"Dermal (direct skin contact with treated grass — barefoot children, pets rolling on lawns). Ingestion (hand-to-mouth for children; grooming for pets). Inhalation (spray drift during application and volatilization from treated surfaces)."},"exposure":{"routes":["dermal","ingestion","inhalation"],"contact_types":["dermal_direct","ingestion_hand_to_mouth","inhalation_drift"],"users":["child","adult","pet_dog"],"duration":"chronic","frequency":"seasonal_repeated","scenarios":["Child: plays barefoot on 2,4-D-treated lawn within 24 hours of application; hand-to-mouth transfer from grass contact","Dog: walks on and rolls in treated grass; ingests residues through grooming; associated 2x increase in malignant lymphoma","Adult: applies glyphosate to garden beds without protective equipment; dermal and inhalation exposure during spraying","Neighbor: spray drift from lawn treatment enters adjacent property through air and runoff"],"notes":"2,4-D: CAS 94-75-7; IARC Group 2B (2015). US annual use: 25-30 million lbs on home lawns (EPA). Lawn surface residues: detectable for 1-3 days post-application. Canadian study (Curwin et al., 2005): 2,4-D detected on 100% of children's hands after playing on treated lawns. Canine lymphoma: Hayes et al. (1991, JNCI): OR 2.0 for dogs in households using 2,4-D. Glyphosate: CAS 1071-83-6; IARC Group 2A (2015). Global annual production: ~800,000 metric tons. CDC NHANES (2013-2014): glyphosate detected in 80% of urine samples. $11 billion Bayer/Monsanto Roundup settlement (2020) for non-Hodgkin lymphoma claims. EPA re-evaluation (2020): concluded glyphosate 'not likely to be carcinogenic' — contradicting IARC."},"consumer_guidance":{"usage_warning":"Observe re-entry intervals strictly: keep children and pets off treated lawns for at least 24-48 hours after herbicide application, or until the product has dried and been watered in. Apply on calm, windless days to minimize drift. Wear protective gloves and long sleeves during application. Never apply near vegetable gardens, play areas, or water features. Wash children's hands and pets' paws after any lawn contact during the treatment season.","safer_alternatives":["Organic lawn care: overseeding with competitive grass varieties to crowd out weeds","Corn gluten meal as a pre-emergent natural herbicide (does not contain glyphosate)","Manual weeding and targeted spot treatment instead of broadcast application","White clover lawns (nitrogen-fixing, no herbicide needed, pollinator-friendly)","Accepting a diversity of lawn plants rather than pursuing monoculture turf"]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"EPA Herbicide Registration and Re-entry Interval Requirements; IARC Cancer Classifications","citation":"40 CFR 156; EPA Glyphosate Interim Decision (2020); IARC Monographs Vol. 112 (2015)","requirements":"EPA requires re-entry interval labeling on all residential herbicide products. 2,4-D: EPA registered under FIFRA; label requires 24-hour re-entry interval for treated lawns. Glyphosate: EPA concluded 'not likely to be carcinogenic' (2020), contradicting IARC Group 2A classification (2015). No federal ban on residential glyphosate or 2,4-D use. Some municipalities restrict cosmetic pesticide use on lawns (Montgomery County, MD; various Canadian provinces).","compliance_status":null,"effective_date":null,"enforcing_agency":"EPA Office of Pesticide Programs; state pesticide regulatory agencies","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":"Dispose of empty herbicide containers per label instructions — triple rinse and recycle where accepted. Never pour unused herbicide into storm drains, ditches, or waterways.","hazardous_waste":true,"expected_lifespan":"Seasonal application (2-4 treatments per year); glyphosate soil half-life 2-197 days depending on conditions"},"formulation":{"form":"varies","key_ingredients":[],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-000125","compound_name":null,"role":"active_ingredient","typical_concentration":"2,4-D in weed-and-feed products; IARC Group 2B; lawn residues persist 1-3 days; canine lymphoma OR 2.0"},{"hq_id":"hq-c-org-000001","compound_name":null,"role":"active_ingredient","typical_concentration":"glyphosate (Roundup); IARC Group 2A; detected in urine of 80% of Americans (CDC NHANES)"}],"identifiers":{"common_names":["residential pesticide lawn treatment — 2,4-d and glyphosate herbicide exposure in home landscapes"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[],"sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-26"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-26","timestamp":"2026-05-01T14:25:08.770Z"}}