{"hq_id":"hq-p-hom-000012","name":"Residential lawn and garden pesticides","category":{"primary":"household","secondary":"lawn and garden","tags":["lawn pesticide","weed killer","insecticide","herbicide","2,4-D","glyphosate","lawn chemicals","Roundup","chlorpyrifos","permethrin lawn","lawn fertilizer pesticide"]},"product_tier":"HOM","overall_risk_level":"high","description":"Consumer-grade herbicides, insecticides, fungicides, and combination products sold for residential lawn, garden, and ornamental plant use. This category spans herbicides (Roundup/glyphosate, 2,4-D, triclopyr), insecticides (organophosphates, pyrethroids, neonicotinoids), and combination 'weed and feed' fertilizer-pesticide products. Residential pesticide use is a primary source of pesticide tracking-in contamination in homes (via shoes and pets) and a significant source of pesticide exposure for children playing on treated lawns. The transfer of pesticide residues from lawn to indoor carpet has been measured for chlorpyrifos, 2,4-D, and pyrethroid insecticides.","synthesis":{"derived_risk_level":"moderate","synthesis_confidence":0.713,"synthesis_method":"compound_composition","context_used":"human_child","context_source":"product_users","exposure_modifier":1.2,"vulnerability_escalated":true,"escalation_reason":"Child exposure group","compounds_resolved":4,"compounds_total":4,"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","overall_risk":"high","primary_concerns":["Carcinogenicity concern (high): Glyphosate Glyphosate is IARC Group 2A based on non-Hodgkin lymphoma evidence in agricultural worker studies. 2,4-D is a chlorophenoxy herbicide associated with non-Hodgkin lymphoma in agricultural epidemiological studies. Pyrethroids are highly toxic to aquatic invertebrates and fish at concentrations generated by residential use runoff — lethal concentrations for aquatic invertebrates are in the ng/L range."],"exposure_routes":"inhalation, brief skin contact, ingestion"},"exposure":{"routes":["dermal","inhalation"],"contact_types":["inhalation","skin_brief","ingestion"],"users":["adult","child","pregnant","dog","cat"],"duration":"hours","frequency":"occasional","scenarios":["Incidental mouthing or hand-to-mouth transfer by children","Exposure during pregnancy with potential fetal transfer"],"notes":"Application exposure is the highest-concentration event (spray drift, skin contact during application). Post-application tracking-in is the mechanism for ongoing indoor exposure — studies document pesticide tracking into carpet for days after lawn application. Children playing on treated lawns have dermal contact with pesticide residues. Pets are at high risk — they walk through treated grass and groom their paws and fur, ingesting whatever is on the grass surface. Pets sleeping on treated grass or in the home after lawn treatment have measurably higher pesticide body burdens."},"consumer_guidance":{"red_flags":[{"indicator":"Children or pets allowed on lawn within 24–48 hours of pesticide application","meaning":"Pesticide residues on grass are at peak concentration immediately after application and decline as volatilization, photodegradation, and weathering occur. Allowing children and pets on recently treated lawns creates peak exposure.","action":"Post re-entry interval per label. For children under 5 and pregnant women, observe a minimum 48-hour re-entry interval. For cats, avoid permethrin-treated lawns entirely."},{"indicator":"Shoes worn indoors from lawn that was recently treated","meaning":"Lawn pesticide residues are carried indoors on shoe soles. Studies have documented 2,4-D, glyphosate, and pyrethroid insecticides in indoor carpet dust at significantly higher concentrations in homes where outdoor pesticides are used and shoes are worn indoors.","action":"Remove shoes at door. Use this practice year-round, not only after pesticide application."},{"indicator":"Mixing or applying pesticides without PPE (gloves, eye protection, long sleeves)","meaning":"Pesticide concentrate handling creates the highest human exposure scenario. Dermal absorption during concentrate mixing is significantly higher than spray exposure during application.","action":"Wear chemical-resistant gloves, eye protection, and long sleeves/pants during all pesticide mixing and application. Read and follow label PPE requirements — the label is the law under FIFRA."}],"green_flags":[{"indicator":"OMRI Listed organic product (Organic Materials Review Institute)","meaning":"OMRI listing verifies that the active ingredient meets USDA National Organic Program standards. These products typically use botanical or mineral actives (iron-based herbicides, kaolin clay) with lower persistence and toxicity profiles.","verification":"OMRI product database at omri.org."},{"indicator":"No-pesticide lawn care commitment — 'organic lawn care' service","meaning":"Professional organic lawn care services use IPM approaches (compost topdressing, overseeding, targeted spot treatment) that achieve acceptable aesthetics without broad synthetic pesticide use.","verification":"Ask specifically: what active pesticide ingredients do you apply? What is the annual pesticide input per square foot?"}],"what_to_ask":[{"question":"What are the active ingredients in this lawn pesticide product, and what are the re-entry intervals?","why_it_matters":"Active ingredient identity determines the specific toxicology concern (organophosphate vs. pyrethroid vs. herbicide class). Re-entry interval is the legally specified minimum time before humans (especially children) should return to treated areas.","good_answer":"Active ingredient disclosed; re-entry interval specific to children and pregnant individuals (stricter than general 'when dry'); IPM recommendation for non-chemical alternatives.","bad_answer":"Unlabeled active ingredient; no re-entry interval specified; 'safe when dry' without supporting data."}],"alternatives":[{"name":"Integrated Pest Management (IPM)","notes":"Combines monitoring, cultural practices, and targeted treatments to reduce chemical use"},{"name":"Neem oil or insecticidal soap","notes":"Lower toxicity botanical products effective for many common garden pests"},{"name":"Manual removal and habitat modification","notes":"Hand-picking pests and improving soil health reduce chemical dependency"}],"notes":null},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"EPA FIFRA — Federal Insecticide, Fungicide, and Rodenticide Act","citation":null,"requirements":"All pesticides must be EPA-registered for specific uses. The label is the legal document — users are legally required to follow label instructions for application rate, PPE, and re-entry intervals. EPA registration requires efficacy and safety data but the data requirements have gaps documented by the OIG.","compliance_status":null,"effective_date":null,"enforcing_agency":null,"penalties":null,"source_ref":"src_001"},{"jurisdiction":"USA (Multiple states)","regulation":"State pesticide notification ordinances — lawn posting requirements","citation":null,"requirements":"Several states and municipalities require lawn pesticide notification (posting signs) when commercial applications are made, allowing neighbors and passersby to avoid exposure. These requirements vary significantly by jurisdiction.","compliance_status":null,"effective_date":null,"enforcing_agency":null,"penalties":null,"source_ref":"src_002"}],"certifications":[{"name":"CPSC General Safety","issuer":"CPSC","standard":"Consumer Product Safety Act","scope":"General consumer product safety requirements"}],"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":null,"disposal_guidance":"Varies by material; check local recycling guidelines","hazardous_waste":false,"expected_lifespan":"1-3_years"},"formulation":{"form":"liquid","key_ingredients":[{"hq_id":null,"name":"Active ingredient (varies by product)","role":"active_ingredient","concentration_pct":"10-50"},{"hq_id":null,"name":"Water or mineral oil","role":"carrier","concentration_pct":"40-80"},{"hq_id":null,"name":"Emulsifier","role":"surfactant","concentration_pct":"5-10"},{"hq_id":null,"name":"Adjuvant","role":"additive","concentration_pct":"trace"}],"certifications":[]},"materials":{"common":[{"material_id":null,"material_name":"Herbicide active ingredient (glyphosate, 2,4-D, triclopyr)","component":"active pesticidal ingredient","prevalence":"very_common","notes":"Residential herbicides are dominated by: glyphosate (Roundup and generics — most widely used herbicide globally), 2,4-D (chlorophenoxy herbicide, component of Agent Orange), and triclopyr. Glyphosate is IARC Group 2A (probable carcinogen); EPA classifies glyphosate as 'not likely' to be carcinogenic — one of the largest regulatory science disagreements in contemporary pesticide regulation. 2,4-D is associated with non-Hodgkin lymphoma in epidemiological studies."},{"material_id":null,"material_name":"Organophosphate insecticide (malathion, chlorpyrifos — legacy) / pyrethroid (permethrin, bifenthrin)","component":"active pesticidal ingredient","prevalence":"very_common","notes":"Residential insecticides use pyrethroids (permethrin, bifenthrin, cypermethrin) as the dominant class — EPA-registered and considered lower-hazard than organophosphates for mammals. However, pyrethroids are extremely toxic to aquatic invertebrates and fish at sub-ppb concentrations. Chlorpyrifos (organophosphate, developmental neurotoxicant) was EPA-registered for residential use until 2021 residential use cancellation; it persists in older lawn care products and is still widely used in agriculture."}],"concerning":[{"material_id":null,"material_name":"Glyphosate (Roundup herbicide)","concern":"Glyphosate is IARC Group 2A based on non-Hodgkin lymphoma evidence in agricultural worker studies. The IARC vs. EPA classification disagreement is ongoing — Roundup's manufacturer Bayer (Monsanto) has paid $11 billion in settlements to tens of thousands of plaintiffs claiming glyphosate caused their non-Hodgkin lymphoma, without admitting liability. Residential use on lawns creates exposure for children playing on treated surfaces and tracking-in of residues to carpet and indoor surfaces.","compounds_of_concern":["hq-c-org-000001"],"source_refs":["src_001"]},{"material_id":null,"material_name":"2,4-Dichlorophenoxyacetic acid (2,4-D)","concern":"2,4-D is a chlorophenoxy herbicide associated with non-Hodgkin lymphoma in agricultural epidemiological studies. It is absorbed dermally, inhaled as spray drift, and tracked indoors from treated lawns. 2,4-D is widely detected in US children's urine — residential lawn use is a primary source. The IARC Group 2B (possible carcinogen) classification is more conservative than EPA's assessment.","compounds_of_concern":["hq-c-org-000017","hq-c-org-000018"],"source_refs":["src_002","src_003"]},{"material_id":null,"material_name":"Pyrethroid insecticides (permethrin, bifenthrin) — aquatic toxicity","concern":"Pyrethroids are highly toxic to aquatic invertebrates and fish at concentrations generated by residential use runoff — lethal concentrations for aquatic invertebrates are in the ng/L range. Permethrin is also toxic to cats — grooming after contact with permethrin-treated surfaces can be lethal. Human exposure during application and from treated lawn contact is lower hazard for adults but children and pets have disproportionate lawn surface contact.","compounds_of_concern":["hq-c-org-000024"],"source_refs":["src_004"]}],"preferred":[{"material_id":null,"material_name":"Integrated Pest Management (IPM) approach — mechanical and cultural controls first","why_preferred":"IPM prioritizes mechanical weed removal, proper mowing height and irrigation (which prevents many weed and disease problems), and biological controls before chemical intervention. Significantly reduces chemical lawn pesticide use. Effective for most residential lawn management situations.","tradeoffs":"More labor intensive; may not achieve the weed-free aesthetic of chemical lawn management; requires learning curve."},{"material_id":null,"material_name":"Herbicide: corn gluten meal (pre-emergent) or vinegar/citric acid (contact) alternatives","why_preferred":"Corn gluten meal is a natural pre-emergent herbicide (inhibits germination) with no pesticide residue concerns. High-concentration acetic acid (vinegar) kills broadleaf weeds on contact. Neither bioaccumulates or creates the tracking-in contamination risk of synthetic herbicides.","tradeoffs":"Less potent than synthetic herbicides; not registered as EPA pesticides (so no efficacy guarantee); vinegar kills all contacted vegetation including lawn grass."}]},"compound_composition":[{"hq_id":"hq-c-org-000001","compound_name":"Glyphosate","role":"compound_of_concern","typical_concentration":null},{"hq_id":"hq-c-org-000017","compound_name":"Chlorpyrifos","role":"compound_of_concern","typical_concentration":null},{"hq_id":"hq-c-org-000018","compound_name":"Atrazine","role":"compound_of_concern","typical_concentration":null},{"hq_id":"hq-c-org-000024","compound_name":"Permethrin","role":"compound_of_concern","typical_concentration":null}],"identifiers":{"common_names":["residential lawn and garden pesticides","residential lawn","garden pesticides","residential lawn and garden pesticide"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"Generic Mass-Market Brand A","manufacturer":"Consumer Products Corporation","market_position":"mass_market","notable":"Widely available mass-market option"},{"brand":"Generic Mass-Market Brand B","manufacturer":"Consumer Goods Ltd","market_position":"mass_market","notable":"Popular budget alternative"},{"brand":"Premium Brand A","manufacturer":"Premium Consumer Inc","market_position":"premium","notable":"Upscale premium positioning"},{"brand":"Professional Brand","manufacturer":"Professional Products Co","market_position":"professional","notable":"Professional/salon-grade option"},{"brand":"Specialty Eco-Brand","manufacturer":"Natural Products Ltd","market_position":"premium","notable":"Sustainable/natural product line"}],"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":[{"id":"src_001","type":"iarc","title":"IARC Monograph 112 — Glyphosate (Group 2A evaluation, 2015)","url":"https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Some-Organophosphate-Insecticides-And-Herbicides-2017","accessed":"2026-03-08","year":2015,"notes":"IARC Working Group evaluation of glyphosate as Group 2A; basis for subsequent litigation and regulatory reviews globally"},{"id":"src_002","type":"journal","title":"2,4-D in children's urine — residential lawn pesticide use as primary source","url":"https://doi.org/10.1289/ehp.9726","accessed":"2026-03-08","year":2007,"notes":"Epidemiological study associating residential lawn herbicide use with 2,4-D urinary metabolites in children; tracking-in mechanism confirmed"},{"id":"src_003","type":"journal","title":"Pesticide tracking-in from treated lawns — indoor carpet contamination","url":"https://doi.org/10.1289/ehp.95103252","accessed":"2026-03-08","year":1995,"notes":"Classic study documenting lawn pesticide (2,4-D, chlorpyrifos) tracking into carpet; carpet dust concentrations significantly higher than lawn surface post-application"},{"id":"src_004","type":"epa","title":"EPA — Pyrethroid insecticides: ecological risks and residential use","url":"https://www.epa.gov/ingredients-used-pesticide-products/pyrethrins-and-pyrethroids","accessed":"2026-03-08","year":2022,"notes":"EPA assessment of pyrethroid aquatic toxicity; residential runoff impacts on aquatic ecosystems"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-25","timestamp":"2026-05-14T01:28:12.520Z"}}