{"hq_id":"hq-p-pet-000065","name":"Fipronil Flea and Tick Spot-On for Dogs and Cats (Frontline, GABA Antagonist, Bee Toxicity, Environmental Persistence)","category":{"primary":"pet_care","secondary":"flea_tick_topical","tags":["fipronil","Frontline","flea","tick","dog","cat","GABA","phenylpyrazole","bee toxicity","environmental persistence"]},"product_tier":"PET","overall_risk_level":"moderate","description":"Fipronil (brand: Frontline) is a phenylpyrazole insecticide that blocks GABA-gated chloride channels in arthropod nervous systems, providing broad-spectrum flea and tick control for both dogs and cats. Unlike permethrin, fipronil is safe for cats at label doses, making it the standard topical choice for multi-species households. Applied monthly as a spot-on, fipronil distributes across the skin via sebaceous glands within 24 hours. Environmental concerns are significant: fipronil is highly toxic to bees (contact LD50 4.2 ng/bee), persists in soil with a half-life of 125 days, and its degradate fipronil sulfone bioaccumulates in aquatic food chains. The EU restricted fipronil seed treatments in 2013 (alongside neonicotinoids) to protect pollinators, though veterinary topical use remains permitted.","synthesis":{"derived_risk_level":"moderate","synthesis_confidence":0.82,"synthesis_method":"compound_composition","context_used":"human_adult","context_source":"product_users","exposure_modifier":0.85,"vulnerability_escalated":true,"escalation_reason":"Child exposure group","compounds_resolved":1,"compounds_total":1,"synthesis_date":"2026-03-27","synthesis_version":"1.0.0"},"hazard_summary":{"sensitive_populations":"bees and pollinators (contact LD50 4.2 ng/bee), aquatic invertebrates, children (dermal contact with treated pets)","overall_risk":"moderate","primary_concerns":["Extreme bee toxicity — fipronil is among the most toxic insecticides to pollinators","Environmental persistence: soil half-life 125 days; metabolite fipronil sulfone bioaccumulates","Aquatic contamination from pet bathing runoff and direct application wash-off","Photodegradation product fipronil desulfinyl is more toxic than parent compound"],"exposure_routes":"Dermal (topical application on pets; contact transfer to humans). Environmental (soil persistence, aquatic runoff, pollinator exposure)."},"exposure":{"routes":["dermal","ingestion"],"contact_types":["dermal_direct","ingestion_grooming"],"users":["pet_dog","pet_cat","child","adult"],"duration":"chronic","frequency":"monthly","scenarios":["Pet: monthly topical application with dermal absorption","Child: petting treated animals within 24 hours of application","Environment: wash-off and excretion contaminate waterways; highly toxic to bees and aquatic invertebrates","Bathing: premature bathing reduces efficacy; runoff enters sewage system"],"notes":"Fipronil blocks GABA-gated chloride channels (selective for invertebrate GABA receptors vs mammalian). Half-life in soil: 125 days; photodegradation produces fipronil desulfinyl (more toxic than parent). EU restricted agricultural use 2013 (Implementing Regulation 485/2013); veterinary use unaffected. Bee toxicity: contact LD50 4.2 ng/bee (one of the most bee-toxic insecticides). Safe for cats: feline LD50 >500 mg/kg oral."},"consumer_guidance":{"usage_warning":"Apply fipronil spot-on only to dry skin between shoulder blades. Keep children from contacting application site for 24 hours. Do not bathe pets within 48 hours of application. Do not allow treated pets to swim in natural waterways for 48 hours — fipronil is extremely toxic to aquatic life and bees.","safer_alternatives":["Isoxazoline oral preventives (no environmental release from topical application)","Selamectin (Revolution) for combined flea/heartworm protection","Essential oil-based repellents (limited efficacy but lower environmental impact)","Flea combs and indoor environmental management (vacuuming, washing bedding)"]},"regulatory":{"applicable_regulations":[{"jurisdiction":"EU","regulation":"EU Restriction on Fipronil Agricultural Use — Implementing Regulation 781/2013","citation":"Commission Implementing Regulation (EU) No 781/2013 amending Regulation 540/2011; Regulation (EC) No 1107/2009","requirements":"Restricted fipronil seed treatment uses to protect pollinators (alongside neonicotinoid restrictions). Veterinary topical products (Regulation EU 2019/6 on veterinary medicinal products) remain authorized under separate regulatory framework.","compliance_status":null,"effective_date":"2013-12-31","enforcing_agency":"EU Member State competent authorities / EFSA","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":"Dispose of empty applicators in household trash. Do not rinse containers into drains. Fipronil is classified as a marine pollutant for transport purposes.","hazardous_waste":false,"expected_lifespan":"Monthly application; 30-day efficacy period"},"formulation":{"form":"varies","key_ingredients":[],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-000183","compound_name":null,"role":"active_ingredient","typical_concentration":"9.8% w/v in Frontline; distributes via sebaceous glands; soil half-life 125 days"}],"identifiers":{"common_names":["fipronil flea and tick spot-on for dogs and cats (frontline, gaba antagonist, bee toxicity, environmental persistence)"],"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":"2026-05-02T18:29:04.632Z"}}