Pet Safety / Compounds / Endosulfan

Is Endosulfan safe for dogs and cats?

High risk for pets

Dogs are highly susceptible to endosulfan acute neurotoxicity via the same GABA-A receptor antagonism mechanism as other cyclodiene insecticides. Canine LD50 for endosulfan is approximately 35 mg/kg. Dogs in or near endosulfan-treated agricultural areas may be exposed through skin contact with treated vegetation, ingestion of contaminated soil or vegetation, or consumption of contaminated prey. Acute endosulfan toxicosis in dogs presents as hyperactivity, salivation, muscle tremors progressing to tonic-clonic seizures, and hyperthermia. Emergency management involves seizure control (benzodiazepines, phenobarbital), fluid therapy, and temperature management. The continuing use of endosulfan in some countries and the compound's moderate environmental persistence make it a contemporary veterinary concern in regions where the compound is still applied.

What is endosulfan?

The IUPAC name is 1,9,10,11,12,12-hexachloro-4,6-dioxa-5lambda4-thiatricyclo[7.2.1.02,8]dodec-10-ene 5-oxide.

Also known as: 1,9,10,11,12,12-hexachloro-4,6-dioxa-5lambda4-thiatricyclo[7.2.1.02,8]dodec-10-ene 5-oxide, Benzoepin, Thiodan, Thionex.

IUPAC name
1,9,10,11,12,12-hexachloro-4,6-dioxa-5lambda4-thiatricyclo[7.2.1.02,8]dodec-10-ene 5-oxide
CAS number
115-29-7
Molecular formula
C9H6Cl6O3S
Molecular weight
406.9 g/mol
SMILES
C1C2C(COS(=O)O1)C3(C(=C(C2(C3(Cl)Cl)Cl)Cl)Cl)Cl
PubChem CID
3224

Risk for dogs

High risk

Dogs are highly susceptible to endosulfan acute neurotoxicity via the same GABA-A receptor antagonism mechanism as other cyclodiene insecticides. Canine LD50 for endosulfan is approximately 35 mg/kg. Dogs in or near endosulfan-treated agricultural areas may be exposed through skin contact with treated vegetation, ingestion of contaminated soil or vegetation, or consumption of contaminated prey. Acute endosulfan toxicosis in dogs presents as hyperactivity, salivation, muscle tremors progressing to tonic-clonic seizures, and hyperthermia. Emergency management involves seizure control (benzodiazepines, phenobarbital), fluid therapy, and temperature management. The continuing use of endosulfan in some countries and the compound's moderate environmental persistence make it a contemporary veterinary concern in regions where the compound is still applied.

Risk for cats

High risk

Cats' GABA-A antagonist sensitivity, combined with their limited hepatic glucuronidation, makes them particularly susceptible to endosulfan. Exposure routes include contact with treated vegetation in gardens and agricultural areas, grooming of contaminated fur, and consumption of contaminated prey. Cats hunting near treated fields during the spray season are at highest risk. Endosulfan's moderate persistence (endosulfan sulfate persisting longer than parent compound) maintains risk in the environment for weeks after application. Feline endosulfan toxicosis requires emergency management; prognosis depends on dose and time to treatment.

Regulatory consensus

4 regulatory and scientific bodies have classified Endosulfan. The classifications differ — that's the data.

AgencyYearClassificationNotes
UNEPPersistent Organic Pollutant (POP)
EPA CTX / EPA OPPNot Likely to Be Carcinogenic in Humans
EPA CTX / GenetoxGenotoxicity: negative (Ames: negative, 0 positive / 1 negative reports)
EPA CTX / GenetoxGenotoxicity: negative (Ames: negative, 0 positive / 1 negative reports)

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where pets encounter endosulfan

  • Industrial FacilitiesManufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational EnvironmentsFactories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Endosulfan:

  • Physical/mechanical pest control (IPM)
    Trade-offs: More labor-intensive. May not be sufficient for severe infestations.
    Relative cost: 1.2-2×

Frequently asked questions

Is endosulfan safe for pets?

Dogs are highly susceptible to endosulfan acute neurotoxicity via the same GABA-A receptor antagonism mechanism as other cyclodiene insecticides. Canine LD50 for endosulfan is approximately 35 mg/kg. Dogs in or near endosulfan-treated agricultural areas may be exposed through skin contact with treated vegetation, ingestion of contaminated soil or vegetation, or consumption of contaminated prey. Acute endosulfan toxicosis in dogs presents as hyperactivity, salivation, muscle tremors progressing to tonic-clonic seizures, and hyperthermia. Emergency management involves seizure control (benzodiazepines, phenobarbital), fluid therapy, and temperature management. The continuing use of endosulfan in some countries and the compound's moderate environmental persistence make it a contemporary veterinary concern in regions where the compound is still applied.

What products contain endosulfan?

Endosulfan appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

Why do regulators disagree about endosulfan?

Endosulfan has been classified by 4 agencies including UNEP, EPA CTX / EPA OPP, EPA CTX / Genetox, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See Endosulfan in the pets app

Look up products containing endosulfan, compare to alternatives, and explore the full data record.

Open in pets View raw API data

Sources (3)

  1. Stockholm Convention COP5: Endosulfan Added to Annex A (Elimination) with Specific Exemptions — Global Phase-Out Timeline, Agricultural Worker Deaths, Environmental Persistence Assessment (2011) — regulatory
  2. US EPA: Endosulfan Phase-Out Agreement with Makhteshim Agan — Aquatic Life Risk, Worker Safety, Agricultural Worker Poisonings in Developing Countries, Ecological Risk Assessment (2010) — regulatory
  3. Government of Kerala / National Institute of Occupational Health: Health Effects of Endosulfan Aerial Spraying in Kasargod District, Kerala — Congenital Malformations, Neurological Disorders, Epidemiological Investigation (2001) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →