Is Diazinon safe for dogs and cats?
High risk for petsDiazinon is highly toxic to dogs; a significant number of canine fatalities occurred before the 2004 residential ban. Dogs have access to treated lawns, golf course grass, and agricultural areas; grooming after walking on treated surfaces is a high-risk exposure route. Clinical signs: hypersalivation, miosis, muscle fasciculations, seizures, respiratory failure. Treatment: atropine sulfate + pralidoxime (2-PAM). Delayed absorption from skin means clinical signs can be delayed 6–12 hours. Historically marketed as pet flea products but withdrawn due to safety concerns.
What is diazinon?
The IUPAC name is diethoxy-(6-methyl-2-propan-2-ylpyrimidin-4-yl)oxy-sulfanylidene-lambda5-phosphane.
Also known as: diethoxy-(6-methyl-2-propan-2-ylpyrimidin-4-yl)oxy-sulfanylidene-lambda5-phosphane, Dimpylate, Oleodiazinon, Neocidol.
- IUPAC name
- diethoxy-(6-methyl-2-propan-2-ylpyrimidin-4-yl)oxy-sulfanylidene-lambda5-phosphane
- CAS number
- 333-41-5
- Molecular formula
- C12H21N2O3PS
- Molecular weight
- 304.35 g/mol
- SMILES
- CCOP(=S)(OCC)OC1=NC(=NC(=C1)C)C(C)C
- PubChem CID
- 3017
Risk for dogs
High riskDiazinon is highly toxic to dogs; a significant number of canine fatalities occurred before the 2004 residential ban. Dogs have access to treated lawns, golf course grass, and agricultural areas; grooming after walking on treated surfaces is a high-risk exposure route. Clinical signs: hypersalivation, miosis, muscle fasciculations, seizures, respiratory failure. Treatment: atropine sulfate + pralidoxime (2-PAM). Delayed absorption from skin means clinical signs can be delayed 6–12 hours. Historically marketed as pet flea products but withdrawn due to safety concerns.
Risk for cats
High riskCats are highly sensitive to diazinon due to limited hepatic glucuronidation and CYP450 capacity, making diazoxon detoxification slower. Diazinon pet products (collars, dips) for cats caused fatalities; these were withdrawn from the market. Secondary exposure from dogs treated with diazinon or from contaminated environments (rodent control bait stations containing diazinon) remain risk scenarios. LD50 in cats is substantially lower than in dogs or rats. ASPCA APCC classifies diazinon as a major toxin of concern for cats.
Regulatory consensus
8 regulatory and scientific bodies have classified Diazinon. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | 2015 | Group 2A (probably carcinogenic to humans) | IARC Monograph 112 (2015), same volume as malathion. Limited evidence in humans for non-Hodgkin lymphoma and lung cancer; sufficient evidence in experimental animals. EPA banned residential uses in the US effective 2004 due to bird and wildlife kills; agricultural use continues. |
| EPA CTX / IARC | — | Group 2A - Probably carcinogenic to humans | |
| EPA CTX / EPA OPP | — | Not Likely to Be Carcinogenic in Humans | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: negative, 2 positive / 6 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: negative (Ames: negative, 2 positive / 6 negative reports) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Not classified (score: low) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Not classified (score: low) | |
| EPA CTX / Skin-Eye | — | Skin Sensitization: Category 1 (score: high) |
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 diazinon
- Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
- Occupational Environments — Factories, Warehouses, Transportation vehicles
Safer alternatives
Lower-risk approaches that achieve a similar outcome to Diazinon:
-
Physical/mechanical pest control (IPM)
Trade-offs: More labor-intensive. May not be sufficient for severe infestations.Relative cost: Variable; lower long-term
Frequently asked questions
Is diazinon safe for pets?
Diazinon is highly toxic to dogs; a significant number of canine fatalities occurred before the 2004 residential ban. Dogs have access to treated lawns, golf course grass, and agricultural areas; grooming after walking on treated surfaces is a high-risk exposure route. Clinical signs: hypersalivation, miosis, muscle fasciculations, seizures, respiratory failure. Treatment: atropine sulfate + pralidoxime (2-PAM). Delayed absorption from skin means clinical signs can be delayed 6–12 hours. Historically marketed as pet flea products but withdrawn due to safety concerns.
What products contain diazinon?
Diazinon appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).
Why do regulators disagree about diazinon?
Diazinon has been classified by 8 agencies including IARC, EPA CTX / IARC, 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 Diazinon in the pets app
Look up products containing diazinon, compare to alternatives, and explore the full data record.
Open in pets View raw API dataSources (3)
- IARC Monographs Volume 112: Malathion and Diazinon (2015) — regulatory
- US EPA Reregistration Eligibility Decision (RED) for Diazinon (2004) — regulatory
- ASPCA Animal Poison Control Center: Organophosphate and Carbamate Toxicosis in Companion Animals (2018) — report
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 →