Is 2,4-Toluene diisocyanate safe for dogs and cats?
High risk for petsNot veterinary or professional safety advice, and not a substitute for a veterinarian — consult one about your animal. Full disclaimer →
GHS Danger classification. Dogs lack metabolic pathways to detoxify many synthetic chemicals. Acute lethality risk from accidental ingestion.
What is 2,4-toluene diisocyanate?
The IUPAC name is 2,4-diisocyanato-1-methylbenzene.
Also known as: 2,4-diisocyanato-1-methylbenzene, TOLUENE 2,4-DIISOCYANATE, 2,4-Diisocyanatotoluene, Tolylene-2,4-diisocyanate.
- IUPAC name
- 2,4-diisocyanato-1-methylbenzene
- CAS number
- 584-84-9
- Molecular formula
- C9H6N2O2
- Molecular weight
- 174.16 g/mol
- SMILES
- CC1=CC=C(C=C1N=C=O)N=C=O
- PubChem CID
- 11443
Risk for dogs
High riskGHS Danger classification. Dogs lack metabolic pathways to detoxify many synthetic chemicals. Acute lethality risk from accidental ingestion.
Risk for cats
High riskGHS Danger classification. Cats lack metabolic pathways to detoxify many synthetic chemicals. Acute lethality risk from accidental ingestion.
Regulatory consensus
3 regulatory and scientific bodies have classified 2,4-Toluene diisocyanate. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| EPA CTX / NTP RoC | — | Reasonably Anticipated to be a Human Carcinogen | |
| EPA Genetox (via EPA CTX / Genetox) | — | Genotoxicity: positive (Ames: positive, 5 positive / 5 negative reports) | |
| IARC | 1999 | Group 2B - Possibly carcinogenic to humans (Toluene diisocyanates; IARC Monographs Volumes 39, Sup 7, 71) | IARC List of Classifications row "Toluene diisocyanates" (Group 2B; Volumes 39, Sup 7, 71; 1999): a CLASS evaluation covering the 2,4- isomer by agent name; the list row's CAS column carries the mixture RN 26471-62-5, not 584-84-9 | IARC Monographs Volume 71 (1999), section "Toluene diisocyanates", §1.1.1 Nomenclature: the agent covers commercial mixtures (26471-62-5), 2,4-toluene diisocyanate (584-84-9) and 2,6-toluene diisocyanate (91-08-7); archived at audits/archive/2026-09-10-D750-iarc-mono71-37-toluene-diisocyanates.pdf |
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 2,4-toluene diisocyanate
- Industrial Facilities — Manufacturing plants, Chemical storage
- Consumer Products — Paints, Adhesives, Cleaning products
Safer alternatives
Lower-risk approaches that achieve a similar outcome to 2,4-Toluene diisocyanate:
-
Bio-based polymer alternatives where available
Trade-offs: Performance limitations. End-of-life complexity.Relative cost: 2-5× conventional
Frequently asked questions
Is 2,4-toluene diisocyanate safe for pets?
GHS Danger classification. Dogs lack metabolic pathways to detoxify many synthetic chemicals. Acute lethality risk from accidental ingestion.
What products contain 2,4-toluene diisocyanate?
2,4-Toluene diisocyanate appears in: Manufacturing plants (Industrial facilities); Chemical storage (Industrial facilities); Paints (Consumer products); Adhesives (Consumer products).
Why do regulators disagree about 2,4-toluene diisocyanate?
2,4-Toluene diisocyanate has been classified by 3 agencies including EPA CTX / NTP RoC, EPA CTX / Genetox, IARC, 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 2,4-Toluene diisocyanate in the pets app
Look up products containing 2,4-toluene diisocyanate, compare to alternatives, and explore the full data record.
Open in pets View raw API dataReference 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 →