Is TCP (Tricresyl phosphate) safe for dogs and cats?
Low risk for petsDogs are relatively resistant to TOCP compared to humans. Exposure unlikely in typical home environment.
What is tcp (tricresyl phosphate)?
TCP (Tricresyl phosphate) is a organophosphate, plasticizer, flame retardant.
The IUPAC name is tris(methylphenyl) phosphate.
Also known as: TCP, Tricresyl phosphate, tritolyl phosphate, phosphoric acid tricresyl ester.
- IUPAC name
- tris(methylphenyl) phosphate
- CAS number
- 1330-78-5
- Molecular formula
- C21H21O4P
- Molecular weight
- 368.36 g/mol
- SMILES
- O=P(OC1=CC=C(C)C=C1)(OC2=CC=C(C)C=C2)OC3=CC=C(C)C=C3
Risk for dogs
Low riskDogs are relatively resistant to TOCP compared to humans. Exposure unlikely in typical home environment.
While TOCP can cause delayed neuropathy in multiple species, dogs require substantially higher doses than humans to develop symptoms. Typical home exposure is minimal.
Risk for cats
Low riskCats are unlikely to encounter significant TCP exposure in typical home settings.
While cats have reduced capacity for glucuronidation (relevant to some organophosphate metabolism), typical home TCP exposure levels are very low. Industrial or accidental exposure would be the primary concern.
Regulatory consensus
4 regulatory and scientific bodies have classified TCP (Tricresyl phosphate). The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| EU REACH | — | SVHC (Substance of Very High Concern) — tri-ortho isomer | TOCP (CAS 78-30-8) listed as SVHC under REACH. Mixed TCP (1330-78-5) regulated via TOCP content limits. |
| OSHA | — | PEL: 0.1 mg/m³ (skin notation) | OSHA Permissible Exposure Limit with skin designation indicating significant dermal absorption potential |
| ACGIH | — | TLV-TWA: 0.1 mg/m³ (skin notation) | ACGIH Threshold Limit Value — 8-hour time-weighted average |
| EU CLP | — | Repr. 2 (H361), STOT RE 1 (H372 — nervous system) | Classified as suspected reproductive toxicant and confirmed specific target organ toxicant (repeated exposure, nervous system) |
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 tcp (tricresyl phosphate)
- aircraft hydraulic fluid
- jet engine oil (Mobil Jet Oil II and similar)
- aircraft cabin air (during fume events via bleed air system)
- vinyl plastic (as plasticizer)
- flame retardant formulations
- synthetic lubricants
- industrial hydraulic fluids
- lacquers and varnishes (historically)
Safer alternatives
Lower-risk approaches that achieve a similar outcome to TCP (Tricresyl phosphate):
- Tributyl phosphate (TBP)
- Non-organophosphate flame retardants
Frequently asked questions
Is tcp (tricresyl phosphate) safe for pets?
Dogs are relatively resistant to TOCP compared to humans. Exposure unlikely in typical home environment.
What products contain tcp (tricresyl phosphate)?
TCP (Tricresyl phosphate) appears in: aircraft hydraulic fluid; jet engine oil (Mobil Jet Oil II and similar); aircraft cabin air (during fume events via bleed air system).
What should I do if my pet is exposed to tcp (tricresyl phosphate)?
Keep pets away from areas where TCP-containing products are stored or used industrially. Seek veterinary care if product ingestion suspected.
Why do regulators disagree about tcp (tricresyl phosphate)?
TCP (Tricresyl phosphate) has been classified by 4 agencies including EU REACH, OSHA, ACGIH, EU CLP, 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 TCP (Tricresyl phosphate) in the pets app
Look up products containing tcp (tricresyl phosphate), 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 →