6PPD-quinone in water and air: safety profile
Low risk(People-specific data is limited; this page draws from human adult context.) Minimal direct human exposure pathway. Primary concern is environmental, not direct human toxicity.
What is 6ppd-quinone?
6PPD-quinone is a transformation product, quinone, environmental contaminant.
The IUPAC name is 2-anilino-5-(4-methylpentan-2-ylamino)cyclohexa-2,5-diene-1,4-dione.
Also known as: 6PPD-Q, 2-anilino-5-(4-methylpentan-2-ylamino)cyclohexa-2,5-diene-1,4-dione, N-(1,3-dimethylbutyl)-N'-phenyl-p-benzoquinone diimine oxidation product.
- IUPAC name
- 2-anilino-5-(4-methylpentan-2-ylamino)cyclohexa-2,5-diene-1,4-dione
- CAS number
- 2754428-18-5
- Molecular formula
- C18H22N2O2
- Molecular weight
- 298.4 g/mol
- SMILES
- CC(CC(C)C)NC1=CC(=O)C(=CC1=O)NC2=CC=CC=C2
- PubChem CID
- 154926030
Risk for people
Low riskMinimal direct human exposure pathway. Primary concern is environmental, not direct human toxicity.
6PPD-quinone is an environmental transformation product of tire rubber antioxidant 6PPD. Human exposure is primarily indirect via contaminated water or dust. No significant direct toxicity data in humans. The compound's extreme aquatic toxicity does not translate to equivalent mammalian risk due to different metabolic pathways.
Regulatory consensus
4 regulatory and scientific bodies have classified 6PPD-quinone. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| Washington State Legislature | 2024 | Banned in tires (SB 5931) | First-in-nation ban on 6PPD in tires, effective 2030. Requires manufacturers to find safer alternatives. |
| US EPA | 2023 | Risk assessment initiated | EPA initiated formal risk evaluation of 6PPD and 6PPD-quinone under TSCA |
| California DTSC | 2023 | Under evaluation | California studying restrictions on 6PPD in tires under Safer Consumer Products program |
| EU REACH | — | Under consideration for restriction | European Chemicals Agency considering REACH restriction on 6PPD |
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 you encounter 6ppd-quinone
- tire wear particles
- road runoff / stormwater
- urban waterways and streams
- treated wastewater effluent
- urban sediments
- crumb rubber (playgrounds, artificial turf)
Safer alternatives
Lower-risk approaches that achieve a similar outcome to 6PPD-quinone:
- Alternative tire antioxidants under development
Frequently asked questions
What products contain 6ppd-quinone?
6PPD-quinone appears in: tire wear particles; road runoff / stormwater; urban waterways and streams.
Why do regulators disagree about 6ppd-quinone?
6PPD-quinone has been classified by 4 agencies including Washington State Legislature, US EPA, California DTSC, EU REACH, 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 6PPD-quinone in the water app
Look up products containing 6ppd-quinone, compare to alternatives, and explore the full data record.
Open in water View raw API dataSources (3)
- — expert_curation
- (2021) — peer_reviewed
- (2024) — 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 →