|Preferred IUPAC name
3D model (
CompTox Dashboard (EPA)
|Molar mass||268.404 g·mol−1|
|Appearance||brown or violet solid powder|
|Melting point||45 °C (113 °F; 318 K)|
|Boiling point||260 °C (500 °F; 533 K)|
|H302, H317, H360, H410|
|P201, P202, P261, P264, P270, P272, P273, P280, P281, P301+P312, P302+P352, P308+P313, P321, P330, P333+P313, P363, P391, P405, P501|
|Flash point||204 °C (399 °F; 477 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
6PPD is an
p-phenylenediamine (PPD) additives used to protect various rubber materials.
6PPD is prepared by
Despite 6PPD being used in tires since the mid 1960s, this transformation was first identified in 2020,
It is not known why the ozone-oxidised 6PPD is toxic to coho salmon. The
Washington Department of Ecology, Washington State University and the US Tire Manufacturer's Association are working on regulation and education.
- N-Isopropyl-N'-phenyl-1,4-phenylenediamine a related antiozonant
- N,N'-Di-2-butyl-1,4-phenylenediamine - a phenylenediamine based antioxidant used as a fuel additive
- U.S. Tire Manufacturers Association (July 15, 2021). "Statement of Sarah E. Amick Vice President EHS&S and Senior Counsel U.S. Tire Manufacturers Association". Committee on Natural Resources Subcommittee on Oversight and Investigations United States House of Representatives.
Tian, Zhenyu; Zhao, Haoqi; Peter, Katherine T.; Gonzalez, Melissa; Wetzel, Jill; Wu, Christopher; Hu, Ximin; Prat, Jasmine; Mudrock, Emma; Hettinger, Rachel; Cortina, Allan E.; Biswas, Rajshree Ghosh; Kock, Flávio Vinicius Crizóstomo; Soong, Ronald; Jenne, Amy; Du, Bowen; Hou, Fan; He, Huan; Lundeen, Rachel; Gilbreath, Alicia; Sutton, Rebecca; Scholz, Nathaniel L.; Davis, Jay W.; Dodd, Michael C.; Simpson, Andre; McIntyre, Jenifer K. (3 December 2020), "A ubiquitous tire rubber–derived chemical induces acute mortality in coho salmon", S2CID 227281491,
... existing TWP [tire wear particle] loading, leaching, and toxicity assessments are clearly incomplete. ... Accordingly, the human health effects of such exposures merit evaluation. ... It is unlikely that coho salmon are uniquely sensitive ...
- Also an erratum to this paper published in Science vol. 375, No. 6582, 18 Feb 2022 DOI: 10.1126/science.abo5785 reporting the updated toxicity estimates, as referenced below.
- "Pollution from car tires is killing off salmon on US west coast, study finds". The Guardian. 3 December 2020.
- "Scientists solve mystery of mass coho salmon deaths. The killer? A chemical from car tires". Los Angeles Times. 3 December 2020.
- Tian, Zhenyu; Gonzalez, Melissa; Rideout, Craig; Zhao, Hoaqi Nina; Hu, Ximin; Wetzel, Jill; Mudrock, Emma; James, C. Andrew; McIntyre, Jenifer K; Kolodziej, Edward P (11 January 2022), "6PPD-Quinone: Revised Toxicity Assessment and Quantification with a Commercial Standard",
- Lena Beck (17 May 2022). "Your car is killing coho salmon". The Counter.