H-3218.1
SUBSTITUTE HOUSE BILL 2421
State of Washington
69th Legislature
2026 Regular Session
By House Environment & Energy (originally sponsored by Representatives Hall, Berry, Parshley, Zahn, Ramel, Pollet, Reed, and Hill)
READ FIRST TIME 02/03/26.
AN ACT Relating to 6PPD and regrettable 6PPD substitutes in tires; reenacting and amending RCW 43.21B.110 and 43.21B.300 ; adding a new chapter to Title 70A RCW; and creating a new section.
BE IT ENACTED BY THE LEGISLATURE OF THE STATE OF WASHINGTON:
NEW SECTION. Sec. 1. (1) The legislature finds that 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) is a chemical commonly used in motor vehicle tires to keep them from cracking and degrading quickly. 6PPD works by moving to the surface of the tire and forming a film that protects the tire. When 6PPD is exposed to oxygen and ozone at the surface of a tire, it forms 6PPD-quinone (2-((4-methylpentan-2-yl)amino)-5-(phenylamino)cyclohexa-2,5-diene-1, 4-dione). As tires are used and degrade, they release 6PPD-quinone as tire wear particles that are washed or deposited into streams, rivers, and other water bodies through stormwater runoff, aerial deposition, and other pathways.
(2) The legislature further finds that 6PPD-quinone is directly linked to urban runoff mortality syndrome, a condition where coho salmon die prior to spawning. 6PPD-quinone is known to be toxic to aquatic species and is the primary causal toxicant for coho salmon.