Sustainable Tire Additives

Regulation of 6PPD, the antioxidant that has protected motor-vehicle tires for more than six decades, has entered its most demanding testing and rule-making phase, sharpening the industry’s focus on safer, more sustainable tire additives.

The U.S. Environmental Protection Agency has issued an advance notice of proposed rulemaking (ANPRM) under Section 6 of the Toxic Substances Control Act covering 6PPD and its transformation product, 6PPD-quinone. The notice gathers information on environmental exposure, persistence and potential alternatives ahead of any future regulatory action.

6PPD, or N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine, is an antiozonant and antioxidant that shields tire rubber against cracking and degradation from ozone, oxygen, thermal stress and mechanical fatigue. Industry representatives note that essentially every motor-vehicle tire on the road today relies on 6PPD-class protection, and that no drop-in commercial substitute offering comparable safety and durability is yet widely available.

The regulatory path began with a 2023 citizen petition from three Pacific Northwest Tribes, which the EPA granted in November 2023, followed by a December 2024 reporting rule requiring 6PPD manufacturers and importers to submit health and safety studies. The agency has also published a draft analytical method for detecting the chemical in surface and stormwater, a prerequisite for any future compliance regime.

That alternative gap is the central focus of a concurrent alternatives analysis under way in California, where regulators have advanced seven candidate substances to the next stage of evaluation. In parallel, tire manufacturers are working to identify and validate replacement additives that preserve performance while lowering environmental impact. Trade bodies have urged regulators to favour staged risk evaluation and alternatives development over abrupt phase-outs, warning that a premature ban could compromise tire safety without a validated substitute in place.

The outcome is being watched closely across the tire, rubber and recycling sectors, since any eventual shift in additive chemistry will ripple through both virgin-material and recovered-material value chains. For recyclers and recovered carbon black producers, the additive debate reinforces the value of circular material pathways: as the industry searches for safer, sustainable additive chemistries, verified recovered material streams — including recovered carbon black produced from end-of-life tire pyrolysis — offer a complementary route to reduce the environmental footprint of the tire value chain.

Learn More:

• Recovered Carbon Black Production
• Tire Pyrolysis Projects
• What Is Pyrolysis?
• Feasibility Studies
• Circular rCB in India

Partner With The KleanTeam for Safer, Circular Tire Materials

Safe. Clean. Profitable. One Proven Partner.

Tire-additive regulation is pushing the industry toward sustainable alternatives, and recovered carbon black from end-of-life tire pyrolysis sits at the centre of that shift. Klean Industries delivers the technology and engineering to turn scrap tires into verified circular materials.

Klean’s Key Advantages:

• ✅ 8 recovered carbon black (rCB) facilities built in India over the past 2 years.
• ✅ Signed LOI to supply 5 more rCB plants in India.
• ✅ Canadian government (DFAITC) recognized Klean for India cleantech and circular-economy trade.
• ✅ KBR added Klean’s proprietary TyreNova tire-pyrolysis technology to its IP portfolio.
• ✅ Klean delivers feasibility studies, turn-key EPC, design and engineering, and pyrolysis/gasification consulting.

Ready to turn regulatory pressure into a recoverable-materials opportunity?

Speak with a Tire Pyrolysis Expert at Klean Industries » GO.