UK Launches Landmark Review of Tyre Additives for Environmental Hazards

On 18 July 2025, the UK Environment Agency initiated a major chemical risk screening targeting additives used in tyres, a proactive move to address the environmental impact of tyre wear particles (TWPs).

The agency assessed 61 substances for potential ecological harm based on environmental hazards, usage volumes, and predicted exposure levels.

Why Tyre Chemicals Are Under Scrutiny

Tyres are made from synthetic and natural rubbers blended with numerous additives that enhance performance and durability. However, as tyres degrade, they shed microplastic-like particles, which can release hazardous chemicals into water, soil, and air—posing long-term risks to ecosystems.

Key Findings from the Screening

The Environment Agency used a prioritization model focusing on:

• Environmental hazard
• Tonnage used
• Predicted environmental concentrations

Substance risk categories:

• 14 substances: “Of concern”
• 29 substances: “Potential concern”
• 14 substances: “Lower concern”
• 4 substances: Insufficient data for assessment

Out of these, 20 substances have been shortlisted for further risk assessments, including transformation products already known for their toxicity.

High-Priority Chemicals Identified

Several chemical groups stand out due to their ecological risk:

• Phenylenediamines (e.g., 6PPD, 6PPD-quinone)
• Benzothiazoles
• Phthalates

Of particular concern is 6PPD-quinone, linked to fish mortality in salmon and already under international scrutiny.

Modeling results suggest freshwater sediments are the most vulnerable, where these additives may accumulate and harm aquatic life.

Implications for Industry and UK REACH

Although no immediate restrictions have been enacted under UK REACH, the findings send a strong regulatory signal. Manufacturers and downstream users should be prepared for future risk management measures.

Recommended Industry Actions

• Audit use of flagged chemicals (e.g., 6PPD, MBTS, DCBS, IPPD)
• Monitor updates from DEFRA and the Environment Agency
• Explore safer substitutes for high-risk additives
• Enhance supply chain transparency for chemical tracking

Next Steps in UK Chemical Regulation

The UK government plans to:

• Conduct detailed risk assessments of the 20 flagged substances
• Increase environmental monitoring, especially in sediment
• Evaluate group-level regulatory actions for similar chemicals (e.g., phenylenediamines)

These efforts support broader UK strategies to address microplastic pollution and emerging chemical risks.

Environmental Protection Moving Forward

This is a significant stride in the UK’s mission to manage chemical pollutants from consumer products. With thousands of tonnes of tyre wear particles entering the environment annually, the hazard screening represents a critical early-warning tool.

Stakeholders in the tyre, chemical, and environmental sectors are urged to remain engaged and responsive to ongoing regulatory developments.

Reference: Hazard Screening and UK Risk Prioritisation for Tyre Additives

 

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