COSHH Regulations 2026: What Has Changed and What Employers Need to Do Now

The Control of Substances Hazardous to Health Regulations 2002 (COSHH) remain the primary legal framework for managing risks from hazardous substances in UK workplaces. However, the HSE has issued updated Workplace Exposure Limits (WELs) and revised guidance that requires many employers to review and update their COSHH assessments in 2026.

What Are Workplace Exposure Limits?

WELs are concentrations of hazardous substances in workplace air, averaged over a specified time period, that must not be exceeded. The HSE publishes WELs in EH40/2005 (Workplace Exposure Limits), which is updated periodically to reflect new scientific evidence on health effects.

Key Changes in 2026

The 2026 update to EH40 introduces revised WELs for several commonly used substances, including:

• Silica (respirable crystalline): WEL reduced to 0.05 mg/m³ (8-hour TWA) — tighter controls required in stone masonry, construction, and manufacturing
• Wood dust (hardwood): WEL remains at 3 mg/m³ but new guidance on measurement methodology
• Isocyanates: Updated short-term exposure limit with new monitoring requirements
• Diesel engine exhaust emissions: New WEL of 0.05 mg/m³ (as elemental carbon)

"Employers must ensure their COSHH assessments reflect the latest WELs and that control measures are adequate to prevent exposures exceeding these limits." — HSE COSHH Team

What Employers Must Do

Any employer whose workers may be exposed to substances covered by the updated WELs must:

1. Review existing COSHH assessments to check whether current controls remain adequate
2. Commission air monitoring where there is uncertainty about exposure levels
3. Implement additional engineering controls, PPE, or work practice changes where required
4. Provide updated training to workers and supervisors on the revised risks and controls
5. Maintain records of assessments, monitoring results, and health surveillance

Penalties for Non-Compliance

Failure to comply with COSHH regulations can result in HSE enforcement action, including Improvement Notices, Prohibition Notices, and prosecution. Courts have imposed substantial fines on employers where workers have developed occupational diseases such as occupational asthma, silicosis, or dermatitis as a result of inadequate COSHH management.