Working with Isocyanates
Isocyanates are one of the leading causes of occupational asthma in the UK. Every year, vehicle paint sprayers develop this life-changing condition. Once they have it even tiny amounts of isocyanate exposure can trigger an attack, which often forces them to leave the profession completely.
Two-pack (2k) paints, coatings and lacquers, are widely used for their durability and finish quality. However, when sprayed, these paints release invisible isocyanate-containing mist that spreads rapidly and can reach dangerous levels within minutes.
The Health and Safety Executive (HSE) is conducting inspections of motor vehicle repair businesses that use isocyanate-containing materials. These inspections focus on ensuring proper health and safety measures are in place. This guidance will help you protect your workers, comply with legal requirements, and prepare for inspections.
Always use proper spray facilities and correct respiratory protective equipment
You must use air-fed breathing apparatus – filtering respirators will not protect you.
Respect clearance times – every time
Your spray booth needs time to clear invisible isocyanate paint mist.
Workers lifting visors too soon is a common mistake.
Monitor exposure levels regularly
Our legal duty under COSHH Regulation 10 requires exposure monitoring.
Biological monitoring through urine testing is HSE and industry’s recommended method.
Published on Monday 26th October 2026