Isocyanates are a group of chemicals used in the manufacture of polyurethane plastics, synthetic rubbers, foams, paints, varnishes and adhesives. People exposed to isocyanates can develop a range of short term health problems, such as headache, sore eyes, sore throat, difficulty in breathing, and skin irritation. More seriously, isocyanate exposure can lead to long term asthma and dermatitis if individuals become sensitised. Sensitisation is a condition in which breathing or skin conditions can return with increasing severity with any further exposure to the original sensitising agent, or similar substances even at very low exposures.
All isocyanates are hazardous substances and require care in handling.
People exposed to isocyanates at work are at greater risk of developing respiratory problems, such as asthma, if they breathe in isocyanate vapours or droplets of resin spray. They may also experience skin conditions if they have regular skin contact with isocyanates. Here droplets containing isocyanates are the main hazard because they can be inhaled and absorbed by the body. Workplaces where TDI is mixed with resins in the manufacture of foam. Here isocyanate vapours released during mixing and curing are the main hazard.