Isocyanate Compounds – Potential for Occupational Health Effects (2022)


This paper was compiled to give guidance on the assessment, evaluation and control of occupational exposure to Isocyanate compounds, with an emphasis on recommending a health‐based occupational exposure limit (OEL). The current Safe Work Australia (SWA) workplace exposure standard (WES) and current international OELs are discussed and the possible health effects examined.



Key messages:

Activities such as hot wire cutting foams, welding through polyurethane pipe lagging, high temperature bonding using polyurethane sealants and hot removal of varnishes are activities that may lead to inhalation exposure to isocyanates.  Sanding of isocyanate containing materials such as paints, foams and plastics may also result in inhalation exposure from dust particles.

The toxicology of isocyanate compounds is similar with the critical effects being asthma due to sensitisation and irritation of the skin, mucous membranes, eyes and respiratory tract.  There is also the potential for both irritant and allergic contact dermatitis.

SWA (2019) state that the recommended TWA WES of 0.0001 mg NCO/m3 (0.1 µg NCO/m3) is quantifiable through available sampling and analysis techniques.  However, isocyanates are considered by occupational hygienists to be one of the most challenging chemicals to sample and analyse.

This AIOH Position Paper provides as a number of recommendations to address the challenges of assessment of isocyanate exposures.