This Technical Report provides industrial hygienists, employers and workers with a broad overview of isocyanates, their uses in industry, methods of measurement and guidance on choosing the appropriate sampling strategy. While not all issues can be addressed here in detail, this Technical Report discusses areas of concern to alert the industrial hygienist, employer and worker involved with the use of isocyanates to the importance of sampling and the key issues involved in choosing a sampling strategy for their workplace, and directs them to seek further information on the topic(s) of concern.