Isosianat adalah gugus fungsi dengan rumus kimia R–N=C=O. Senyawa organik yang mempunyai 2 gugus isosianat disebut diisosianat. Diisosianat diproduksi bersama dengan poliol untuk produksi poliuretana, sebuah polimer.

Isosianat adalah elektrofil dan mereka reaktif terhadap berbagai macam nukleofil termasuk alkohol, amina, dan bahkan air. Reaksi isosianat dengan alkohol menghasilkan ikatan uretana:^[1]

ROH + R'NCO → ROC(O)N(H)R' (R dan R' adalah gugus alkil atau aril)

• NIOSH Safety and Health Topic: Isocyanates, from the website of the National Institute for Occupational Safety and Health (NIOSH)
• Health and Safety Executive, website of the UK Health and Safety Executive, useful search terms on this site — isocyanates, MVR, asthma
• [1] International Isocyanate Institute
• http://www.actsafe.ca/wp-content/uploads/resources/pdf/Isocyanates.pdf Diarsipkan 2016-03-09 di Wayback Machine.
• Isocyanates – Measurement Methodology, Exposure and Effects Isocyanates in Working Life Workshop Article (1999)
• Health and Safety Executive, Guidance Note (EH16) Isocyanates: Toxic Hazards and Precautions (1984)
• The Society of the Plastics Industry – Technical Bulletin AX119 MDI-Based Polyurethane
• Foam Systems: Guidelines for Safe Handling and Disposal (1993)
• An occupational hygiene assessment of the use and control of isocyanates in the UK by Hilary A Cowie et al. HSE Research Report RR311/2005. Prepared by the Institute of Occupational Medicine for the Health and Safety Executive
• Air Sampling Isocyanates