Just as with the aldehydes, esters, and organic acids, you count the carbons, including the one in the cyanide functional group when naming the compounds. Organic cyanides are not as toxic as the ionic bonded cyanide salts; however, they should be treated with respect in terms of toxicity. Acetonitrile is flammable and a dangerous fire risk and toxic by inhalation and skin absorption. The TLV is 40 ppm in air. It has an NFPA 704 listing of flammability 3, health2, and reactivity 0. Isocyanates have a general formula of R-NCO. Isocyanates are name with the radical first radical and ending in the word isocyanate. An example would be to add the methyl radical to the isocyanate functional group, which would yield methyl isocyanate (MIC)