Kalmar "isocyonic acid" tana nufin wani sinadari mai suna HNCO. Yana da wani fili mara tsayayye kuma mai saurin amsawa wanda ake amfani dashi da farko wajen samar da kumfa na polyurethane, robobi, da elastomers. Isocyanic acid na iya samuwa ta hanyar amsawar cyanic acid (HOCN) tare da amine ko ta hanyar bazuwar thermal na cyanates. Ruwa ne marar launi wanda yake da ƙamshi mai ƙamshi kuma yana da guba sosai. Isocyanic acid zai iya amsawa da ruwa don samar da carbon dioxide da ammonia.