cyanic acid cyanate isocyanic acid PMID:19494520 HN=C=O N=C=O PMID:26760716 Beilstein:1616281 HNCO hydrogen isocyanate isocyansaeure PMID:977566 isocyanate CAS:75-13-8 ICA CHNO 43.00581 43.02478 carbimide Gmelin:840 chebi_ontology isozyansaeure isocyanic acid CHEBI:29202 0 OWIKHYCFFJSOEH-UHFFFAOYSA-N oxidoazanediidocarbon Reaxys:1616281 [C(NH)O] InChI=1S/CHNO/c2-1-3/h2H methenamide PMID:26124058 A colourless, volatile, poisonous inorganic compound with the formula HNCO; the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly-found elements in organic chemistry and biology. hydracid one-carbon compound