313c signifies that although not mentioned by name and CAS number, this chemical is reportable under one or more from the EPCRA part 313 chemical types. Hydrolysis (the interaction with water) causes the soaked solid to release trace quantities of hydrogen cyanide. A standard description of your odor of hydrogen https://potassium-cyanide-solutio30344.rimmablog.com/29159894/the-fact-about-potassium-cyanide-or-sodium-cyanide-that-no-one-is-suggesting