313c implies that although not listed by name and CAS number, this chemical is reportable under a number of of your EPCRA part 313 chemical groups. Hydrolysis (the interaction with water) causes the damp solid to launch trace quantities of hydrogen cyanide. A normal description with the scent of hydrogen https://potassium-cyanide-acid-or79146.tokka-blog.com/29853631/the-potassium-cyanide-hazard-symbol-diaries