what is the un classification for fertilizer grade ammonium nitrate?

Question

trying to answer a question as why fertilizer grade ammonium nitrate is not classified as an explosive, and what is it's classification.

Answer 1

Classification depends on who is asking. This one sounds like a Controlled Substance classification - the answer lies somewhere in the volatility/toxicity/flammability index. You should be able to find most substances in an OSHA manual.