Conversation so far:
what is the chemical in abc fire extinguishers
Monoammonium phosphate, ABC Dry Chemical, ABE Powder, tri-class, or multi-purpose dry chemical is a dry chemical extinguishing agent used on class A, class B, and class C fires.
can you tell me more about the dry chemical ABC extinguishing agent
Monoammonium phosphate, ABC Dry Chemical, ABE Powder, tri-class, or multi-purpose dry chemical is a dry chemical extinguishing agent used on class A, class B, and class C fires.

Question: how is the agent used
Self-contained rewrite: how is the dry chemical ABC extinguishing agent used