Chemical agent and Reducer

Chemical agent noun - An agent that produces chemical reactions.

Reducer and chemical agent are semantically related. In some cases you can replace term "Reducer" with "Chemical agent", this terms are similar.

Reducer noun - A substance capable of bringing about the reduction of another substance as it itself is oxidized; used in photography to lessen the density of a negative or print by oxidizing some of the loose silver.

Chemical agent and reducer are semantically related. Sometimes you can use "Chemical agent" instead a noun "Reducer".