Do not allow any food containers to become contaminated with photo chemicals. They can react with some plastics and metals and be carried through a wash process.

Selenium is the worst of the lot above. A bad smell is not an indication of toxic nature. Cyanide smells like almonds and Phosgene smells like fresh cut grass, but both are deadly. The smell of fixer is probably either ammonia or sulfite depending on pH. Neither is very poisonous in the amount you might inhale, but rather are more bothersome.

At worst you might have an allergy to one of these chemicals, so always wear rubber gloves.