The wrong time to learn about chemical reactions is when you have a spill or accidentally mix incompatible chemicals. Some chemicals, when combined with others, will release poisonous gases or explode violently. How to know which chemicals should never be mixed or even stored near others? Read and understand Section 10: Stability and Reactivity of the chemical’s Safety Data Sheet. For a quick overview of stability and reactivity properties download the Center for Chemical Process Safety’s publications:
Reactive chemistry incidents can happen anywhere!
Dangerous chemical reactions at home!