Get lots of sleep, keep your back straight, and make sure your sleeping position isn't terrible.
A hazardous material is any item or agent ( it can be biological, chemical, radioactive, and any sort of physical object ), that has the potential of harming any biological creature or the environment (by biological we mean humans, animals etc.)
Any substance that is a health hazard is a hazardous material. Here are some examples : chemicals with carcinogents, toxic agents, sensitizers etc.
Answer:
Before you start and when your done with one kind of food and when completely done
Explanation: