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.
Over worked maybe, she has been touring and she didn't eat much so she feels pretty dizzy, she needs to rest and take it slow, she over worked her muscles some how and she needs to take a break<span />