Food was not kept cold enough, hot enough, cooled fast enough, or cooked or reheated to the right temperature. Bacteria grow quickly in the "danger zone" between 41°F and 135°F, which makes this one of the most important food-safety checks.
Toxic substances properly identified, stored, used
In plain English
Cleaning products, pesticides, or other chemicals were stored or labeled in a way that could let them get into food. This is serious because chemical contamination can make people sick quickly.