There are numerous reasons that food could be compromised and become unsafe. By knowing these reasons, it is easier for you to avoid them.
Cleaning agents, pesticides, and other toxic substances must be kept away from food. Fruits and vegetables should be washed thoroughly before use. Canned food must be removed from opened cans and stored in other containers. Do not use rusted pots, pans or cooking utensils.
Germs are too small to see without a microscope. Not all of them are harmful; some are beneficial and useful. We need them to make bread, cheese, wine and sauerkraut. Some are used to manufacture medications, and some are necessary in our body to help with digestion. However some germs are harmful and dangerous. These include bacteria, viruses, molds and parasites. The most dangerous germs are the ones which prefer the foods we like: meat, poultry, fish, eggs, and baked foods with crème fillings. They need moisture and favorable temperatures between 45° F (7° C) and 140° F (60° C) in order to multiply rapidly and provoke food borne illnesses.
Some people have allergies that could be fatal. The most known are tree nuts and shellfish.