Food safety is one of the key areas of focus in public health as it affects every person around the world. When something gets into food that shouldn’t be there it becomes unsafe to consume. This can happen through biological, chemical, and physical contamination. 

Biological contamination occurs when disease-causing bacteria or viruses infect food that is later consumed. The toxins they release often lead to food poisoning and can be very dangerous. Products such as meat, seafood, eggs, and dairy are more vulnerable to bacterial growth and are considered high-risk. Properly storing, cleaning, and cooking these foods at the correct temperature can help reduce the risk of biological contamination. 

Chemical contamination happens when substances like cleaning products, non-food grade plastics, and pesticides get into your food. Additionally,  physical contamination involves foreign objects like hair, pests, various materials, and dirt entering the food

Nowadays, we automatically expect that our eaten goods will be hygienic and only contain the ingredients labeled on the packaging. However, natural produce is not grown in completely sterile conditions, which means that our diet might occasionally include traces of soil, animal hairs, mold, feces, and insects. This has been acknowledged by the US government in the publication of the Defect Levels Handbook which defines acceptable levels of food contamination from sources such as maggots, insect fragments, rodent hairs, and animal feces. Crushed oregano, for example, can contain 300 or more insect bits and about two rodent hairs for every 10 grams.

Environmental pollution, though often invisible, can also find its way into our food. It enters through plants or animals that have been exposed to pollution in the water and soil. For example, water pollution may accumulate and concentrate in fish. In Japan, the release of industrial waste into the sea resulted in locals eating seafood containing mercury and later suffering from the neurological disease Minamata.

When we think of food poisoning, flowers rarely come to mind. Interestingly, a couple of species of rhododendron plants produce harmful toxins in their nectar. Bees collect it and produce honey that can lead to “mad honey disease”, causing symptoms such as hallucinations, nausea, and vomiting.

For this reason, these flowers were indirectly used to fight armies. In 67 BCE, Roman soldiers were deceived into consuming the honey, causing them to disorientate, which led to the deaths of over 1,000 troops. In Turkey, the same “mad honey” is available for purchase at 166 dollars per pound, and it is widely regarded as a long-standing tradition.

A quick look at any ingredients list will likely reveal a few strange substances, and although some might seem unappealing, they may not necessarily be harmful. For example, shellac, commonly used for nail polish, is also employed to add gloss to food, such as apples and candies (listed as additive number 904). Substances like silicon dioxide, known as sand, are often found in everyday items like salt, soup, and coffee creamer to prevent dry components from clumping. Additionally, cellulose, primarily derived from wood pulp, is added to shredded cheese to prevent the strands from sticking together. 

Not all manufacturers disclose chemical additives to the government or consumers. The Food and Drug Administration has introduced a law that considers certain common food ingredients, like vinegar and vegetable oil, generally safe without needing a formal check. Over time, it has become a loophole, allowing manufacturers to decide the safety of their new chemicals in food without informing the FDA. Despite the FDA’s attempts to encourage the industry to voluntarily share all ingredients, people become worried about ensuring food safety in the industry. At this point, it's nearly impossible to determine if common household products do not contain chemicals that could have harmful effects.

Most of these unexpected discoveries in food could be prevented by taking some precautions. Gary Marnum, an instructor at the Marine Institute, advises that the safest thing you can do is to cook your food thoroughly and keep your dry products like flour in a dry environment. Fresh produce should be washed under running water with a good scrub, while items such as rice, grains, and beans can be soaked and cleaned in multiple changes of water. Though it might be challenging to avoid eating some dirt or a few bugs, taking these precautions can help increase your food safety.