You’ve heard that toxic chemicals are bad for you, but what exactly is a toxic chemical? Here’s an explanation of what is meant by the term “toxic chemical” as well as examples of common toxic chemicals you may have in your home or encounter in the environment.Labeling a chemical as “toxic” or “non-toxic” is misleading because any compound can be toxic, depending on the route of exposure and the dose. For example, even water is toxic if you drink enough of it. Toxicity depends on other factors besides dose and exposure, including species, age, and gender. For example, humans can eat chocolate, yet it’s toxic to dogs. In a way, all chemicals are toxic. Similarly, there is a minimum dose for nearly all substances below which toxic effects are not seen, called the toxicity endpoint. A chemical can be both necessary for life and toxic. An example is iron. Humans need low doses of iron to make blood cells and perform other biochemical tasks, yet an overdose of iron is deadly. Oxygen is another example.