Here are some comments and additional Learning Goals from ToxTutor Topic 1.

1. Physical Agents. For this course, we do not deal with physical agents, such as radiation. As environmental engineers and scientists we are primarily concerned with chemicals in the environment. (We'll define that use of the term "chemical" later.)

2.  "Toxicant, toxin, poison, toxic agent, toxic substance, and toxic chemical" You have just learned that all chemicals are harmful - it depends on the dose. Here you only need two terms to keep the instructor happy. One is "xenobiotic," usually in the term "xenobiotic chemical," which means some chemical that is not a nutrient or AND is not usually and purposefully consumed by humans. (Alcohol and other recreational drugs are not xenobiotics by that definition, but toxicity refers to the harm of a particular chemical at a particular dose or exposure, not what name we call it.) The other term is "toxin." That term is limited to harmful chemicals of plant or animal origin. Never use the term "toxin" unless you are specifically talking about snakes or poison ivy or such. {Please.}

3. No new learning goals.