Carl Winter: Hi! My name is Carl Winter, I am a spokesperson for the Institute of Food Technologists. I am a Food Toxicologist on the faculty at the University of California, Davis.

Today I'll be discussing food safety issues that pertain to potentially dangerous chemical contaminants in the food supply. In the previous segment, we discussed a little bit about toxicology which is the basic science of poisons. One of the most important principles of toxicology is that the dose makes the poison. In essence, all chemicals are toxic, if the dose of those chemicals is high enough. So it's not the presence or absence of a chemical contaminant in food that determines the potential for harm, but rather the amount of that chemical.

One way to illustrate this is to consider if we have a headache, we might want to take some pain relievers. If we follow the regular dosage, which might be one or two tablets of a pain reliever, hopefully, that will be a low enough dose to relieve our headaches but not enough of a dose to make us sick. If on the other hand, we decided to take the entire contents of that bottle, we might find ourselves in a hospital with an overdose. In both cases, it's the same chemical that we're exposed to, but there's a difference in the dose; the dose makes the poison.

When we talk about exposure to chemical contaminants in the food supply, fortunately, in most cases our exposure to these chemicals is very small. In the next segment, I'll discuss the dose of chemicals that we are exposed to in the food supply.