The risk of adverse health effects from a pesticide chemical is a function of pesticide toxicity and time of exposure. Exposure time determines the dose (amount that enters the body) and toxicity determines the potency of the dose. For pesticides that do not cause cancer, there is a dose below which there will be no ill effect. For pesticides that do not cause cancer, a no effect threshold has been determined for each pesticide. This threshold level is inversely related to the potency (toxicity) of the particular pesticide chemical. For pesticides that have been deemed to cause cancer (carcinogenic) the probability that exposure will result in cancer is related to dose. The greater the exposure, the greater the probability of developing cancer. In each case, risk is directly related to exposure, as exposure determines dose. Exposure can come from air, food and water or from direct contact with skin, but if exposure is low enough, the risk of adverse health effects is nil, regardless of pesticide toxicity.