The risk assessment process offers regulators, registrants, public interest groups and users a means of weighing apparent health and environmental effects of pesticides (herbicides) and other chemicals, and measuring their safety for use. This paper examines three key areas of risk assessment: (1) Maximum Tolerated Dose (MTD), (2) Cancer Classification and Risk Assessment, and (3) Ecological Risk Assessment. The American, European and International approaches in these important areas are compared and discussed in light of the current scientific knowledge.