Final answer:
The Environmental Protection Agency (EPA) is responsible for determining the safety of new pesticides, setting tolerance levels for pesticides, and ensuring safe pesticide residues in food.
Step-by-step explanation:
The agency responsible for determining the safety of new pesticides and setting tolerance levels for all pesticides and their residues in food is the Environmental Protection Agency (EPA). The EPA administers the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which governs the registration, distribution, sale, and use of pesticides in the U.S. The EPA's regulatory actions ensure that pesticides used in the United States, as well as the pesticide residues in food, do not pose any harmful effects to humans or the environment when used according to label directions.