Establishing Maximum Residue Limits for Pesticides (continued JMPR also reviews existing pesticides on a 1 5-year cycle. Toxicology and Residue Chemistry can be done in different years. Periodic reviews can result in a modification of the MRL or in its deletion if the use is no longer supported by the manufacturer. 2008 examples-fenvalerate, metalaxyl. USDAEstablishing Maximum Residue Limits for Pesticides Limits for Pesticides Pesticides (continued) (continued) ƒ JMPR also reviews existing pesticides on a 15- y y ear c ycle. Toxicology and Residue Chemistry can be done in different years. ƒ Periodic reviews can result in a modification of the MRL or in its deletion if the use is no longer supported by the manufacturer. ƒ 2008 examples —fenvalerate fenvalerate, metalaxyl