How often do hazardous materials employees need to be trained? Do you currently have car insurance? Insurance is mandatory to drive in Ohio Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question How often do hazardous materials employees need to be trained? Answers At least once a week At least once every three years At least one every 10 years Explanation Employees who work with hazardous materials must be trained and tested at least once every three years. This questions appears in the following tests: Alaska Tank Connecticut HazMat Iowa HazMat Iowa HazMat Kentucky HazMat Missouri HazMat Nevada HazMat New Mexico HazMat Oregon HazMat South Dakota Tank South Dakota Tank Tennessee HazMat Utah HazMat Vermont HazMat