Pennsylvania Permit Test 1 Question The minimum size of placards identifying hazardous materials is: Answers Four inches. Six and one-quarter inches. Nine and three-quarter inches. 10 and three-quarter inches. Explanation Hazardous materials placards must be at least 10 and three-quarter inches square. Answer Statistics 23.53 % of our users get this question wrong. This questions is relatively Easy. Pennsylvania Permit Test This questions appears in the following tests: Pennsylvania HazMat ,