(3) petroleum products comprise the following classes:(a) Class 1: liquid having a flash point below 37.8 °C determined according to the method provided by ASTM D56, Standard Test Method for Flash Point by Tag Closed Cup Tester, published by the American Society for Testing and Materials International;
(b) Class 2: liquid having a flash point equal to or above 37.8 °C but below 60 °C determined according to the method provided by ASTM D93, Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester, published by the American Society for Testing and Materials International;
(c) Class 3: liquid having a flash point equal to or above 60 °C determined according to the method provided by ASTM D93, Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester, published by the American Society for Testing and Materials International.