Attributes . UL: Class I, Division 1, Groups A, B, C, and D: T4 - Class 1 Zone 0 AEx da ia IIC T4 Ga1. CSA: Class I, Division 1, Groups A, B, C, and D: T4 C22.2 No. 152 applies only to %LEL thermo-catalytic reading. ATEX: Ex da ia IIC T4 Ga, Equipment Group and Category II 1G ATEX: Ex da ia IIC T4 Ga, Equipment Group and Category II 1G. IECEx: Ex da ia IIC T4 Ga . Names