We have designed a circuit to lower a 12 Volt power source to 1.25 Volts with a current limit of, I think, 30mA. The location is Class 1 Division 1 Group D is there any place I can find the information of what is considered intrically safe for this location.
The general US domestic Standard is ANSI/UL 913, Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous (Classified) Locations. Also see ANSI/ISA RP 12.06.01-2002, Wiring Methods for Hazardous (Classified) Locations Instrumentation ? Part 1: Intrinsic Safety and read Article 504 very carefully. Your design will require third party certification.