This standard specifies requirements for the construction and testing of intrinsically safe apparatus intended for use in an explosive dust atmosphere and for associated apparatus that is intended for connection to intrinsically safe circuits which enter such atmospheres.

This standard supplements the general requirements of ANSI/ISA-61241-0: except as indicated in Table A. Where a requirement of this standard conflicts with a requirement of ANSI/ISA-61241-0 the requirements of this standard shall take precedence.

NOTE Intrinsically safe and associated intrinsically safe apparatus utilized in systems should meet the requirements of ANSI/ISA-RP12.06.01.

If associated apparatus is protected by a type of protection listed in ANSI/ISA-61241-0 or ANSI/ISA-60079-0 then the requirements of that method of protection together with the relevant standards, ISA-61241-X or ANSI/ISA-60079-X, also apply to the associated apparatus. The list of exclusions in Table A is directly applicable to associated apparatus intended for use in situations where there is no explosive dust atmosphere and in other circumstances should be used in combination with the requirements of the other methods of protection.

This standard is applicable to electrical apparatus in which the electrical circuits themselves are incapable of causing an explosion in the surrounding explosive dust atmosphere. In other circumstances, associated apparatus should be used in combination with the requirements of the other methods of protection listed in ANSI/ISA-61241-0.