Portable electric equipment must not be used in a hazardous location described in subpart 111.105 of this chapter except:

(a) Self-contained, battery-fed, explosion-proof lamps approved by Underwriters Laboratories Inc., Factory Mutual Research Corporation, or other independent laboratory recognized by the Commandant, for use in a Class I, Division 1 location for the electrical group classification of the cargo;

(b) Intrinsically safe equipment approved by Underwriters Laboratories Inc., Factory Mutual Research Corporation, or other independent laboratory recognized by the Commandant, for use in a Class I, Division 1 location for the electrical group classification of the cargo; and

(c) Any electrical equipment, if:

(1) The hazardous location is:

(i) Enclosed; and

(ii) Gas free;

(2) The adjacent compartments are:

(i) Gas free;

(ii) Inerted;

(iii) Filled with water;

(iv) Filled with Grade E liquid; or

(v) Spaces where flammable gases are not expected to accumulate; and:

(3) Each compartment where flammable gas is expected to accumulate is:

(i) Closed; and

(ii) Secured.