(a) Electrical installations in hazardous locations, where necessary for operational purposes, must be located in the least hazardous location practicable.

(b) Electrical installations in hazardous locations must comply with the standards listed in paragraphs (b)(1), (2), or (3) of this section.

(1) NFPA 70 Articles 500 through 504 (incorporated by reference, see §110.10-1). Equipment identified for Class I locations must meet the provisions of Sections 500.7 and 500.8 of NFPA 70 and must be tested and listed by an independent laboratory to any of the following standards:

(i) ANSI/UL 674, ANSI/UL 823, ANSI/UL 844, ANSI/UL 913, ANSI/UL 1203, UL 1604 (Division 2) and/or ANSI/UL 2225 (incorporated by reference, see §110.10-1).

(ii) FM Approvals Class Number 3600, Class Number 3610, Class Number 3611, Class Number 3615, Class Number 3620, or any combination of these (incorporated by reference, see §110.10-1).

(iii) CAN/CSA C22.2 Nos. 0-M91, 30-M1986, 157-92, and/or 213-M1987 (incorporated by reference, see §110.10-1).

Note to §111.106-3(b)(1): See Article 501.5 of NFPA 70 for use of Zone equipment in Division designated spaces.

(2) NFPA 70 Article 505 (incorporated by reference, see §110.10-1). Equipment identified for Class I locations must meet the provisions of Sections 505.7 and 505.9 of NPFA 70 and be tested and listed by an independent laboratory to the ANSI/ISA Series of standards incorporated in NFPA 70.

Note to §111.106-3(b)(2): See Article 505.9(c)(1) of the NFPA 70 for use of Division equipment in Zone designated spaces.

(3) IEC 60092-502 (incorporated by reference, see §110.10-1), with the following exceptions:

(i) Section 111.106-5 of this subpart applies in lieu of Clause 7.3.1.

(ii) Section 111.106-9 of this subpart applies in lieu of Clause 4.2.

(iii) Section 111.106-7 of this subpart applies in lieu of Clauses 4.1.5 and 8.4.

(iv) Section 111.106-13(b) of this subpart applies in lieu of Clause 4.1.4 for enclosed areas containing devices handling hydrocarbons.

(v) Section 111.106-11 of this subpart applies in lieu of Clause 4.3.2.

(vi) Electrical apparatus in hazardous locations must meet one or the combination of IEC 60079-1:2007, IEC 60079-2:2007, IEC 60079-5:2007, IEC 60079-6:2007, IEC 60079-7:2006, IEC 60079-11:2006, IEC 60079-13:2010, IEC 60079-15:2010, IEC 60079-18:2009 or IEC 60079-25:2010 (incorporated by reference, see §110.10-1) in lieu of Clause 6.5.

(vii) Equipment must be tested by an Ex Testing Laboratory and certified by an Ex Certification Body under the IECEx System, in lieu of Clause 6.3.

Note to §111.106-3(b): System components that are listed or certified under paragraph (b)(1), (b)(2) or (b)(3) of this section must not be combined in a manner that would compromise system integrity or safety.

(c) As an alternative to paragraph (b)(1) of this section, electrical equipment that complies with the provisions of NFPA 496 (2008) (incorporated by reference, see §110.10-1) is acceptable for installation in Class I, Divisions 1 and 2. When equipment meeting this standard is used, it does not need to be identified and marked by an independent laboratory. The Commanding Officer, Marine Safety Center (MSC) will evaluate equipment complying with this standard during plan review. It is normally considered acceptable if a manufacturer's certification of compliance is indicated on a material list or plan.

(d) Equipment listed or certified to ANSI/ISA 60079-18 or IEC 60079-18:2009, respectively, (incorporated by reference, see §110.10-1) is not permitted in Class I Special Division 1 or Zone 0 hazardous location, unless the encapsulating compound of Ex “ma” protected equipment is not exposed to, or has been determined to be compatible with, the liquid or cargo in the storage tank.

(e) Lighting circuits serving flameproof or explosion-proof lighting fixtures in an enclosed hazardous space or room must—

(1) Have at least two lighting branch circuits;

(2) Be arranged so that there is light for relamping any de-energized lighting circuit;

(3) Not have the switch and overcurrent device within the space for those spaces containing explosion-proof or flameproof lighting fixtures; and

(4) Have a switch and overcurrent protective device that must open all ungrounded conductors of the circuit simultaneously.

(f) Submerged pump motors that do not meet the requirements of §111.105-31(d), installed in tanks carrying flammable or combustible liquids with closed-cup flashpoints not exceeding 60 °C (140 °F), must receive concept approval by the Commandant (CG-ENG) and plan approval by the Commanding Officer, MSC.

(g) Wiring materials and cables in hazardous locations must meet the construction and testing requirements in §111.106-5 of this subpart.

(h) Internal combustion engines installed in Divisions 1 and 2 (Zones 1 and 2) must meet the provisions of ASTM F2876-10 (incorporated by reference, see §110.10-1).

(i) Cofferdams are required to separate enclosed spaces adjacent to integral cargo storage tanks.

(j) The cargo pumping/piping systems must be arranged independently from all other systems. Cargo transfer pumps and piping (including fill, discharge, vent, and sounding piping) must not be located in or pass through any accommodation, service, or machinery spaces.