It is intended that this specification be invoked in individual equipment specifications for enclosures for electrical and electronic enclosures. This specification covers the basic requirements applicable to enclosures intended for Naval shipboard use. Minimum degrees of enclosure that are intended to protect contents of the enclosures in typical environments are listed in table III. A lesser degree of enclosure may be satisfactory for a particular application if the equipment itself is inherently protected (such as by encapsulation) or does not require complete exclusion of a potentially harmful element in order to perform satisfactorily; however, such determination will be made, or approved, by the contracting activity responsible for establishing technical requirements. Explosionproof enclosures are required for electric and electronic equipment in hazardous locations (explosive gases or vapors present) regardless of other environmental conditions. Additional protection of explosionproof enclosures, if required, should be obtained by the use of shields or baffles. An exception to the requirement for explosionproof enclosures in hazardous location is the case of "intrinsically safe" installations. An intrinsically safe installation (one in which the energy level is limited to values that preclude ignition of explosive atmospheres) requires the approval of the contracting activity.