"This part of IEC 60079 contains the specific requirements for the construction and testing of electrical equipment with pressurized enclosures@ of type of protection ""p""@ intended for use in explosive gas atmospheres or explosive dust atmospheres. It also includes the requirements for pressurized enclosures containing a limited release of a flammable substance. This standard supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this standard conflicts with a requirement of IEC 60079-0@ the requirements of this standard take precedence. This standard does not include the requirements for: pressurized enclosures where the containment system may release a) air with an oxygen content greater than normal@ or b) oxygen in combination with inert gas where the oxygen is in a proportion greater than 21 %. pressurized rooms or analyser houses; see IEC 60079-13 pressurized enclosures used where ""explosives"" or pyrotechnics are present; pressurized enclosures used where hybrid mixtures of gas/vapour and combustible dust are present; pressurized enclosures used where pyrophoric substances such as explosives or propellants containing their own oxidizers are present; pressurized enclosures with an internal source of release of combustible dust. NOTE When the user acts in the role of the manufacturer@ it is typically the user's responsibility to ensure that all relevant parts of this standard are applied to the manufacturing and testing of the equipment."