This document specifies the requirements and test methods for the construction, safety, and marking of decorative fuel effect gas appliances not exceeding a nominal heat input of 20 kW (based on the net calorific value), thereafter referred to as appliances. This document is applicable to appliances that are designed to simulate a solid fuel fire and incorporate a natural draught burner with or without an ignition burner. The appliances are for decorative purposes only and are not heating appliances. This document is applicable to type BAS, as described in 4.2, decorative fuel effect gas appliances that are designed to be installed within a non-combustible builder's opening or a non-combustible fireplace recess. This document includes additional requirements for Type BBS appliances which are specified in Annex F. In addition, this document is applicable to decorative fuel-effect gas appliances that are designed to be installed under a non-combustible canopy which which is independent or integral with a flue box, for which additional requirements are specified in Annex A. This document is not applicable to: catalytic combustion appliances; appliances in which the supply of combustion air and/or the evacuation of products of combustion is achieved by mechanical means. This document is only applicable to appliances which are intended to be type tested. Matters related to quality assurance systems, tests during production and to certificates of conformity of auxiliary devices are not dealt with by this document. Requirements concerning the rational use of energy have not been included in this document because the appliances are for decorative purposes.