This document specifies the general requirements and the constructional and operating characteristics relating to safety, marking, and the associated test methods for gas heated commercial catering and bakery appliances. The specific requirements are given in Part 2. Only appliances of types A1, A2, A3, B1 and B2, as defined in Clause 4, are considered in this document. This document applies to all professional cooking and bakery appliances using gas for preparing food and drink. This document covers type tests only, and only the net calorific value (Hi) and net Wobbe number (Wi) are used. Annex C, informative, lists the main types of equipment entering into the field of application of this document. NOTE This document does not really deal with rational use of energy. This aspect is mentioned in 6.10 only for the coherency with associated Part 2 (clauses numbering) and to remind that in case of not any Part 2 exist for a specific product, rational use of energy has however to be considered.