These requirements cover portable and fixed electric baseboard heating equipment rated at 600 volts or less@ to be employed in ordinary locations in accordance with the National Electrical Code@ ANSI/NFPA 70. Baseboard heating equipment includes baseboard heaters and baseboard heater accessories. Electric baseboard heating equipment intended for use in a hazardous location is judged on the basis of compliance with the requirements in this standard@ together with those recognized requirements applicable to usage in hazardous locations. Any air heating appliance sold or recommended for use as a baseboard heater@ irrespective of its dimensions or other characteristics@ is to be identified as a baseboard heater. It will be categorized as a fixed or portable baseboard heater in accordance with the following: a) Fixed ?C A heater is identified as a fixed baseboard heater if: 1) The heater is less than 6 in (150 mm) in overall depth@ the ratio of the overall length to the overall height is more than two to one@ and the heater can be installed completely within a space of 18 in (460 mm) above the floor; or 2) The heater enclosure is intended to be connected to other heater enclosures to form a system. Exception: A heater intended for ceiling mounting or suspended mounting or marked ?Do Not Install Less Than 6 Feet From Floor ? is not considered to be a baseboard heater even if it meets the specifications in (1) or (2) above. b) Portable ?C A portable heater is identified as a baseboard heater if@ excluding projections of guard or feet@ it is less than 5 in (130 mm) in depth and if the ratio of its overall length to its height without the handle is as follows: