This Standard applies to newly produced, gas-fired low-intensity infrared heaters and infrared radiant tube heaters (see Clause 3, Definitions), hereinafter referred to as heaters or appliances, constructed entirely of new, unused parts and materials with inputs up to and including 400 000 Btu/hr (117.23 kW) per burner:
a) for use with natural gas;
b) for use with manufactured gas;
c) for use with mixed gas;
d) for use with propane gas;
e) for use with LP gas-air mixtures; and
f) convertible for use with natural gas and propane gas, when provision is made for the simple conversion from one gas to the other.

The heaters covered by this Standard are intended for installation in and heating of outdoor spaces or nonresidential indoor spaces and are intended for location where flammable gases or vapors are not generally present. Although heaters covered by this Standard may, in certain instances, be suitable for application in industrial processes, this Standard does not cover industrial process burners.