These requirements apply to direct-fed incinerators@ including those of the gas and electric ignition types@ designed primarily for use as a crematory (as defined in 5.30). They are not intended to incinerate any hazardous@ including biological/infectious@ chemical and/or explosive@ types of material and not intended for use in spaces in which flammable vapor or gases may be present. These requirements are only intended to cover the safety aspect of the direct-fed incinerators@ with respect to fire@ shock@ mechanical hazards@ and carbon monoxide emissions. Crematories covered by these requirements are the factory-made type and may be field assembled. These requirements do not cover an incinerator that requires the use of a brick or masonry wall@ etc.@ which forms a part of the building structure. Gas-heating incinerators covered by these requirements may be operated without a competent attendant being constantly on duty at the burners while the burners are in operation. Incinerators may be subject to local regulations and/or EPA regulations@ such as the Clean Air Act and/or the Resource Conservation and Recovery Act@ with respect to: a) Particulate emissions@ oxides of nitrogen@ and other products of combustion in the flue gas. These requirements do not include limitations on Nox emissions and only carbon monoxide was required to be within the specified limits. b) The types of wastes to be incinerated. Additional installation and operation requirements are available as defined by the National Fuel Gas Code@ NFPA 54@ the Liquefied Petroleum Gas Code@ NFPA 58@ the National Electrical Code@ NFPA 70 and other codes as applicable.