1.1.1 This standard applies to Class A, Class B, Class C, and Class D ovens, dryers, and furnaces, thermal oxidizers, and any other heated enclosure used for processing of materials and related equipment. 1.1.1.1 The terms ovens, dryers, and furnaces are used interchangeably and also apply to other heated enclosures used for processing of materials. 1.1.2* Within the scope of this standard, a Class A, Class B, or Class C oven is any heated enclosure operating at approximately atmospheric pressure and used for commercial and industrial processing of materials. 1.1.3 A Class A oven can utilize a low-oxygen atmosphere. 1.1.4 This standard applies to bakery ovens and Class A ovens, in all respects, and where reference is made to ANSI Z50.1, Bakery Equipment - Safety Requirements, those requirements shall apply to bakery oven construction and safety. 1.1.5 This standard applies to atmosphere generators and atmosphere supply systems serving Class C furnaces and to furnaces with integral quench tanks or molten salt baths. 1.1.6* This standard applies to Class D ovens and furnaces operating above ambient temperatures to over 5000°F (2760°C) and at pressures normally below atmospheric to 10?8 torr (1.33 x 10?6 Pa).