This standard applies to three types of distillate fuel oils suitable for use in liquid-fuel-burning equipment without preheating, and three types of fuel oils which may contain residual fuel components and may require preheating.

The fuel oils covered by this standard are intended for use in oil-burning equipment for the generation of heat for domestic and industrial purposes.

Types 0, 1 and 2 fuel oils are primarily for use in domestic-type oil burners. They may also be used for some industrial purposes.

a. Type 0 fuel oil is intended for use in fuel-oil-burning appliances in the far northern regions where ambient temperature as low as -48C are encountered.

b. Type 1 fuel oil is intended primarily for use in sleeve-type and wick-feed burners, and in most vaporizing pot-type burner applications. It is also intended for atomizing burners in which Type 2 fuel oil cannot be used satisfactorily.

c. Type 2 fuel oil is a heavier distillate than Type 1 and is intended for use in most atomizing-type burner applications. This type of fuel oil is used in most domestic burners (furnaces/boilers) and in some medium capacity commercial-industrial burners where ease of handling and ready availability may justify its use.

Types 4, 5 and 6 fuel oils are essentially industrial fuels suitable for use in boilers, metallurgical operations, etc.

a. Type 4 is an industrial type of fuel oil intended primarily for burner installations not equipped with preheating facilities.

b. Type 5 is a residual type of fuel oil for burner installations equipped with preheating facilities requiring a fuel oil of lower viscosity than Type 6.

c. Type 6 is a high-viscosity residual fuel oil for use in burners equipped with preheating facilities adequate for handling fuel oil of high viscosity.

The testing and evaluation of a product against this standard may require the use of materials and/or equipment that could be hazardous. This document does not purport to address all the safety aspects associated with its use. Anyone using this standard has the responsibility to consult the appropriate authorities and to establish appropriate health and safety practices in conjunction with any applicable regulatory requirements prior to its use.