Type I adhesive is intended for use at installation temperatures of 50°F. or above, and in locations where flammability and explosion hazards prohibit the use of type II. Type II adhesive is intended for use both at lower temperatures and for prefabrication of parts from insulation in areas where adequate fire protection is provided and a limitation on the quantity of adhesive present is enforced. The selection of the class of type II adhesive depends on the bonding operation to be performed and on the atmospheric conditions during use.

Class 1 adhesive is best suited for assembly of prefabricated parts from plastic form insulation and for joining seams in plastic pipe insulation, since very short assembly periods are desirable in these operations. Class 1 adhesive is also suitable for attaching sheets of insulation to the interior surfaces of ships hulls if the temperature of the hull is 45°F. or lower and rapid air movement over the open surfaces coated with adhesive can not be provided.

Class 2 adhesive is recommended for use when rapid air movement is provided at low temperatures. Class 2 adhesive is also appropriate for use at higher temperatures in very humid, still air since in this atmosphere type I adhesive requires very long drying periods.

Type III adhesive is intended for general use in areas where type I and II are not specified and where halogenated solvents can be tolerated. Type III can be used in these areas with relatively little flammability and explosion risks. Types II and III require much shorter drying time before assembly than type I.