HVAC duct insulation adhesive

Use an adhesive product that the insulation manufacturer recommends, but base the VOC limit on the characteristics of the adhesive and of the substrates to which the adhesive is applied. For example, does the adhesive glue the insulation directly to metal ductwork? Does it adhere the insulation to itself, or do you apply the adhesive to a foil, paper, or fabric wrapping on the outside of the insulation? Refer to SCAQMD 1168 for definitions of the adhesive categories. First, compare product data for the adhesive to the “Substrate-Specific Application” types (foam, fiberglass, foil, or porous materials) to see whether the product matches these applications. It might also be a “Contact Adhesive” if the application method matches that described in its SCAQMD definition. (However, a “Special Purpose Contact Adhesive” is for use only on the substrates named by its definition.) If the adhesive is recommended exclusively for duct insulation, it is not a “Multipurpose Construction Adhesive.” By definition, this type is for use with various materials.