Listed & Labeled

The 2018 edition of the International Mechanical Code® added new language and requirements for duct insulation coverings (wrap) and linings (liner), including adhesives, contained within plenums.

Within Section 604.3 Insulation Coverings and Linings, the new requirement states that duct insulation and adhesives must be “listed and labeled.” What exactly does this mean?

Duct Insulation must pass either ASTM E84 or UL723 25/50 flame spread (< 25) and smoke- developed (< 50) indexes. This requirement is not new.

What’s new is that duct insulation manufacturers must engage with an OSHA-approved nationally recognized testing laboratory (NRTL) for initial and periodic (quarterly) testing/surveillance to ensure that their duct insulation passes ASTM E84 or UL723 perpetually.

Once a duct insulation and adhesive passes 25/50, the manufacturer’s products are publicly listed on the NRTL’s online product directory. This is the definition of “listed”. Below is a screenshot of AEROFLEX Breathe-EZTM Duct Insulation listed with Southwest Research Institute.

Aeroflex USA

The NRTL’s logo and approved language must be labeled on the approved duct insulation and adhesive packaging (cartons). This is what is meant by “labeled”. Below is an example of a NRTL approval embedded into a product label. However, the label can be placed separately per the NRTL.

Aeroflex USA

Additionally, ASTM C1534 “Standard Specification for Flexible Polymeric Foam Sheet Insulation Used as a Thermal and Sound Absorbing Liner for Duct Systems” maintains specific requirements for elastomeric duct liner.

To meet the above industry requirements, Aeroflex USA offers AEROFLEX Breathe-EZTM EPDM Duct Insulation so building owners, consulting mechanical engineers, design-build mechanical contractors, and acoustic consultants can confidently specify a fiber-free duct liner or wrap to meet the owner’s project requirements.