Q: Do fiber glass duct liners or duct boards release fibers into the air stream?
A: Duct liners and duct boards manufactured by Johns Manville have been evaluated by the erosion resistance test of UL 181. The UL standard requires that the product not break away, crack, peel, flake off, or show evidence of delaminating or continued erosion when subjected to air velocities 2.5 times their rated air stream velocities in a test duct run that includes a 90 degree elbow.
Johns Manville has conducted even more demanding testing on SuperDuct™. During a 7 hour run with the UL 181 test apparatus isokinetic air sampling was done near the duct outlet. (Isokinetic means that the sampled air was drawn off at a velocity equal to the velocity of the air stream to ensure suspended solids would be properly captured.) Analysis by Phase Contrast Microscopy following NIOSH Method #7400 demonstrated no detectable glass fibers. (The limit of detection was 0.01 fiber/cc.)
Further Information
Fiber Erosion Testing, Johns Manville Health, Safety & Environment Fact Sheet on Indoor Air Quality, HSE-133FS
"The Facts About Airborne Fibers" NAIMA Insulation Facts #50, AH114, available from the North American Insulation Manufacturers Association,
http://www.naima.org/.
