(1) Vibration isolation connectors in air duct systems shall be noncombustible, except that combustible fabric connectors are permitted provided they,
(a) do not exceed 250 mm in length,
(b) comply with the flame-resistance requirements of CAN/ULC-S109, “Flame Tests of Flame-Resistant Fabrics and Films”, and
(c) are not used in a location where they are exposed to heated air or radiation from heat sources that may cause the exposed surface to exceed a temperature of 120°C.