UL 1666:2021 PDF Download

The UL 1666:2021 standard is a fire test that evaluates the flame propagation height of electrical and optical-fiber cables that are intended for vertical installation in shafts or vertical runs across multiple floors.

The primary objective of this test is to determine whether the flame propagation characteristics of these cables, commonly known as "riser" cables, comply with the requirements set forth in the National Electrical Code. It does not, however, assess the toxicity or corrosivity of the combustion or decomposition by-products of these cables.

It is important to note that this standard does not address the construction requirements of any specific cable, nor does it cover the electrical, optical, or other performance aspects of these cables. Its focus solely lies on evaluating the flame propagation height of the cables when installed vertically in shafts.