The Ontario Building Code | Light Diffusers and Lenses
188.8.131.52. light Diffusers and Lenses
(1) The flame-spread rating of combustible light diffusers and lenses in all occupancies other than Group A, Division 1 is permitted to be more than the flame-spread rating limits required elsewhere in this Subsection, provided the light diffusers and lenses,
(a) have a flame-spread rating not more than 250 and a smoke developed classification not more than 600 when tested in conformance with CAN/ulc-S102.2, "Test for surface Burning Characteristics of flooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring, Floor Coverings, and Miscellaneous Materials and Assemblies",
(d) are not used in a corridor that is required to be separated from the remainder of the buildingby a fire separation or in an exitshaft unless individual diffusers or lenses are not more than 1 m2in area and are not less than 1.2 m apart.