ULC-S111-95 (R2001)

1. Scope 1.1 These requirements cover air filter units of both washable and throw-away types for removal of dust and other airborne particles from air circulated mechanically in equipment and systems. 1.2 Air filter units conforming to the preceding are classified as follows: CLASS 1 UNITS - Those which, when clean, do not burn with a flame or produce sparks and emit only negligible amounts of smoke when tested. (See Clause 5.1 B.) CLASS 2 UNITS - Those which, when clean, burn moderately or emit moderate amounts of smoke when tested. (See Clause 5.2 B.)