Cotton Dust

A disposable respirator means the filter element is an inseparable part of the respirator.

** A high-efficiency filter means a filter that is at least 99.97% efficient against mono-dispersed particles of 0.3 µm (micrometers) in diameter or higher.

Notes: Self-contained breathing apparatus are not required but are permitted respirators.
Supplied-air respirators are not required but are permitted under the following conditions:

Cotton dust concentration not greater than 10X the PEL: Any supplied air respirator; not greater than 100X the PEL: Any supplied-air respirator with full facepiece, helmet, or hood; greater than 100X the PEL: Supplied-air respirator operated in positive-pressure mode.