Publication Date of Users' Notice: May 23, 1996

The National Institute for Occupational Safety and Health (NIOSH) is updating information on (1) the kinds of respirators approved for abrasive-blast (sandblasting) operations and (2) the NIOSH recommendations for selection and use of these respirators. This information replaces the NIOSH Respirator User Notice dated October 4, 1993.

CURRENT CERTIFIED ABRASIVE-BLASTING RESPIRATORS

Type CE abrasive-blast supplied-air respirators are the only respirators suitable for use in abrasive-blasting operations.* Currently, there are four kinds of Type CE abrasive-blast respirators certified by NIOSH. These four kinds of respirators and the NIOSH recommended assigned protection factors^† (APF) are:

(1) a continuous-flow respirator with a loose-fitting hood and an APF of 25;

(2) a continuous-flow respirator with a tight-fitting facepiece and an APF of 50;

(3) a positive-pressure respirator with a tight-fitting half-mask facepiece and an APF of 1000.

(4) a pressure-demand or positive-pressure respirator containing a tight-fitting full facepiece and an APF of 2000.

^†Note: OSHA APFs for abrasive blasting operations may differ somewhat from NIOSH recommended APFs. The reader should consult with his/her local OSHA office for details.

NIOSH recommends the following for all abrasive-blasting operations:

1. Silica sand should NOT be used as an abrasive medium.

2. Respirators should not be used as the only means of preventing or minimizing exposures to airborne contaminants. Dust source controls such as containment systems, local exhaust systems, and good work practices should be implemented as the primary means of protecting workers. When dust source controls cannot keep exposures below the recommended exposure limits, controls should be supplemented with the use of respiratory protection.

3. Environmental monitoring by trained personnel should be conducted in all abrasive-blasting applications. This is necessary to select the proper respirator (APF) and insure that workers are not overexposed (i.e., measured contaminant concentration is less than the exposure limit multiplied by the respirator APF).

4. Anytime environmental conditions, airborne contaminants, or their concentrations are highly variable or poorly defined, high level respiratory protection should be used, even if silica is not the abrasive agent.

5. If silica sand is used, despite its much greater hazard relative to other abrasive agents, only the highest level protection respirators (i.e., respirators certified by NIOSH as pressure-demand or positive pressure and with NIOSH recommended APFs of 1000 or 2000) should be used.

6. Respirators will only provide a satisfactory level of protection when they are selected, fitted, used, and maintained according to the manufacturer's written instructions, NIOSH approval limitations and guidelines, and OSHA regulatory requirements.