OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.

January 29, 2010

Ms. Robin R. Anderson
Loss Control Consultant
Highmark Casualty Insurance Company
Suite P6405
P.O. Box 535061
Pittsburgh, PA  15253-5061

Dear Ms. Anderson:

Thank you for your letter to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs.  You requested the definition of single use and negative [pressure] respirators under the Respiratory Protection Standard, 29 CFR 1910.134. You also requested OSHA's interpretation of requirements for respirator use and fit-testing when used to protect against the H1N1 influenza virus.  This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not detailed in your original correspondence.  Your questions are paraphrased below, followed by our responses.

Question [1]:  What is the definition of a single use and negative [pressure] respirator?

Response:  OSHA's Respiratory Protection Standard does not define "single use" respirators.  The "single use respirator" used for protection from the H1N1 Influenza virus usually refers to a disposable N95 filtering facepiece respirator.  Disposable respirators are not required to be discarded at the end of each task, but discarded when they are no longer in their original working condition, whether its condition results from contamination, structural defects, or wear.  A negative pressure respirator means any tight-fitting respirator in which the air pressure inside the facepiece is negative during inhalation with respect to the ambient air pressure outside the respirator. The disposable N95 filtering facepiece respirator is a negative pressure respirator.

Question [2]:  Is fit-testing required for the disposable N95 filtering facepiece respirator used for protection from the H1N1 virus?

Response:  The respiratory protection standard, 29 CFR 1910.134, under paragraph (f)(2), requires fit testing for all employees using tight fitting respirators including filtering facepiece respirators (e.g., disposable N95 respirators). The fit test must be performed before the respirator is used in the workplace and must be repeated at least annually and whenever a different respirator facepiece is used or a change in the employee's physical condition could affect the respirator fit.

Question [3]:  Is a written respiratory protection program needed for the disposable N95 respirator?

Response:  Yes.  A written respiratory protection program, in accordance with 29 CFR 1910.134(c) (including medical evaluation, training, and fit testing), is required in any workplace where respirators (including disposable N95 filtering facepiece respirators) are necessary to protect the health of the employee or whenever respirators are required by the employer.

Question [4]:  Is there any circumstance when the disposable N95 respirator can be used without fit testing?

Response:  The voluntary use of respirators in atmospheres which are not hazardous does not require the respirator to be fit tested or the wearer to maintain a tight fit.

Question [5]:  What are the requirements for the disposable N95 filtering facepiece respirator when it is used for protection from the H1N1 virus?

Response:  As stated above, the use of disposable N95 filtering facepiece respirators in the workplace must be included in an employer's written respiratory protection program.  The respirator program in 29 CFR 1910.134(c) includes medical evaluation, training, and fit testing, and is required in any workplace where respirators (including disposable N95 filtering facepiece respirators) are necessary to protect the health of the employee or whenever respirators are required by the employer.

Thank you for your interest in occupational safety and health.  We hope you find this information helpful.  OSHA requirements are set by statute, standards, and regulations.  Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations.  This letter constitutes OSHA's interpretation of the requirements discussed.  Note that our enforcement guidance may be affected by changes to OSHA rules.  Also, from time to time we update our guidance in response to new information.  To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.  If you have any further questions, please feel free to contact the Office of Health Enforcement at (202) 693-2190.

Sincerely,

Richard E. Fairfax, Director
Directorate of Enforcement Programs