June 9, 2017

Mr. A. Gregg Moore
The EI Group, Inc.
2101 Gateway Centre Blvd., Suite 200
Morrisville, North Carolina 27560

Dear Mr. Moore:

Thank you for your letter to the Occupational Safety and Health Administration’s (OSHA) Directorate of Enforcement Programs. You requested guidance on the use of insert earphones when conducting audiometric testing under OSHA’s Occupational noise exposure standard, 29 CFR 1910.95. This letter constitutes OSHA’s interpretation only of the requirements herein, and may not be applicable to any questions not delineated within your original correspondence. Your paraphrased statement and question are presented below, followed by our response.

Background: Your letter stated that OSHA’s August 31, 1993 letter to Dr. Fredrik Lindgren provided that, with some conditions, insert earphones can be used to conduct audiometric testing under OSHA’s noise standard. Among other things, the conditions from that 1993 letter provided that the person responsible for conducting the audiological testing must identify ear canals that prevent an acceptable fit with insert earphones. Your letter also noted that OSHA’s March 11, 2013 letter to David Croft states that insert earphones may be used to conduct audiometric testing without the conditions listed in the 1993 Lindgren letter.

You also state in your letter that OSHA’s Noise standard, Appendix D (mandatory), Audiometric Test Rooms, includes Table D-1, Maximum Allowable Octave-Band Sound Pressure Levels (MAOSPL) for Audiometric Test Rooms, which specifies Maximum Permissible Ambient Noise Levels (MPANL) for supra-aural headphones. However, you claim that insert earphones will attenuate significantly more ambient noise than supra-aural headphones. Also, you state that the American National Standards Institute (ANSI) S3.1-1999 (R 2008) specifies the MPANLs for insert earphones, and limits threshold masking to two decibels (dB). According to your letter, this two dB criterion level is more stringent than what would be obtained with the supra-aural headphones using OSHA’s Noise standard Appendix D.

Question 1: Does OSHA allow the use of ANSI S 3.1-1999 (R 2008) MPANLs in lieu of the MAOSPLs in Appendix D, Table D-1, when insert earphones are used to conduct audiometric testing?

Response: First, please be aware that the 1993 letter to Dr. Lindgren no longer reflects OSHA policy and has since been rescinded and archived. Based on a recommendation from the National Institute for Occupational Safety and Health (NIOSH) to OSHA, the use of insert earphones is acceptable when obtaining audiograms. OSHA will allow the use of ANSI MPANL’s when insert earphones are used for audiometric testing.

Additionally, with respect to OSHA safety and health standards, employers are permitted to adopt more stringent policies, such as the aforementioned two dB criterion level. Please refer to the enclosed March 11, 2013, letter of interpretation addressed to Mr. David Croft for additional information regarding the use of insert earphones.

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 letters of interpretation do not create new or additional requirements but rather explain these requirements and how they apply to particular circumstances. This letter constitutes OSHA's interpretation of the requirements discussed. From time to time, letters are affected when the Agency updates a standard, a legal decision impacts a standard, or changes in technology affect the interpretation.

To assure that you are using the correct information and guidance, please consult OSHA's website at https://www.osha.gov. If you have any further questions, please feel free to contact the Office of Health Enforcement at (202) 693-2190.

Sincerely,

Thomas Galassi, Director
Directorate of Enforcement Programs

Enclosure