Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

February 15, 2000

Robert W. Leighton, Jr.
Maine Department of Labor
Bureau of Labor Standards
45 State House Station
Augusta, ME 04333-0045

Dear Mr. Leighton:

Thank you for your letter dated December 6, 1999 asking about the recording of a baseline measurement for both a company's hearing conservation program and for OSHA injury and illness recordkeeping purposes.

Scenario: An employee began work at company "A" and a baseline measurement was achieved and recorded for future comparison. This employee left the company to work for company "B" and later returned to company "A" six months later. Does the departure for six months have any bearing on the baseline measurement that company A measured when the employee was first with company "A"? Should the baseline be the original measurement or should company "A" perform another measurement to use as a baseline instead. Company "A" is concerned that the employee may have experienced a shift while not employed by them.

Answer: Company "A" should establish a new baseline measurement upon the worker's return to employment with company "A". This will satisfy the requirements under both 1910.95 and 1904.2.

We appreciate the opportunity to clarify these matters for you. I hope you find this information useful. If you have any further questions or comments, please contact the Division of Recordkeeping Requirements at: 202-693-1702.


Cheryle A. Greenaugh
Director, Directorate of Information Technology