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Marking laboratory faucets as nonpotable

Summary A laboratory asked whether deionized, reverse-osmosis or ordinary faucets had to be marked nonpotable. OSHA said the marking turns on whether the water meets applicable drinking-water standards, regardless of how the laboratory uses it. A faucet supplying water that does not meet that definition must be clearly marked unsafe for drinking and other personal uses.
Document
Federal opinion letter
Agency
Occupational Safety and Health Administration (OSHA)
Document number
2013-02-04-1
Date issued
February 4, 2013
Status
Active
Status last verified October 8, 2026

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About this page: The full text below is the official document from Occupational Safety and Health Administration (OSHA). Ezel adds the plain-English summary and tracks the document's status. The official source linked on this page is authoritative for any reliance.

February 4, 2013

Jason M. Keaton

[Recipient address omitted]

Dear Mr. Keaton:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA). This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any scenario or questions not delineated within your original correspondence. In your letter, you asked two specific questions regarding whether certain sink faucets at your research facility should be labeled as nonpotable. Your paraphrased questions and our responses are provided below.

Question: At the laboratory space in your research facility, there are sink faucets that dispense water provided by the local department of public works and faucets that dispense deionized (DI) or reverse osmosis (RO) water generated at and provided by the same local department of public works. Is your facility required to label either of those faucets as nonpotable?

Response: OSHA's Sanitation standard, 29 CFR 1910.141(b)(2)(i), requires:

Outlets for nonpotable water, such as water for industrial or firefighting purposes, shall be posted or otherwise marked in a manner that will indicate clearly that the water is unsafe and is not to be used for drinking, washing of the person, cooking, washing of food, washing of cooking or eating utensils, washing of food preparation or processing premises, or personal service rooms, or for washing clothes.

Nonpotable water is water that does not meet OSHA's Sanitation standard for potable water. OSHA's Sanitation standard, at 29 CFR 1910.141(a)(2), defines potable water as:

Water that meets the standards for drinking purposes of the State or local authority having jurisdiction, or water that meets the quality standards prescribed by the U.S. Environmental Protection Agency's National Primary Drinking Water Regulations.

If the water from any of the faucets you described does not meet this definition, then you need to mark those faucets according to 29 CFR 1910.141(b)(2)(i).

You should confirm with your State or local authority having jurisdiction whether the water from any of your faucets meets their standards for drinking purposes or you may consult the U.S. Environmental Protection Agency's National Primary Drinking Water Regulations available at http://water.epa.gov/drink/contaminants/index.cfm.

Question: With regard to 29 CFR 1910.141(b)(2)(i) and to determine whether the water is potable or nonpotable, what is the operational definition of "industrial purposes?"

Response: The purpose for which you are using the water is not a factor in determining whether the water is potable or nonpotable as your letter suggested. You only need to confirm whether the water from any of the faucets meets OSHA's Sanitation standard for potable water.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA's 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 http://www.osha.gov. If you have further questions, please feel free to contact the Directorate of Enforcement Programs at (202) 693-2100.

Sincerely,

Thomas Galassi, Director

Directorate of Enforcement Programs

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