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 https://www.osha.gov.

October 29, 2020

Ms. Denyse C. DuBrucq, EdD
CryoRain, Inc.
2300 Eden Lane
Dayton, OH 45431-1909

Dear Ms. DuBrucq:

Thank you for your email to the Occupational Safety and Health Administration (OSHA). You have requested OSHA, among other federal agencies, evaluate the use of your products that deliver pure nitrogen gas clouds for a variety of applications, such as fire suppression.

Your email expressed that some medical and safety uses of pure nitrogen are under research by your company. You also assert that because OSHA and other federal agencies have classified nitrogen gas as a simple asphyxiant, your marketing and research opportunities have been limited.

Please note OSHA does not register, certify, approve, or otherwise endorse commercial products. However, the agency can clarify the application of health and safety standards to particular facts, as summarized below.

As you know, nitrogen has an inherent hazard of being a simple asphyxiant, and if not used properly in certain workplace applications, workers may be injured or killed. In accordance with the Occupational Safety and Health Act of 1970, OSHA has a mandate to regulate hazards in the workplace. While OSHA has no specific standard for nitrogen, we have a number of standards that govern its use in the workplace, including the duty to inform employees using nitrogen of hazards and safe use. For your information, below is a list of OSHA standards and guidance related to protecting workers from the known hazards of nitrogen.

  • OSHA Standard, 29 CFR § 1910.1200, Hazard Communication, available at www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1200; contains requirements for labeling of containers, availability of safety data sheets, and training for workers on the hazards associated with chemicals, including nitrogen;
  • OSHA Standard, 29 CFR § 1910.1450, Occupational Exposure to Hazardous Chemicals in Laboratories, available at www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1450; contains requirements on laboratory use and scale for workers using hazardous chemicals in a laboratory setting, including nitrogen;
  • OSHA Standard, 29 CFR § 1910.101, Compressed Gases, available at www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.101; contains requirements for safe handling and use of compressed gases, including nitrogen;
  • OSHA Publication,Laboratory Safety: Cryogens and Dry Ice Quick Facts (OSHA 3408 - 2011), available at www.osha.gov/Publications/laboratory/OSHAquickfacts-lab-safety-cryogens-dryice.pdf; contains precautions for safe handling and use of liquid nitrogen; and
  • OSHA Letter of Interpretation, Guidance on whether an inert gas in the non-compressed state represent hazardous chemicals under the Hazard Communication Standard, January 25, 1995, available at www.osha.gov/laws-regs/standardinterpretations/1995-01-25; contains clarification of OSHA’s classification of nitrogen/other inert gases as hazardous in the context of the Hazard Communication Standard, 29 CFR § 1910.1200.

Thank you for your interest in occupational safety and health. I hope you find this information helpful. OSHA’s requirements are set by statute, standards, and regulations. 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 further questions, please contact the Office of Health Enforcement at (202) 693-1890.


Patrick J. Kapust, Acting Director
Directorate of Enforcement Programs