OSHA Standard Interpretations​

From the United States Department of Labor,
Occupational Safety & Health Administration


Cyanide Antidotes

STANDARD NUMBER: 1910.126(e) ; 1910.151 ; 1910.151(a) ; 1910.1000

Cyanide Antidotes

March 31, 2020



Principal Deputy Assistant Secretary

Directorate of Technical Support and Emergency Management

PATRICK J. KAPUST, Acting Director
Directorate of Enforcement Programs

SUBJECT: Cyanide Antidotes

This memorandum serves as new guidance to address outdated information provided in OSHA’s archived memo dated May 17, 1988, from the Office of Occupational Medicine, and entitled “Cyanide Antidote Kits.”  The prior memo stated in part, “Amyl Nitrite continues to require a physician’s prescription and the administration of this drug in an emergency situation by the designated first aide responder is the medically accepted initial response.  According to current literature, hydroxy cobalamine has had limited use as an alternative intravenous medication to the widely accepted sodium nitrite protocol.”1

This memo provides the following updated information regarding cyanide antidotes:

  • Amyl nitrite (which was given via inhalation) is no longer available in cyanide antidote kits in the U.S., and is no longer an acceptable initial therapeutic response.
  • Currently, the available cyanide antidotes are hydroxocobalamin, sodium nitrite, and sodium thiosulfate.
  • The three available antidotes are given via intravenous (IV) infusion and, therefore, can only be administered by qualified healthcare professionals.


Antidote kits containing inhaled amyl nitrite are no longer commercially available.2  The U.S. Food and Drug Administration (FDA) stated, as of September 2018, that the only products approved for cyanide poisoning are the following:  Cyanokit (hydroxocobalamin injection), Nithiodote (sodium nitrite and sodium thiosulfate for intravenous infusion), sodium nitrite injection, and sodium thiosulfate injection.3  In 2018, an expert consensus panel determined that hydroxocobalamin is the preferred antidote, but sodium nitrite and sodium thiosulfate are also acceptable.2  In light of the experts’ recommendation to use hydroxocobalamin, and the absence of amyl nitrite on the FDA list of approved cyanide antidotes,3 amyl nitrite is no longer an acceptable antidote option.

Employers that offer antidote therapy for cyanide poisoning should provide one of the FDA-approved products.  Ideally, cyanide antidotes should be given soon after exposure to unconscious victims with known or strongly suspected cyanide poisoning.2,4,5  Because all currently FDA-approved cyanide antidotes are IV infusions, they should only be given by healthcare professionals whose scope of practice includes administration of IV drugs.  Employers should heed all aspects of the antidote’s “Indications and Usage” labeling.  In addition to specific antidotes, cyanide poisoning requires other therapeutic interventions. Depending on the scenario, victims might require cardiopulmonary resuscitation, supplemental 100% oxygen, decontamination, and other supportive care.4,5  Most cyanide exposures will result in activation of emergency medical services (EMS).  EMS providers could assist with administration of antidotes or non-specific therapies.  Therefore, when there is a foreseeable risk of cyanide exposure, employers should communicate with their local EMS agency to plan for exposure controls, hazard recognition, training, and treatment availability.

Inspection guidance

Due to the acute and lethal hazards presented by cyanide poisoning, an employer covered under OSHA’s standard, Medical Services and First Aid, 29 CFR 1910.151(a), with a workplace that has a foreseeable risk of cyanide exposure, must consult with a physician or other licensed health care professional (PLHCP).  This consultation shall ensure that emergency medical services, including those equipped with effective cyanide antidotes, are readily available in the event of an acute cyanide overexposure in the workplace.  The absence of such consultation is enforceable as a serious violation.

Specifically, this medical consultation should address workplace-specific considerations, such as appropriate storage and replenishment of medical supplies (e.g., FDA-approved antidote drugs, intravenous supplies), and pre-placement of emergency medical equipment and first-aid supplies (e.g., portable oxygen tanks, automated external defibrillators or AEDs).  Where appropriate, consultation shall also address on-site staffing, training, and licensing requirements of first aid and medical responders; wait times for EMS/ambulance arrival; when and how intravenous drugs can be administered; worker susceptibility, etc.  Compliance officers shall bring any deficiencies in the availability of medical supplies or personnel to the attention of their supervisor and, as needed, to their Regional Office for further evaluation.

Additionally, for workplaces with potential cyanide exposures, other applicable OSHA standards may include, but are not limited to:  29 CFR 1910 Subpart E, Exit Routes and Emergency Planning; Subpart H, Hazardous Materials – Dipping and Coating Operations; Subpart I, Personal Protective Equipment; 29 CFR 1910.94 Ventilation; and 29 CFR 1910.1200, Hazard Communication.

If you have any questions, please contact Dr. Michael Hodgson, hodgson.michael@dol.gov,

(202) 693-1768, with the Office of Occupational Medicine and Nursing, Directorate of Technical Support and Emergency Management, or Dr. Dionne Williams, williams.dionne@dol.gov, (202) 693-2140, with the Directorate of Enforcement Programs.


1. Archived OSHA memorandum “Cyanide Antidote Kits,” dated May 17, 1988. Available at: https://www.osha.gov/laws-regs/standardinterpretations/1988-05-17-0

2. Dart RC, Goldfrank LR, Erstad BL, et al. Expert consensus guidelines for stocking of antidotes in hospitals that provide emergency care. Annals of Emergency Medicine 2018;71(3):314-325. Available at: https://www.annemergmed.com/article/S0196-0644(17)30657-1/fulltext

3. U.S. Food and Drug Administration (FDA). Products approved for chemical emergencies: products for cyanide poisoning. Updated September 27, 2018. Available at: https://www.fda.gov/drugs/bioterrorism-and-drug-preparedness/products-approved-chemical-emergencies

4. Agency for Toxic Substances & Disease Registry (ATSDR). Medical management guidelines for hydrogen cyanide (HCN). Available at: https://www.atsdr.cdc.gov/mmg/mmg.asp?id=1073&tid=19

5. U.S. Department of Health & Human Services, Chemical Hazards Emergency Medical Management (CHEMM). Hydrogen cyanide – emergency department/hospital management. Available at: https://chemm.nlm.nih.gov/cyanide_hospital_mmg.htm#top

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.

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