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Facts About Nitrogen Mustards

What nitrogen mustards are

  • Nitrogen mustards were produced in the 1920s and 1930s as potential chemical warfare weapons. They are vesicants (or blister agents) similar to the sulfur mustards.
  • Nitrogen mustards come in different forms that can smell fishy, musty, soapy, or fruity. They can be in the form of an oily-textured liquid, a vapor (the gaseous form of a liquid), or a solid. Nitrogen mustards are liquids at normal room temperature (70ºF).
  • Nitrogen mustards can be clear, pale amber, or yellow-colored when in liquid or solid form.
  • The nitrogen mustards are also known by their military designations of HN-1, HN-2, and HN-3.

Where nitrogen mustards are found and how they are used

  • The nitrogen mustards were never used in warfare.
  • Nitrogen mustards are not found naturally in the environment.
  • HN-1 originally was designed to remove warts but was later identified as a potential chemical warfare agent.
  • HN-2 was designed as a military agent but was later used in cancer treatment. Other treatment agents now have replaced it.
  • HN-3 was designed solely as a military agent.

How you could be exposed to nitrogen mustards

  • If nitrogen mustards are released into the air as a vapor, you could be exposed through skin contact, eye contact, or breathing.
  • If nitrogen mustards are released into water, you could exposed by drinking the contaminated water or getting it on your skin.
  • You could be exposed by coming in direct contact with liquid nitrogen mustards.
  • Because it is heavier than air, nitrogen mustard vapor will settle in low-lying areas.

How nitrogen mustards work

  • Adverse health effects caused by nitrogen mustards depend on the amount of nitrogen mustard to which people are exposed, the route of exposure, and the length of time that people are exposed.
  • Nitrogen mustards are powerful irritants that damage the skin, eyes, and respiratory (breathing) tract.
  • Nitrogen mustards can enter the cells of the body very quickly and damage the immune system and bone marrow.

Immediate signs and symptoms of nitrogen mustard exposure

  • Typically, signs and symptoms of nitrogen mustard exposure do not occur immediately. Depending on the severity of the exposure, symptoms may not occur for several hours.
  • Nitrogen mustards can have the following effects on specific parts of the body:
    • Skin: redness usually develops within several hours after exposure followed by blistering within 6 to 12 hours.
    • Eyes: irritation, pain, swelling, and tearing may occur. High concentrations can cause burns and blindness.
    • Respiratory tract: nose and sinus pain, cough, sore throat, and shortness of breath may occur within hours. Fluid in the lungs is uncommon.
    • Digestive tract: abdominal pain, diarrhea, nausea, and vomiting.
    • Brain: tremors, incoordination, and seizures are possible following a large exposure.
  • Showing these signs or symptoms does not necessarily mean that a person has been exposed to a nitrogen mustard.

Possible long-term health effects

  • Exposure to nitrogen mustard liquid is more likely to produce second- and third- degree burns and later scarring than is exposure to nitrogen mustard vapor.
  • Extensive breathing in of the vapors can cause chronic respiratory disease.
  • Extensive eye exposure can cause long-lasting eye problems.
  • Nitrogen mustards may cause bone marrow suppression beginning as early as 3 to 5 days after exposure. Bone marrow suppression can cause anemia, bleeding, and increased risk for infection. If severe, these effects could lead to death.
  • Prolonged or repeated exposures to nitrogen mustards have caused cancer in animals. Some evidence exists that prolonged or repeated exposures to nitrogen mustards cause leukemia in humans.

How you can protect yourself, and what you should do if you are exposed to nitrogen mustards

  • Because no antidote exists for nitrogen mustard exposure, the best thing to do is avoid it. If the nitrogen mustard release was indoors, get out of the building. If the release was outdoors, move away from the area of the release, stay upwind if possible, and seek higher ground. Quickly moving to an area where fresh air is available is highly effective in reducing the possibility of death from exposure to nitrogen mustard.
  • If you are near a nitrogen mustard release, emergency coordinators may tell you either to evacuate the area or “shelter in place” inside a building to avoid being exposed to the chemical. For more information about evacuation during a chemical emergency, see “Facts About Evacuation”. For more information about sheltering in place during a chemical emergency, see “Facts About Sheltering in Place”.
  • If you think you may have been exposed, you should remove your clothing, rapidly wash your entire body with soap and water, and get medical care as quickly as possible.
  • Removing your clothing:
    • Quickly take off clothing that has nitrogen mustard on it. Any clothing that has to be pulled over the head should be cut off the body instead of pulled over the head.
  • Washing yourself:
    • As quickly as possible, wash any nitrogen mustard from your skin with large amounts of soap and water. Washing with soap and water will help protect people from any chemicals on their bodies.
  • Disposing of your clothes:
  • If nitrogen mustard has been ingested (swallowed), do not induce vomiting or give fluids to drink.

How nitrogen mustard exposure is treated

No antidote exists for nitrogen mustard exposure. Treatment consists of removing the nitrogen mustard from the body as soon as possible and providing supportive medical care in a hospital setting.

Where you can get more information about nitrogen mustards

You can contact one of the following:

  • Centers for Disease Control and Prevention
    • Public Response Hotline (CDC)
      • 800-CDC-INFO
      • 888-232-6348 (TTY)
    • E-mail inquiries:

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