Mustard-Lewisite Mixture (HL): Blister Agent

CAS #:
Mixture of Sulfur Mustard (HD): ClCH2CH2SCH2CH2Cl and Lewisite (L): C2H2AsCl3

RTECS #: Not established/determined

UN #: 2810 (Guide 153)

Common Names:

  • HL
  • Sulfur Mustard/Lewisite

Agent Characteristics

Dark, oily liquid.

Mustard-lewisite (military designation HL) is a mixture of two chemical warfare agents (sulfur mustard and lewisite) and has some properties of both. It is both a blister agent (vesicant) and an alkylating agent (causes damage to the DNA of rapidly dividing cells). Exposure to large amounts of mustard-lewisite may be fatal. The mustard-lewisite mixture requires lower ambient temperatures before it will freeze; this property allows for improved ground dispersal and aerial spraying. Mustard-Lewisite mixture may have a garlic odor. Odor however, should not be depended on to detect mustard-lewisite mixture. /li>

  • Indoor Air: Mustard-Lewisite mixture can be released into indoor air as a liquid spray (aerosol).
  • Water: Not established/determined
  • Food: Not established/determined
  • Outdoor Air: Mustard-Lewisite mixture can be released into outdoor air as a liquid spray (aerosol).
  • Agricultural: If mustard-lewisite mixture is released into the air as a liquid spray (aerosol), it has the potential to contaminate agricultural products.

Mustard-Lewisite mixture can be absorbed into the body by inhalation, ingestion, skin contact, or eye contact. Inhalation is an important route of exposure. Ingestion is an uncommon route of exposure.


Personal Protective Equipment

First Responders should use a NIOSH-certified Chemical, Biological, Radiological, Nuclear (CBRN) Self Contained Breathing Apparatus (SCBA) with a Level A protective suit when entering an area with an unknown contaminant or when entering an area where the concentration of the contaminant is unknown. Level A protection should be used until monitoring results confirm the contaminant and the concentration of the contaminant.
NOTE: Safe use of protective clothing and equipment requires specific skills developed through training and experience.

Select when the greatest level of skin, respiratory, and eye protection is required. This is the maximum protection for workers in danger of exposure to unknown chemical hazards or levels above the IDLH or greater than the AEGL-2.

  • A NIOSH-certified CBRN full-face-piece SCBA operated in a pressure-demand mode or a pressure-demand supplied air hose respirator with an auxiliary escape bottle.
  • A Totally-Encapsulating Chemical Protective (TECP) suit that provides protection against CBRN agents.
  • Chemical-resistant gloves (outer).
  • Chemical-resistant gloves (inner).
  • Chemical-resistant boots with a steel toe and shank.
  • Coveralls, long underwear, and a hard hat worn under the TECP suit are optional items.

Select when the highest level of respiratory protection is necessary but a lesser level of skin protection is required. This is the minimum protection for workers in danger of exposure to unknown chemical hazards or levels above the IDLH or greater than AEGL-2. It differs from Level A in that it incorporates a non-encapsulating, splash-protective, chemical-resistant splash suit that provides Level A protection against liquids but is not airtight.

  • A NIOSH-certified CBRN full-face-piece SCBA operated in a pressure-demand mode or a pressure-demand supplied air hose respirator with an auxiliary escape bottle.
  • A hooded chemical-resistant suit that provides protection against CBRN agents.
  • Chemical-resistant gloves (outer).
  • Chemical-resistant gloves (inner).
  • Chemical-resistant boots with a steel toe and shank.
  • Coveralls, long underwear, a hard hat worn under the chemical-resistant suit, and chemical-resistant disposable boot-covers worn over the chemical-resistant suit are optional items.

Select when the contaminant and concentration of the contaminant are known and the respiratory protection criteria factors for using Air Purifying Respirators (APR) or Powered Air Purifying Respirators (PAPR) are met. This level is appropriate when decontaminating patient/victims.

  • A NIOSH-certified CBRN tight-fitting APR with a canister-type gas mask or CBRN PAPR for air levels greater than AEGL-2.
  • A NIOSH-certified CBRN PAPR with a loose-fitting face-piece, hood, or helmet and a filter or a combination organic vapor, acid gas, and particulate cartridge/filter combination or a continuous flow respirator for air levels greater than AEGL-1.
  • A hooded chemical-resistant suit that provides protection against CBRN agents.
  • Chemical-resistant gloves (outer).
  • Chemical-resistant gloves (inner).
  • Chemical-resistant boots with a steel toe and shank.
  • Escape mask, face shield, coveralls, long underwear, a hard hat worn under the chemical-resistant suit, and chemical-resistant disposable boot-covers worn over the chemical-resistant suit are optional items.

Select when the contaminant and concentration of the contaminant are known and the concentration is below the appropriate occupational exposure limit or less than AEGL-1 for the stated duration times.

  • Limited to coveralls or other work clothes, boots, and gloves.

Emergency Response

  • At 149°F (65°C), mustard-lewisite mixture is rapidly corrosive to brass and will corrode steel at 0.0001 inch per month.
  • Hydrolysis of mustard-lewisite mixture yields hydrochloric acid, thiodiglycol and non-vesicant arsenic compounds. See the emergency response cards for hydrochloric acid and thiodiglycol.
  • Contact with metals may evolve flammable hydrogen gas.
  • When heated, vapors may form explosive mixtures with air, presenting an explosion hazard indoors, outdoors, and in sewers.
  • Containers may explode when heated.
  • Mustard-lewisite is combustible.
  • The agent may burn but does not ignite readily.
  • Fire may produce irritating, corrosive, and/or toxic gases.
  • For small fires, use dry chemical, carbon dioxide, or water spray.
  • For large fires, use dry chemical, carbon dioxide, alcohol-resistant foam, or water spray. Move containers from the fire area if it is possible to do so without risk to personnel. Dike fire control water for later disposal; do not scatter the material.
  • Avoid methods that will cause splashing or spreading.
  • For fire involving tanks or car/trailer loads, fight the fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after the fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tanks. Always stay away from tanks engulfed in fire.
  • Runoff from fire control or dilution water may be corrosive and/or toxic, and it may cause pollution.
  • If the situation allows, control and properly dispose of run-off (effluent).
  • If a tank, rail car, or tank truck is involved in a fire, isolate it for 0.5 mi (800 m) in all directions; also, consider initial evacuation for 0.5 mi (800 m) in all directions.
  • Small spills (involving the release of approximately 52.83 gallons (200 liters) or less), when mustard-lewisite or HL is used as a weapon
  • First isolate in all directions: 100 ft (30 m).
  • Then protect persons downwind during the day: 0.1 mi (0.2 km).
  • Then protect persons downwind during the night: 0.2 mi (0.4 km).
  • Large spills (involving quantities greater than 52.83 gallons (200 liters)), when mustard-lewisite or HL is used as a weapon
  • First isolate in all directions: 300 ft (90 m).
  • Then protect persons downwind during the day: 0.6 mi (1.0 km).
  • Then protect persons downwind during the night: 1.1 mi (1.8 km).
  • Vapors are heavier than air. They will spread along the ground and collect and stay in poorly-ventilated, low-lying, or confined areas (e.g., sewers, basements, tanks).
  • Hazardous concentrations may develop quickly in enclosed, poorly-ventilated, or low-lying areas. Keep out of these areas. Stay upwind.
  • Due to its low freezing point, the mixture remains a liquid in cold weather and at high altitudes.
  • The mixture with the lowest freezing point consists of 63% lewisite and 37% mustard.
  • Health: Not established/determined
  • Flammability: Not established/determined
  • Reactivity: Not established/determined
  • Special:
  • OSHA: Not established/determined
  • NIOSH: Not established/determined
References are provided for the convenience of the reader and do not imply endorsement by NIOSH.
  • AIR MATRIX
    No references were identified for this sampling matrix for this agent.
  • OTHER
    No references were identified for this sampling matrix for this agent.
  • SOIL MATRIX
    No references were identified for this sampling matrix for this agent.
  • SURFACES
    No references were identified for this sampling matrix for this agent.
  • WATER
    No references were identified for this sampling matrix for this agent.

Signs/Symptoms

Following exposure to mustard-lewisite mixture, the effects of lewisite exposure are seen within seconds to minutes; the effects of sulfur mustard are more delayed. The time course for symptoms falls between the time courses of the two individual agents but is closer to the time course for lewisite. Respiratory exposure to vapor produces immediate irritation of the upper, then the lower, respiratory tract; with increasing doses, inflammation is more severe and progresses deeper into the respiratory tract. Eye exposure produces immediate pain, followed by swelling and injury to the eye within one hour. Skin (dermal) exposure produces immediate stinging pain, followed by reddening (erythema) within 30 minutes; blistering is delayed for hours, but it appears earlier than with exposure to pure sulfur mustard. Following ingestion exposure, there is a 15- to 20-minute symptom-free (latent) period, followed by severe pain and vomiting.

Mustard-lewisite has properties of both sulfur mustard and lewisite. It causes blisters (is a vesicant) and binds to DNA and damages rapidly dividing cells (is an alkylating agent). The alkylating properties of mustard-lewisite make it particularly toxic to the blood-forming tissues (e.g., the bone marrow). Whole-body (systemic) absorption of mustard-lewisite mixture may result in bone marrow suppression and an increased risk for fatal complicating infections. The rate of detoxification of mustard-lewisite in the body is very slow, and repeated exposure is likely to cause a build-up of the agent in the body.

  • Mild to moderate: Immediate stinging and burning sensation, tear production (lacrimation), spasmodic blinking (blepharospasm), fluid accumulation (edema) in membranes and eyelids, painful sensitivity to light (photophobia), inflammation of the membranes of the eye (conjunctivitis) and of the cornea, temporary loss of eyesight.
  • Severe: Permanent loss of sight due to damage to the cornea.
  • Severe stomach pain, vomiting (emesis), bloody stools (melena).
  • Whole-body (systemic) effects may occur. See Inhalation Exposure.
  • Mild to moderate: Extreme irritation of the mucous membranes, burning nasal pain, nosebleed (epistaxis), sinus pain, inflammation of the voice box (laryngitis), cough, and difficulty breathing or shortness of breath (dyspnea).
  • Severe: Accumulation of fluid in the lungs (pulmonary edema).
  • Systemic effects include weakness (malaise), restlessness, subnormal body temperature (hypothermia), salivation, nausea, vomiting (emesis), diarrhea (watery or bloody), inflammation of the lining of the stomach and intestines (gastroenteritis), loss of fluid from the bloodstream resulting in low blood pressure (hypotension) and shock, and death.
  • Immediate stinging pain in the skin, irritation, initial graying of the skin followed by reddening (erythema), and delayed blistering (vesication).
  • Whole-body (systemic) effects may occur. See Inhalation Exposure.

Decontamination

The purpose of decontamination is to make an individual and/or their equipment safe by physically removing toxic substances quickly and effectively. Care should be taken during decontamination, because absorbed agent can be released from clothing and skin as a gas. Your Incident Commander will provide you with decontaminants specific for the agent released or the agent believed to have been released.

The following are recommendations to protect the first responders from the release area:

  • Position the decontamination corridor upwind and uphill of the hot zone.
  • The warm zone should include two decontamination corridors. One decontamination corridor is used to enter the warm zone and the other for exiting the warm zone into the cold zone. The decontamination zone for exiting should be upwind and uphill from the zone used to enter.
  • Decontamination area workers should wear appropriate PPE. See the PPE section of this card for detailed information.
  • A solution of detergent and water (which should have a pH value of at least 8 but should not exceed a pH value of 10.5) should be available for use in decontamination procedures. Soft brushes should be available to remove contamination from the PPE.
  • Labeled, durable 6-mil polyethylene bags should be available for disposal of contaminated PPE.

The following methods can be used to decontaminate an individual:

  • Decontamination of First Responder:
    • Begin washing PPE of the first responder using soap and water solution and a soft brush. Always move in a downward motion (from head to toe). Make sure to get into all areas, especially folds in the clothing. Wash and rinse (using cold or warm water) until the contaminant is thoroughly removed.
    • Remove PPE by rolling downward (from head to toe) and avoid pulling PPE off over the head. Remove the SCBA after other PPE has been removed.
    • Place all PPE in labeled durable 6-mil polyethylene bags.
  • Decontamination of Patient/Victim:
    • Remove the patient/victim from the contaminated area and into the decontamination corridor.
    • Remove all clothing (at least down to their undergarments) and place the clothing in a labeled durable 6-mil polyethylene bag.
    • Thoroughly wash and rinse (using cold or warm water) the contaminated skin of the patient/victim using a soap and water solution. Be careful not to break the patient/victim’s skin during the decontamination process, and cover all open wounds.
    • Cover the patient/victim to prevent shock and loss of body heat.
    • Move the patient/victim to an area where emergency medical treatment can be provided.

First Aid

Rapid decontamination (within minutes of exposure) is the only way to limit injury. Initial treatment is primarily supportive.

There is no antidote for mustard toxicity. British Anti-Lewisite (BAL; dimercaprol) binds to the arsenic in lewisite to decrease the toxicity of this agent. BAL is given by intramuscular (IM) injection as an antidote for whole-body (systemic) health effects of lewisite, but it has no effect on local lesions of the skin, eyes, or airways. Side effects from BAL are known; administration of BAL should occur only in a hospital setting. Note: BAL should not be administered to persons with a peanut allergy.

  • Immediately remove the patient/victim from the source of exposure.
  • Immediately wash eyes with large amounts of tepid water for at least 15 minutes.
  • Eyes must be decontaminated within minutes after exposure to limit injury.
  • Do not cover eyes with bandages.
  • Seek medical attention immediately.
  • Immediately remove the patient/victim from the source of exposure.
  • Ensure that the patient/victim has an unobstructed airway.
  • Do not induce vomiting (emesis).
  • Administer nothing by mouth (NPO).
  • Seek medical attention immediately.
  • Immediately remove the patient/victim from the source of exposure.
  • Evaluate respiratory function and pulse.
  • Ensure that the patient/victim has an unobstructed airway.
  • If shortness of breath occurs or breathing is difficult (dyspnea), administer oxygen.
  • Assist ventilation as required. Always use a barrier or bag-valve-mask device.
  • If breathing has ceased (apnea), provide artificial respiration.
  • Monitor for and treat spasmodic narrowing of the large airways (bronchospasm), if it occurs.
  • If evidence of shock or low blood pressure (hypotension) is observed, begin intravenous (IV) fluid administration.
  • Seek medical attention immediately.
  • Immediately remove the patient/victim from the source of exposure.
  • See the decontamination section for patient/victim decontamination procedures.
  • Skin must be decontaminated within minutes after exposure to limit injury.
  • Persons exposed to mustard-lewisite mixture will seldom be received for medical treatment in time to prevent tissue damage.
  • Treat any chemical burns with standard burn therapy.
  • Seek medical attention immediately.
See ATSDR Medical Management Guidelines for Acute Chemical Exposures, Blister Agents Lewisite and Mustard-Lewisite Mixture, https://www.atsdr.cdc.gov/MHMI/mmg163.pdf for detailed recommendations.

Long-Term Implications

Fluid and electrolyte balance should be monitored and restored if abnormal. Gastric lavage is contraindicated following ingestion of this agent due to the risk of perforation of the esophagus or upper airway.

Whole-body (systemic) absorption of mustard-lewisite mixture may induce bone marrow suppression and an increased risk for fatal complicating infections. Chronic respiratory and eye conditions may persist following exposure to large amounts of mustard-lewisite mixture.

Information regarding mustard-lewisite mixture’s potential as a carcinogen, developmental toxin, or reproductive toxin, from chronic or repeated exposure is inconclusive. However, because of mustard-lewisite mixture’s sulfur mustard content, chronic or repeated exposure may lead to respiratory system or skin cancers. Chronic or repeated exposure to mustard-lewisite mixture may cause immune system sensitization and chronic lung impairment characterized by cough, shortness of breath, and chest pain.


On-Site Fatalities

  • Consult with the Incident Commander regarding the agent dispersed, dissemination method, level of PPE required, location, geographic complications (if any), and the approximate number of remains.
  • Coordinate responsibilities and prepare to enter the scene as part of the evaluation team along with the FBI HazMat Technician, local law enforcement evidence technician, and other relevant personnel.
  • Begin tracking remains using waterproof tags.
  • Wear PPE until all remains are deemed free of contamination.
  • Establish a preliminary (holding) morgue.
  • Gather evidence, and place it in a clearly labeled impervious container. Hand any evidence over to the FBI.
  • Remove and tag personal effects.
  • Perform a thorough external evaluation and a preliminary identification check.
  • See the Decontamination section for decontamination procedures.
  • Decontaminate remains before they are removed from the incident site.
See Guidelines for Mass Fatality Management During Terrorist Incidents Involving Chemical Agents, U.S. Army Soldier and Biological Chemical Command (SBCCOM), November, 2001 for detailed recommendations.

Occupational Exposure Limits

  • NIOSH REL:
    • Not established/determined
  • OSHA PEL:
    • Not established/determined
  • ACGIH TLV:
    • Not established/determined
  • NIOSH IDLH: Not established/determined
  • DOE TEEL:
    • TEEL-0: Not established/determined
    • TEEL-1: Not established/determined
    • TEEL-2: Not established/determined
    • TEEL-3: Not established/determined
  • AIHA ERPG:
    • ERPG-1: Not established/determined
    • ERPG-2: Not established/determined
    • ERPG-3: Not established/determined

Acute Exposure Guidelines

Acute Exposure Guidelines
5 min 10 min 30 min 1 hr 4 hr 8 hr
AEGL 1
(discomfort, non-disabling) – mg/m3
Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined
AEGL 2
(irreversible or other serious, long-lasting effects or impaired ability to escape) – mg/m3
Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined
AEGL 3
(life-threatening effects or death) – mg/m3
Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined
See AEGL values for sulfur mustard and lewisite.

Decontamination (Environment and Equipment)

The following methods can be used to decontaminate the environment/spillage disposal:

  • Do not touch or walk through the spilled agent if at all possible. However, if you must, personnel should wear the appropriate PPE during environmental decontamination. See the PPE section of this card for detailed information.
  • Keep combustibles (e.g., wood, paper, and oil) away from the spilled agent.
  • Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact the spilled agent.
  • Do not direct water at the spill or the source of the leak.
  • Stop the leak if it is possible to do so without risk to personnel, and turn leaking containers so that gas rather than liquid escapes.
  • Prevent entry into waterways, sewers, basements, or confined areas.
  • Isolate the area until gas has dispersed.
  • Ventilate the area.

Agents can seep into the crevices of equipment making it dangerous to handle. The following methods can be used to decontaminate equipment:

  • Not established/determined

Agent Properties

  • Chemical Formula:
    Not established/determined
  • Aqueous solubility:
    Slightly soluble based on solubility’s of lewisite and sulfur mustard individually
  • Boiling Point:
    Indefinite, but below 374°F (190°C)
  • Density:
    Liquid: 1.66 g/cm3 at 68°F (20°C)
    Vapor: 6.5 (air = 1)
  • Flammability:
    Combustible
  • Flashpoint:
    Not established/determined
  • Ionization potential:

    Not established/determined

  • Log Kbenzene-water:
    Not established/determined
  • Log Kow (estimated):
    Not established/determined
  • Melting Point:
    Purified mix: 13°F (-25.4°C)
    Typical production batch: -43.6°F (-42°C)
  • Molecular Mass:
    Lewisite: 207.32
    Sulfur mustard: 159.08
  • Soluble In:

    Not established/determined

  • Specific Gravity:
    1.60 at 68°F (20°C)
  • Vapor Pressure:
    0.248 at 68°F (20°C)
  • Volatility:
    240 mg/m3 at 12°F (-11°C)
    2,730 mg/m3 at 68°F (20°C)
    310,270 mg/m3 at 104°F (40°C)

Hazardous Materials Warning Labels/Placards

  • Shipping Name:
    Toxic liquids, organic, n.o.s.
  • Identification Number:
    2810 (Guide 153)
  • Hazardous Class or Division:
    6.1
  • Subsidiary Hazardous Class or Division:
  • Label:
    Poison (Toxic)
    PG III
  • Placard Image:
    dot_class6_pgiii dot_class6_poison dot_class6_toxic

Trade Names and Other Synonyms

Who to Contact in an Emergency

In the event of a poison emergency, call the poison center immediately at 1-800-222-1222. If the person who is poisoned cannot wake up, has a hard time breathing, or has convulsions, call 911 emergency services.

For information on who to contact in an emergency, see the CDC website at emergency.cdc.gov or call the CDC public response hotline at (888) 246-2675 (English), (888) 246-2857 (Español), or (866) 874-2646 (TTY).

Important Notice

The user should verify compliance of the cards with the relevant STATE or TERRITORY legislation before use. NIOSH, CDC 2003.