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Chemical Datasheet

LEWISITE

Chemical Identifiers | Hazards | Response Recommendations | Physical Properties | Regulatory Information | Alternate Chemical Names

Chemical Identifiers

The Chemical Identifier fields include common identification numbers, the NFPA diamond U.S. Department of Transportation hazard labels, and a general description of the chemical. The information in CAMEO Chemicals comes from a variety of data sources.
CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 541-25-3
none data unavailable none
NIOSH Pocket Guide International Chem Safety Card
none none
NFPA 704
data unavailable
General Description
A chemical warfare blister agent. Very toxic. When pure, a colorless oily liquid solidifying at -13°C. Impurities cause colors ranging from brown to violet. Faint odor of geranium. Irritating to the eyes and mucous membranes at concentrations below the threshold of odor. Produces severe vesication (blistering) even through rubber (Merck); absorbed through the skin to produce seven systemic effects. Antidote: dimercaprol (British Anti-Lewisite). Prolonged exposure of container to fire or intense heat may result in violent rupturing and rocketing of container.

Hazards

The Hazard fields include special hazard alerts air and water reactions, fire hazards, health hazards, a reactivity profile, and details about reactive groups assignments and potentially incompatible absorbents. The information in CAMEO Chemicals comes from a variety of data sources.
Reactivity Alerts
none
Air & Water Reactions
Slowly decomposed by water.
Fire Hazard
For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

(Non-Specific -- Arsenic Compound, Liquid, n.o.s.) Container may explode in heat of fire. Fire may produce irritating and poisonous gases. Hydrolyzed by alkalies; neutralized by sodium hypochlorite. (EPA, 1998)
Health Hazard
For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Highly toxic by all routes of exposure. Lethal dose in humans is 6 ppm (inhalation), 20 mg/kg (skin). Eye injury below 300 mg-min./m3. It is a blister agent, cell irritant, and systemic poison. (EPA, 1998)
Reactivity Profile
LEWISITE is hydrolyzed by alkalis. It is neutralized or inactivated as a vesicant by sodium hypochlorite [EPA, 1998].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below. More info about absorbents, including situations to watch out for...

Response Recommendations

The Response Recommendation fields include isolation and evacuation distances, as well as recommendations for firefighting, non-fire response, protective clothing, and first aid. The information in CAMEO Chemicals comes from a variety of data sources.
Isolation and Evacuation
For initial isolation and protective action distances for chemical warfare blister agents see the Chemical Warfare Agents table in the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)
Firefighting
For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

(Non-Specific -- Arsenic Compound, Liquid, n.o.s.) Wear special protective clothing and positive pressure breathing apparatus.

(Non-Specific -- Arsenic Compound, Liquid, n.o.s.) Extinguish with dry chemical, carbon dioxide, water spray, or foam. Use water spray, fog, or foam for large fires. (EPA, 1998)
Non-Fire Response
For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)
Protective Clothing
For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)
DuPont Tychem® Suit Fabrics
Tychem® Fabric Legend
QS = Tychem 2000 SFR
QC = Tychem 2000
SL = Tychem 4000
C3 = Tychem 5000
TF = Tychem 6000
TP = Tychem 6000 FR
RC = Tychem RESPONDER® CSM
TK = Tychem 10000
RF = Tychem 10000 FR
Testing Details
The fabric permeation data was generated for DuPont by a third party laboratory. Permeation data for industrial chemicals is obtained per ASTM F739. Normalized breakthrough times (the time at which the permeation rate exceeds 0.1 μg/cm2/min) are reported in minutes. All chemicals have been tested between approximately 20°C and 27°C unless otherwise stated. All chemicals have been tested at a concentration of greater than 95% unless otherwise stated.
Chemical warfare agents (Lewisite, Sarin, Soman, Sulfur Mustard, Tabun and VX Nerve Agent) have been tested at 22°C and 50% relative humidity per military standard MIL-STD-282. "Breakthrough time" for chemical warfare agents is defined as the time when the cumulative mass which permeated through the fabric exceeds the limit in MIL-STD-282 [either 1.25 or 4.0 μg/cm2].
A Caution from DuPont
This information is based upon technical data that DuPont believes to be reliable on the date issued. It is subject to revision as additional knowledge and experience are gained. The information reflects laboratory performance of fabrics, not complete garments, under controlled conditions. It is intended for informational use by persons having technical skill for evaluation under their specific end-use conditions, at their own discretion and risk. It is the user's responsibility to determine the level of toxicity and the proper personal protective equipment needed. Anyone intending to use this information should first verify that the garment selected is suitable for the intended use. In many cases, seams and closures have shorter breakthrough times and higher permeation rates than the fabric. If fabric becomes torn,abraded or punctured, or if seams or closures fail, or if attached gloves, visors, etc. are damaged, end user should discontinue use of garment to avoid potential exposure to chemical. Since conditions of use are outside our control, DuPont makes no warranties, express or implied, including, without limitation, no warranties of merchantability or fitness for a particular use and assume no liability in connection with any use of this information. This information is not intended as a license to operate under or a recommendation to infringe any patent, trademark or technical information of DuPont or others covering any material or its use.
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Lewisite (L), FINABEL 0.7.C 541-25-3 Liquid >155⁸ >155⁸
Lewisite (L), MIL-STD-282 (10 g/m2) 541-25-3 Liquid >360⁸ 120⁸ >480⁸ >480⁸ >480⁸
Lewisite (L), MIL-STD-282 (100 g/m2) 541-25-3 Liquid 360⁸ 360⁸ 120⁸ >480⁸ 120⁸
> indicates greater than.
⁸ indicates actual breakthrough time; normalized breakthrough time is not available.

Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...

...Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments are designed and tested to help reduce burn injury during escape from a flash fire. Users of Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments should not knowingly enter an explosive environment. Tychem® garments with attached socks must be worn inside protective outer footwear and are not suitable as outer footwear. These attached socks do not have adequate durability or slip resistance to be worn as the outer foot covering.

(DuPont, 2024)

First Aid
For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Warning: Lewisite vapors are extremely toxic. Inhalation of high concentrations may be fatal in as little as 10 minutes. Serious poisoning may produce symptoms within 30 to 60 minutes, but may also be delayed for a few hours. Lewisite produces an immediate searing sensation in the eye leading to permanent blindness if not decontaminated within one minute following exposure.

Signs and Symptoms of Lewisite Exposure: Signs and symptoms of acute exposure to lewisite may include headache, red staining of the conjunctiva, a garlicky odor of the breath, and pulmonary edema. Lewisite has produced an immediate and strong stinging sensation to the skin, followed by reddening within 30 minutes and blistering after 13 hours. Subnormal body temperature, restlessness, hypotension, and T-wave elevations are occasionally seen. Gastrointestinal symptoms include nausea, vomiting, diarrhea, anorexia, and abdominal pain. Generalized weakness, muscle cramping, red or green colored urine, and jaundice have also been reported.

Emergency Life-Support Procedures: Acute exposure to lewisite may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:
1. Move victims to fresh air. Emergency personnel should avoid self-exposure to lewisite.
2. Evaluate vital signs including pulse and respiratory rate and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Rush to a health care facility.

Dermal/Eye Exposure:
1. Remove victims from exposure. Emergency personnel should avoid self-exposure to lewisite.
2. Evaluate vital signs including pulse and respiratory rate and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support.
3. Remove and isolate contaminated clothing as soon as possible.
4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes. Speed in removing material from the eyes is of extreme importance.
5. Wash exposed skin areas thoroughly with water. Speed in removing material from skin is of extreme importance.
6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
7. Rush to a health care facility.

Ingestion Exposure:
1. Evaluate vital signs including pulse and respiratory rate and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support.
2. DO NOT induce vomiting or attempt to neutralize.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Activated charcoal is of no use.
5. Rush to a health care facility. (EPA, 1998)

Physical Properties

The Physical Property fields include properties such as vapor pressure and boiling point, as well as explosive limits and toxic exposure thresholds The information in CAMEO Chemicals comes from a variety of data sources.

Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
Chemical Formula:
  • ClCHCHAsCl2
Flash Point: None (EPA, 1998)
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: 32°F (EPA, 1998)
Vapor Pressure: 0.395 mmHg at 68°F (EPA, 1998)
Vapor Density (Relative to Air): 7.1 (EPA, 1998) - Heavier than air; will sink
Specific Gravity: 1.888 at 68°F (EPA, 1998) - Denser than water; will sink
Boiling Point: 374°F at 760 mmHg decomposes (EPA, 1998)
Molecular Weight: 207.31 (EPA, 1998)
Water Solubility: data unavailable
Ionization Energy/Potential: data unavailable
IDLH: data unavailable

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for Lewisite 1 (CAS No. 541-25-3), including mixtures with Lewisite 2 (CAS No. 40334-69-8) and Lewisite 3 (CAS No. 40334-70-1)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes NR 1.3 mg/m3 3.9 mg/m3
30 minutes NR 0.47 mg/m3 1.4 mg/m3
60 minutes NR 0.25 mg/m3 0.74 mg/m3
4 hours NR 0.07 mg/m3 0.21 mg/m3
8 hours NR 0.037 mg/m3 0.11 mg/m3
NR = Not recommended due to insufficient data
(NAC/NRC, 2024)

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Chlorovinylarsine dichloride; (Lewisite 1) (541-25-3) 0.023 mg/m3 0.25 mg/m3 0.74 mg/m3
(DOE, 2024)

Regulatory Information

The Regulatory Information fields include information from the U.S. Environmental Protection Agency's Title III Consolidated List of Lists, the U.S. Cybersecurity and Infrastructure Security Agency's Chemical Facility Anti-Terrorism Standards, and the U.S. Occupational Safety and Health Administration's Process Safety Management of Highly Hazardous Chemicals Standard List (see more about these data sources).

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Arsenic Compounds N020 & 313
Lewisite 541-25-3 10 pounds 10 pounds

(EPA List of Lists, 2024)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

RELEASE THEFT SABOTAGE
Chemical of Interest CAS Number Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Lewisite 1; [2-chlorovinyldichloroarsine] 541-25-3 CUM 100 grams CW/CWP

(CISA, 2007)

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names

This section provides a listing of alternate names for this chemical, including trade names and synonyms.