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Chemical Datasheet


6.1 - Poison Inhalation Hazard
Chemical Identifiers | Hazards | Response Recommendations | Physical Properties | Regulatory Information | Alternate Chemical Names

Chemical Identifiers

CAS Number - Chemical Abstracts Service registry number. Unique identification number assigned to this chemical by the American Chemical Society.

UN/NA Number - The United Nations-North America number (also called UN number or DOT number). 4-digit number identifying an individual chemical or group of chemicals with similar characteristics. Required on shipping papers; often shown on placards or labels. This numbering system was developed by the U.S. Department of Transportation, and then became the UN standard system for classifying hazardous materials.

DOT Hazard Label - U.S. Department of Transportation hazard warning label for the chemical (such as flammable liquid or corrosive). This label must be displayed on shipped packages, railroad tank cars, and tank trucks according to specifications described in 49 CFR 172.

CHRIS Code - 3-letter code used by the U.S. Coast Guard to identify individual chemicals included in its CHRIS (Chemical Hazards Response Information System) manual.

NFPA 704 - Text description of the diamond-shaped placard, which contains codes indicating the level of the chemical's health, flammability, and instability hazards, along with special hazards such as water- and air-reactivity. See a guide to the NFPA diamond.

General Description - Brief description of the chemical's general appearance, behavior, and hazardousness.

List of data sources.
CAS Number UN/NA Number DOT Hazard Label CHRIS Code
  • 7784-34-1   (ARSENIC TRICHLORIDE)
  • Poison Inhalation Hazard
NFPA 704
Diamond Hazard Value Description
3 0
Blue Health 3 Can cause serious or permanent injury.
Red Flammability 0 Will not burn under typical fire conditions.
Yellow Instability 0 Normally stable, even under fire conditions.
White Special
(NFPA, 2010)
General Description
A colorless to yellow oily fuming liquid. It is irritating to the skin, eyes, and mucous membranes. Very toxic by inhalation and ingestion.


Reactivity Alerts - Special alerts if the chemical is especially reactive (see list of reactivity alerts).

Air & Water Reactions - Special alerts if the chemical reacts with air, water, or moisture.

Fire Hazard - Description of the chemical's fire hazards (such as flammability, explosion risk, or byproducts that may evolve if the chemical is burned).

Health Hazard - Description of the chemical's health hazards (such as toxicity, flammability, or corrosivity).

Reactivity Profile - Description of the chemical's potential reactivity with other chemicals, air, and water. Also includes any other intrinsic reactive hazards (such as polymerizable or peroxidizable).

Reactive Groups - List of reactive groups that the chemical is assigned to, based on its known chemistry. Reactive groups are categories of chemicals that react in similar ways because their chemical structures are similar. Reactive groups are used to predict reactivity when you add a chemical to MyChemicals. Read more about reactive groups.

Potentially Incompatible Absorbents - Absorbents are products that can be used to soak up liquids from spills. However, some absorbents can react with particular chemicals (that is, they are incompatible), so caution should be used in selecting the correct absorbent for your situation. This section provides a list of potentially incompatible absorbents that have been known to react with liquids assigned to one or more of the reactive groups listed on this datasheet. Read more about absorbents, including situations to watch out for.

List of data sources.
Reactivity Alerts
Air & Water Reactions
Fumes in air. Reacts with water to form hydrochloric acid and As(OH)3.
Fire Hazard
When in contact with active metals such as arsenic, iron, aluminum, zinc, or when heated to decomposition, it emits highly toxic fumes of arsenic. Upon contact with water hydrogen chloride is produced. Water causes it to decompose to yield arsenic acid and hydrochloric acid. Avoid active metals such as arsenic, iron, aluminum, zinc, decomposed by water to form arsenic hydroxide and hydrogen chloride. Avoid air, ultraviolet light. Hazardous polymerization may not occur. (EPA, 1998)
Health Hazard
It can cause death. In acute exposures, it is extremely toxic and caustic, owing not only to the poisonous nature of arsenic, but also to the release of hydrochloric acid in the presence of water. Exposure to the skin causes local irritation and blisters. Inhalation or ingestion causes hemorrhagic gastroenteritis resulting in loss of fluids and electrolytes, collapse, shock and death. Chronic poisoning can lead to peripheral nerve damage, skin conditions, liver damage and it has been implicated in the induction of skin and lung cancer. The fatal human dose is 70-180 mg depending on the weight of the victim. (EPA, 1998)
Reactivity Profile
When ARSENIC CHLORIDE is heated to decomposition or on contact with mineral acids, it emits highly toxic fumes of hydrogen chloride and of metallic arsenic. Explodes with Na, K, and Al on impact [Sax, 9th ed., 1996, p. 275]. The interaction of hexafluoroisopropylideneaminolithium with a range of chlorinated and /or fluorinated derivatives of arsenic, boron, phosphorus, silicon, and sulfur yielded a violently exothermic reaction.
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation - Isolation and evacuation distance recommendations from the Emergency Response Guidebook (ERG).

Firefighting - Response recommendations if the chemical is on fire (or near a fire).

Non-Fire Response - Response recommendations if the chemical isn't on fire (or near a fire).

Protective Clothing - Recommendations for protective gear.

Dupont Tychem® Suit Fabrics - A table of normalized breakthrough times for DuPont Tychem suit fabrics for the chemical, if available.

First Aid - Recommended first aid treatment for people exposed to the chemical.

List of data sources.
Isolation and Evacuation
Excerpt from GUIDE 157 [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

As an 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: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1560 datasheet.

FIRE: If tank, rail car or tank truck 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, 2012)
Wear positive pressure breathing apparatus and special protective clothing. Move container from fire area if you can do so without risk. Fight fire from maximum distance. Dike fire control water for later disposal; do not scatter the material.

This compound is not flammable. Extinguish with dry chemical, carbon dioxide, water spray, fog, or foam. (EPA, 1998)
Non-Fire Response
Excerpt from GUIDE 157 [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. A vapor suppressing foam may be used to reduce vapors. DO NOT GET WATER INSIDE CONTAINERS. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Prevent entry into waterways, sewers, basements or confined areas.

SMALL SPILL: Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal. (ERG, 2012)
Protective Clothing
Safety goggles and face shield; acid-type canister gas mask; rubber gloves; protective clothing. (USCG, 1999)
DuPont Tychem® Suit Fabrics
Tychem® Fabric Legend
QC = Tychem QC
SL = Tychem SL
TF = Tychem F
TP = Tychem ThermoPro
C3 = Tychem CPF 3
BR = Tychem BR
LV = Tychem LV
RC = Tychem Responder® CSM
TK = Tychem TK
RF = Tychem Reflector®
Testing Details
Permeation data obtained per ASTM F739. Normalized breakthrough times (the time at which the permeation rate is equal to 0.1 µg/cm2/min) reported in minutes. All liquid 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.
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QC SL TF TP C3 BR LV RC TK RF
Arsenic trichloride 7784-34-1 Liquid 38 38
A blank cell indicates the fabric has not been tested. The fabric may or may not offer barrier.

Special Warnings from DuPont

  1. Serged and bound seams are degraded by some hazardous liquid chemicals, such as strong acids, and should not be worn when these chemicals are present.
  2. CAUTION: This information is based upon technical data that DuPont believes to be reliable. It is subject to revision as additional knowledge and experience are gained. DuPont makes no guarantee of results and assumes no obligation or liability...
    ... in connection with this information. It is the user's responsibility to determine the level of toxicity and the proper personal protective equipment needed. The information set forth herein 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. 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. Please contact DuPont for specific data. 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, we make 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 or technical information of DuPont or others covering any material or its use.

(DuPont, 2013)

First Aid
Warning: Effects usually appear within 30 minutes of exposure but may be delayed for several hours. Caution is advised.

Signs and Symptoms of Acute Arsenous Trichloride Exposure: Dehydration, intense thirst, vomiting, severe abdominal pain, and diarrhea are among the first signs and symptoms of acute arsenous trichloride exposure. Hypotension (low blood pressure) and tachycardia (rapid heart rate) are common. Headache, conjunctivitis (red, inflamed eyes), runny nose, and lacrimation (tearing) may also be seen. Garlic odor to the breath and feces may be noted. Cardiovascular signs include shock, ventricular fibrillation, tachycardia, and other cardiac abnormalities. Pulmonary edema may occur. Altered mental status, seizures, and delirium are further complications of acute arsenous trichloride exposure. Intense muscular cramping is common. Contact with airborne dust can result in the release of hydrochloric acid and is generally accompanied by irritation of exposed skin, eyes, and mucous membranes.

Emergency Life-Support Procedures: Acute exposure to arsenous trichloride 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 arsenous trichloride.
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 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 arsenous trichloride.
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 oxygen or other respiratory support.
3. Remove contaminated clothing as soon as possible.
4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.
5. Wash exposed skin areas THOROUGHLY with soap and water.
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 oxygen or other respiratory support.
2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
3. DO NOT induce vomiting.
4. Give the victims water or milk: children up to 1 year old, 125 mL (4 oz or 1/2 cup); children 1 to 12 years old, 200 mL (6 oz or 3/4 cup); adults, 250 mL (8 oz or 1 cup). Water or milk should be given only if victims are conscious and alert.
5. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water.
6. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults.
7. RUSH to a health care facility. (EPA, 1998)

Physical Properties

This section contains physical properties, flammability limits, and toxic thresholds for this chemical (see definitions of each property). More property data is available for common chemicals.

See also the Levels of Concern guide for information on AEGLs, ERPGs, PACs, and IDLH values.

List of data sources.
Chemical Formula:
  • AsCl3
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: 3.2 ° F (EPA, 1998)
Vapor Pressure: 10 mm Hg at 74.3 ° F (EPA, 1998)
Vapor Density (Relative to Air): 6.25 (EPA, 1998)
Specific Gravity: 2.156 at 77.0 ° F (USCG, 1999)
Boiling Point: 266.4 ° F at 760.0 mm Hg (USCG, 1999)
Molecular Weight: 181.28 (EPA, 1998)
Water Solubility: data unavailable
IDLH: 5 mg/m3 as arsenic, suspected human carcinogen. (NIOSH, 2003)

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Arsenous trichloride (7784-34-1) 0.91 mg/m3 10 mg/m3 240 mg/m3
(SCAPA, 2012)

Regulatory Information

This section contains regulatory information from the Title III Consolidated List of Lists (see details about each regulatory field).

List of data sources.
Regulatory Name CAS Number/
313 Category Code
CAA 112(r)
Arsenic Compounds N020 & 313
Arsenous trichloride 7784-34-1 500 1 1 313c 15000

(EPA List of Lists, 2012)

Alternate Chemical Names

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