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Chemical Datasheet


3 - Flammable liquid
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
  • 126-99-8   (CHLOROPRENE)
  • Flammable Liquid
NFPA 704
Diamond Hazard Value Description
2 1
Blue Health 2 Can cause temporary incapacitation or residual injury.
Red Flammability 3 Can be ignited under almost all ambient temperature conditions.
Yellow Instability 1 Normally stable but can become unstable at elevated temperatures and pressures.
White Special
(NFPA, 2010)
General Description
PHYSICAL DESCRIPTION: A clear tan liquid mixture. Composed of 50% 2-chloro-1,3-butadiene, which has a slight ethereal odor; and 50% xylene, which has an aromatic hydrocarbon odor. (NTP, 1992)


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
Highly flammable. Insoluble in water.
Fire Hazard
Component 1 is flammable. Component 2 is flammable. (NTP, 1992)
Health Hazard
SYMPTOMS: Symptoms of exposure to component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE) include irritation of skin, eyes and upper respiratory tract; temporary hair loss, nervousness, irritability, dermatitis, conjunctivitis, corneal necrosis, pulmonary edema, central nervous system and respiratory depression; indigestion, asphyxia, severe degenerative changes in the vital organs, especially, liver and kidneys; lowered blood pressure and anemia. Inhalation of high concentrations may cause anesthesia and paralysis of the respiratory tract. Chronic exposure may cause damage to lungs, kidneys, liver, spleen, nervous system, myocardium and defatting of the skin. Symptoms of exposure to component 2 (50%: XYLENE) include nausea, vomiting, fatigue, anemia, headache, dizziness, incoordination, lack of appetite, narcosis, eye, skin and mucous membrane irritation; chest pain, edema, central nervous system depression; gastrointestinal disturbances, burning sensation in mucous membranes; salivation, bloody vomit, emotional lability, slurred speech, ataxia, stupor, coma, visual blurring, tremors, shallow respiration, ventricular irregularities, paralysis, unconsciousness and convulsions.

ACUTE/CHRONIC HAZARDS: Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE) is extremely flammable and reactive. It is a NIOSH carcinogen. It is an irritant by contact or inhalation. When heated to decomposition this compound may release highly toxic fumes of hydrogen chloride and carbon monoxide. Component 2 (50%: XYLENE) is an eye, skin and mucous membrane irritant. It causes narcosis at high concentrations. When heated to decomposition it emits toxic fumes of carbon monoxide and carbon dioxide. (NTP, 1992)
Reactivity Profile
2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE plus XYLENE mixture is sensitive to exposure to air and light. May also be sensitive to heat. Mixtures with water, DMSO, 95% ethanol or acetone should be stable for 24 hours under normal lab conditions. 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE)can react with oxygen to form polymeric peroxides. It is incompatible with peroxides and other oxidizing agents. Attacks some forms of plastics, rubbers and coatings. XYLENE is incompatible with strong oxidizing agents. Attacks some forms of plastics, rubbers and coatings (NTP, 1992).
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

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 128 [Flammable Liquids (Non-Polar / Water-Immiscible)]:

As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet).

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)
Fires involving this mixture can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)
Non-Fire Response
SMALL SPILLS AND LEAKAGE: If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. Then, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

STORAGE PRECAUTIONS: You should protect this chemical from exposure to light. Keep the container tightly closed under an inert atmosphere, and store it in an explosion-proof refrigerator. STORE AWAY FROM SOURCES OF IGNITION. (NTP, 1992)
Protective Clothing
Skin: Wear appropriate personal protective clothing to prevent skin contact.

Eyes: Wear appropriate eye protection to prevent eye contact.

Wash skin: The worker should immediately wash the skin when it becomes contaminated.

Remove: Work clothing that becomes wet should be immediately removed due to its flammability hazard(i.e. for liquids with flash point < 100°F)

Change: No recommendation is made specifying the need for the worker to change clothing after the work shift.

Provide: Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection. Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2003)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
EYES: Check for contact lenses and remove them at once if present. You should then immediately flush eyes with water for 15 minutes. Do not use oil or ointment in eyes. Arrange immediate transportation to a medical facility.

SKIN: You should remove all contaminated clothing and flood skin with water. Wash all affected skin areas thoroughly with soap and water. If symptoms develop, seek medical attention.

INHALATION: If any of your laboratory personnel should inhale this chemical, remove them at once to open air and arrange for immediate transportation to a medical facility.

INGESTION: If the exposed person is convulsing or unconscious, do not attempt first aid. Transport immediately to a hospital emergency room or poison control center. If the victim is conscious, DO NOT INDUCE VOMITING. Transport to a medical facility. (NTP, 1992)

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:
  • C4H5Cl (2-chloro-1,3-butadiene)
  • C8H10 (xylene)
Flash Point: Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE): -4° F; Component 2 (50%: XYLENE): 85° F (NTP, 1992)
Lower Explosive Limit (LEL): 4 % Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE) (NTP, 1992)
Upper Explosive Limit (UEL): 20 % Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE) (NTP, 1992)
Autoignition Temperature: Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE): 977° F; Component 2 (50%: XYLENE): 870° F (NTP, 1992)
Melting Point: data unavailable
Vapor Pressure: 188 mm Hg at 68.0 ° F Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE) (NTP, 1992)
Vapor Density (Relative to Air): Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE): 3.06; Component 2 (50%: XYLENE): 3.7 (NTP, 1992)
Specific Gravity: 0.905 at 66.4 ° F (NTP, 1992)
Boiling Point: data unavailable
Molecular Weight: Component 1 (50%: 2-CHLORO-1,3-BUTADIENE CHLOROBUTADIENE): 88.54; Component 2 (50%: XYLENE): 106.17 (NTP, 1992)
Water Solubility: less than 1 mg/mL at 68.9° F (NTP, 1992)
IDLH: data unavailable

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
Chloroprene; (beta-Chloroprene; Neoprene) (126-99-8) 10 ppm 10 ppm 400 ppm LEL = 19000 ppm
(SCAPA, 2012)

Regulatory Information

This section contains regulatory information from the U.S. Environmental Protection Agency's Title III Consolidated List of Lists and the U.S. Department of Homeland Security's Chemical Facility Anti-Terrorism Standards (see details about each regulatory field).

List of data sources.

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
CAA 112(r)
Chloroprene 126-99-8 100 313

(EPA List of Lists, 2015)

DHS Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

Alternate Chemical Names

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