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Chemical Datasheet

STYRENE MONOMER, STABILIZED

3 - Flammable liquid

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 100-42-5   (STYRENE MONOMER)
  • 2055
  • Flammable Liquid
  • STY
NIOSH Pocket Guide International Chem Safety Card
Styrene
  • STYRENE
NFPA 704
Diamond Hazard Value Description
3
2 2
Blue Health 2 Can cause temporary incapacitation or residual injury.
Red Flammability 3 Can be ignited under almost all ambient temperature conditions.
Yellow Instability 2 Readily undergoes violent chemical changes at elevated temperatures and pressures.
White Special
(NFPA, 2010)
General Description
A clear colorless to dark liquid with an aromatic odor. Vapors heavier than air and irritating to the eyes and mucous membranes. Subject to polymerization. If the polymerization takes place inside a closed container, the container may rupture violently. Less dense than water and insoluble in water. Used to make plastics, paints, and synthetic rubber.

Hazards

Reactivity Alerts
Air & Water Reactions
Highly flammable. Insoluble in water.
Fire Hazard
Behavior in Fire: Vapor is heavier than air and may travel considerable distance to a source of ignition and flash back. At elevated temperatures such as in fire conditions, polymerization may take place which may lead to container explosion. (USCG, 1999)
Health Hazard
Moderate irritation of eyes and skin. High vapor concentrations cause dizziness, drunkeness, and anesthesia. (USCG, 1999)
Reactivity Profile
STYRENE MONOMER is a colorless, oily liquid, moderately toxic, flammable. A storage hazard above 32°C, involved in several industrial explosions caused by violent, exothermic polymerization [Bond, J., Loss Prev. Bull., 1985, (065), p. 25]. Polymerization becomes self-sustaining above 95°C [MCA SD-37, 1971]. Presence of an inhibitor lessens but does not eliminate the possibility of unwanted polymerization. Violent polymerization leading to explosion may be initiated by peroxides (e.g., di-tert-butyl peroxide, dibenzoyl peroxide), butyllithium, azoisobutyronitrile. Reacts violently with strong acids (sulfuric acid, oleum, chlorosulfonic acid), strong oxidizing agents [Lewis, 3rd ed., 1993, p. 1185]. Reacts with oxygen above 40°C to form explosive peroxide [Barnes, C. E. et al., J. Amer. Chem. Soc., 1950, 72, p. 210]. Oxidizes readily in air to form unstable peroxides that may explode spontaneously [Bretherick 1979 p.151-154, 164]. Mixing styrene in equal molar portions with any of the following substances in a closed container caused the temperature and pressure to increase: chlorosulfonic acid, oleum, and sulfuric acid [NFPA 1991].
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.

Response Recommendations

Isolation and Evacuation
Excerpt from ERG Guide 128P [Flammable Liquids (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, 2016)
Firefighting
Excerpt from ERG Guide 128P [Flammable Liquids (Water-Immiscible)]:

CAUTION: All these products have a very low flash point: Use of water spray when fighting fire may be inefficient. CAUTION: For mixtures containing alcohol or polar solvent, alcohol-resistant foam may be more effective.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam.

LARGE FIRE: Water spray, fog or regular foam. Do not use straight streams. Move containers from fire area if you can do it without risk.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. For massive fire, use unmanned hose holders or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2016)
Non-Fire Response
Excerpt from ERG Guide 128P [Flammable Liquids (Water-Immiscible)]:

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 or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2016)
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. (NIOSH, 2016)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP BR RC TK RF
Styrene (>95%) 100-42-5 Liquid 16 >480 >480 >480 >480 >480 >480 >480
> indicates greater than.
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...

(DuPont, 2018)

First Aid
EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

Physical Properties

Chemical Formula:
  • C8H8
Flash Point: 88 ° F (NTP, 1992)
Lower Explosive Limit (LEL): 1.1 % (NTP, 1992)
Upper Explosive Limit (UEL): 6.1 % (NTP, 1992)
Autoignition Temperature: 914 ° F (USCG, 1999)
Melting Point: -24 to -23 ° F (NTP, 1992)
Vapor Pressure: 4.3 mm Hg at 59 ° F ; 9.5 mm Hg at 86° F; 10 mm Hg at 95° F (NTP, 1992)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 0.906 at 68 ° F (USCG, 1999)
Boiling Point: 293 to 295 ° F at 760 mm Hg (NTP, 1992)
Molecular Weight: 104.16 (NTP, 1992)
Water Solubility: less than 1 mg/mL at 66° F (NTP, 1992)
Ionization Potential: 8.40 eV (NIOSH, 2016)
IDLH: 700 ppm (NIOSH, 2016)

AEGLs (Acute Exposure Guideline Levels)

Interim AEGLs for Styrene (100-42-5)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes 20 ppm 230 ppm 1900 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
30 minutes 20 ppm 160 ppm 1900 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
60 minutes 20 ppm 130 ppm 1100 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
4 hours 20 ppm 130 ppm 340 ppm
8 hours 20 ppm 130 ppm 340 ppm
Lower Explosive Limit (LEL) = 9000 ppm
1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
Level of Distinct Odor Awareness = 0.54 ppm
(NAC/NRC, 2017)

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Styrene (100-42-5) 50 ppm star-in-circle icon indicates that odor should be detectable near ERPG-1. 250 ppm 1000 ppm
star-in-circle icon indicates that odor should be detectable near ERPG-1.
(AIHA, 2016)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Styrene (100-42-5) 20 ppm 130 ppm 1100 ppm 1-flame icon indicates value is 10-49% of LEL. LEL = 9000 ppm
1-flame icon indicates value is 10-49% of LEL.
(DOE, 2016)

Regulatory Information

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
Styrene 100-42-5 1000 pounds 313

(EPA List of Lists, 2015)

DHS Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names