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Chemical Datasheet

1,2,4-TRIMETHYLBENZENE

3 - Flammable liquid

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 95-63-6   (1,2,4-TRIMETHYLBENZENE)
  • 1993
  • Flammable Liquid
  • TME
NIOSH Pocket Guide International Chem Safety Card
1,2,4-Trimethylbenzene
  • 1,2,4-TRIMETHYLBENZENE
NFPA 704
Diamond Hazard Value Description
2
1 0
Blue Health 1 Can cause significant irritation.
Red Flammability 2 Must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur.
Yellow Instability 0 Normally stable, even under fire conditions.
White Special
(NFPA, 2010)
General Description
A liquid. Flash point near 130°F. Less dense than water and insoluble in water. Vapors irritate eyes, throat, and nose. Used in dyes and pharmaceuticals.

Hazards

Reactivity Alerts
none
Air & Water Reactions
Insoluble in water.
Fire Hazard
Excerpt from 128 Polymerizable warning [Flammable Liquids (Water-Immiscible)]:

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids will float on water. Substance may be transported hot. For hybrid vehicles, 147 Polymerizable warning (lithium ion batteries) or 138 Polymerizable warning (sodium batteries) should also be consulted. If molten aluminum is involved, refer to 169 Polymerizable warning. (ERG, 2020)
Health Hazard
Harmful if inhaled or swallowed. Vapor or mist is irritating to the eyes, mucous membrane and upper respiratory tract. Prolonged contact can cause dermatitis, nausea, headache, dizziness, and narcotic effect. (USCG, 1999)
Reactivity Profile
1,2,4-TRIMETHYLBENZENE is incompatible with the following: Oxidizers, nitric acid (NIOSH, 2022).
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
Excerpt from 128 Polymerizable warning [Flammable Liquids (Water-Immiscible)]:

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, 2020)
Firefighting
Excerpt from 128 Polymerizable warning [Flammable Liquids (Water-Immiscible)]:

CAUTION: The majority of 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. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. For petroleum crude oil, do not spray water directly into a breached tank car. This can lead to a dangerous boil over. 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 master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2020)
Non-Fire Response
Excerpt from 128 Polymerizable warning [Flammable Liquids (Water-Immiscible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from 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, 2020)
Protective Clothing
Excerpt from NIOSH Pocket Guide for 1,2,4-Trimethylbenzene:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

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

Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift. (NIOSH, 2023)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
Excerpt from NIOSH Pocket Guide for 1,2,4-Trimethylbenzene:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: SOAP WASH - If this chemical contacts the skin, wash the contaminated skin with soap and water.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2023)

Physical Properties

Chemical Formula:
  • C9H12
Flash Point: 111°F (USCG, 1999)
Lower Explosive Limit (LEL): 0.9 % (USCG, 1999)
Upper Explosive Limit (UEL): 6.4 % (USCG, 1999)
Autoignition Temperature: 932°F (USCG, 1999)
Melting Point: -47.2°F (USCG, 1999)
Vapor Pressure: 4.9 mmHg (USCG, 1999)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 0.889 (USCG, 1999) - Less dense than water; will float
Boiling Point: 334.4°F at 760 mmHg (USCG, 1999)
Molecular Weight: 120.2 (USCG, 1999)
Water Solubility: 0.006 % (NIOSH, 2023)
Ionization Energy/Potential: 8.27 eV (NIOSH, 2023)
IDLH: data unavailable

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for 1,2,4-Trimethylbenzene (95-63-6)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes 180 ppm 460 ppm NR
30 minutes 180 ppm 460 ppm NR
60 minutes 140 ppm 360 ppm NR
4 hours 90 ppm 230 ppm NR
8 hours 45 ppm 150 ppm NR
NR = Not recommended due to insufficient data
(NAC/NRC, 2023)

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Trimethylbenzene, 1,2,4-; (Pseudocumene) (95-63-6) 140 ppm 360 ppm 480 ppm LEL = 9000 ppm
(DOE, 2018)

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
1,2,4-Trimethylbenzene 95-63-6 313

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names