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Chemical Datasheet
METHACRYLIC ACID |
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Chemical Identifiers
CAS Number |
UN/NA Number |
DOT Hazard Label |
USCG CHRIS Code |
- 79-41-4
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|
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NIOSH Pocket Guide |
International Chem Safety Card |
Methacrylic acid
|
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NFPA 704
General Description
A clear colorless liquid (or low-melting solid) with a pungent odor. Corrosive to metals and tissue. Flash point 170°F. Melting point 61°F. May polymerize exothermically if heated or contaminated. If the polymerization takes place inside a container, the container may rupture violently. Less dense than water. Vapors heavier than air. Used to make plastics.
Hazards
Reactivity Alerts
Air & Water Reactions
Soluble in water.
Fire Hazard
Special Hazards of Combustion Products: Vapor forms explosive mixtures with air. Thermal decomposition produces carbon monoxide and carbon dioxide.
Behavior in Fire: Vapors form explosive mixtures with air. Sealed containers may rupture explosively at elevated temperatures (polymerization). (USCG, 1999)
Health Hazard
INHALATION: Severe irritation to respiratory tract. EYES: Short contact can cause severe damage. SKIN: Causes severe irritation and burns. Ingestion: High hazard - may cause death or permanent injury on short exposure to small quantities. OTHER: May affect blood pressure temporarily. (USCG, 1999)
Reactivity Profile
METHACRYLIC ACID reacts with strong oxidizing agents. Presents a storage hazard: violent exothermic polymerizations leading to explosion can occur spontaneously, particularly at low inhibitor or stabilizer concentrations [Anon., CISHC Chem. Safety Summ., 1979, 50, p. 34; Bond, J., Loss Prev. Bull., 1991, 101, p. 1].
Belongs to the Following Reactive Group(s)
- Acrylates and Acrylic Acids
- Polymerizable Compounds
Potentially Incompatible Absorbents
Use caution: Liquids with this reactive group classification have been
known to react with the
absorbents
listed below.
- Cellulose-Based Absorbents
- Mineral-Based & Clay-Based Absorbents
- Dirt/Earth
Response Recommendations
Isolation and Evacuation
Excerpt from ERG Guide 153

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

[Substances - Toxic and/or Corrosive (Combustible); polymerization hazard]:
SMALL FIRE: Dry chemical, CO2 or water spray.
LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.
FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. 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 in direct contact with flames. (ERG, 2024)
Non-Fire Response
Excerpt from ERG Guide 153

[Substances - Toxic and/or Corrosive (Combustible); polymerization hazard]:
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
Excerpt from NIOSH Pocket Guide for Methacrylic acid:
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: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.
Provide:
• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.
• QUICK DRENCH - 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, 2024)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical |
CAS Number |
State |
QS |
QC |
SL |
C3 |
TF |
TP |
RC |
TK |
RF |
Methacrylic acid |
79-41-4 |
Liquid |
|
|
|
81 |
>480 |
>480 |
>480 |
>480 |
>480 |
Methyl propenoic acid, 2- |
79-41-4 |
Liquid |
|
|
|
81 |
>480 |
>480 |
>480 |
>480 |
>480 |
Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be
used around heat, flames, sparks or in potentially flammable or
explosive environments. Only...
(DuPont, 2024)
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. Corrosive chemicals will destroy the membranes of the mouth, throat, and esophagus and, in addition, have a high risk of being aspirated into the victim's lungs during vomiting which increases the medical problems. 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. IMMEDIATELY transport the victim to a hospital. 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. Transport the victim IMMEDIATELY to a hospital. (NTP, 1992)
Physical Properties
Flash Point:
170°F
(NTP, 1992)
Lower Explosive Limit (LEL):
2.4 %
(USCG, 1999)
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature:
752°F
(USCG, 1999)
Melting Point:
61°F
(NTP, 1992)
Vapor Pressure:
0.65 mmHg
at 68°F
; 1 mmHg at 77°F
(NTP, 1992)
Vapor Density (Relative to Air):
2.97
(NTP, 1992)
- Heavier than air; will sink
Specific Gravity:
1.015
at 68°F
(USCG, 1999)
- Denser than water; will sink
Boiling Point:
325°F
at 760 mmHg
(NTP, 1992)
Molecular Weight:
86.09
(NTP, 1992)
Water Solubility:
greater than or equal to 100 mg/mL
at 63°F
(NTP, 1992)
Ionization Energy/Potential: data unavailable
IDLH: data unavailable
AEGLs (Acute Exposure Guideline Levels)
Interim AEGLs for Methacrylic acid (79-41-4)
Exposure Period |
AEGL-1 |
AEGL-2 |
AEGL-3 |
10 minutes |
6.7 ppm |
76 ppm |
280 ppm |
30 minutes |
6.7 ppm |
76 ppm |
280 ppm |
60 minutes |
6.7 ppm |
61 ppm |
220 ppm |
4 hours |
6.7 ppm |
38 ppm |
140 ppm |
8 hours |
6.7 ppm |
25 ppm |
71 ppm |
(NAC/NRC, 2024)
ERPGs (Emergency Response Planning Guidelines)
No ERPG information available.
PACs (Protective Action Criteria)
Chemical |
PAC-1 |
PAC-2 |
PAC-3 |
|
Methacrylic acid (79-41-4)
|
6.7 ppm |
61 ppm |
220 ppm |
LEL = 16000 ppm |
(DOE, 2024)
Regulatory Information
EPA Consolidated List of Lists
No regulatory information available.
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
- ALPHA-METHACRYLIC ACID
- ALPHA-METHYLACRYLIC ACID
- GE 110
- METHACRYLIC ACID
- METHACRYLIC ACID (GLACIAL)
- METHACRYLIC ACID (STABILIZED)
- METHACRYLIC ACID, STABILIZED
- 2-METHYL PROPENIC ACID
- 2-METHYL-2-PROPENOIC ACID
- METHYLACRYLIC ACID
- 2-METHYLACRYLIC ACID
- 2-METHYLENEPROPIONIC ACID
- 2-METHYLPROPENOIC ACID
- PROPENIONIC ACID, 2-METHYLENE