NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Methacrylic acid

CAS
79-41-4

CH2=C(CH3)COOH

RTECS
OZ2975000
Synonyms & Trade Names

Methacrylic acid (glacial), Methacrylic acid (inhibited), alpha-Methacrylic acid, 2-Methylacrylic acid, 2-Methylpropenoic acid
DOT ID & Guide
2531 / 153P (inhibited)

Exposure
Limits

NIOSH REL: TWA 20 ppm (70 mg/m3) [skin]
OSHA PEL: none
IDLH
N.D. See: IDLH INDEX
Conversion
1 ppm = 3.52 mg/m3
Physical Description
Colorless liquid or solid (below 61°F) with an acrid, repulsive odor.
MW: 86.1
BP: 325°F
FRZ: 61°F
Sol(77°F): 9%
VP: 0.7 mmHg
IP: ?

Sp.Gr: 1.02 (Liquid)
Fl.P(oc): 171°F
UEL: ?
LEL: ?

Class IIIA Combustible Liquid: Fl.P. at or above 140F and below 200F.
Incompatibilities & Reactivities

Oxidizers, elevated temperatures, hydrochloric acid [Note: Typically contains 100 ppm of the monomethyl ether of hydroquinone to prevent polymerization.]
Measurement Methods
OSHA PV2005
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated
Remove: When wet or contaminated
Change: Daily
Provide: Eyewash, Quick drench
First Aid
(See procedures)
Eye: Irrigate immediately
Skin: Water flush immediately
Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations
Not available.
Important additional information about respirator selection
Exposure Routes
inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms
Irritation eyes, skin, mucous membrane; eye, skin burns
Target Organs
Eyes, skin, respiratory system
See also: INTRODUCTION   See ICSC CARD: 0917