METHACRYLIC ACID

Chemical Identification
CAS # 79-41-4
Formula

C₄H₆O₂

Synonyms

methacrylic acid (glacial); methacrylic acid (inhibited); α-methacrylic acid; 2-methylacrylic acid; 2-methylpropenoic acid

Physical Properties
Physical description Colorless liquid or solid (below 61°F) with an acrid, repulsive odor.
Boiling point 325°F Molecular weight 86.09
Freezing point/melting point 61°F Vapor pressure 0.7 mmHg
Flash point 171°F (open-cup) Vapor density 2.97
Specific gravity 1.015 at 68°F Ionization potential
Lower explosive limit (LEL) Upper explosive limit (UEL) 2.4%
NFPA health rating 3 NFPA fire rating 2
NFPA reactivity rating 2 NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) M339
Sampling group
Sampler/Sampling media 2 Anasorb 708 tubes in series [SKC 226-30-08]
Sampling time*
 

240 min

Sampling volume (TWA)*
 

24 L

Sampling flow rate (TWA)*
 

0.1 L/min

Sampling volume (STEL/Peak/C)*
 

 

Sampling flow rate (STEL/Peak/C)*
 

 

Analytical method instruments HPLC
Method reference OSHA PV2005 (partially validated)
Notes
 

 

Special requirements
 

 

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Sampler/Sampling media
 

 

Bulk Method
Bulk Method
 

 

On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA
 

 

REL-TWA
 

20 ppm (70 mg/m³)

TLV-TWA
 

20 ppm [1992]

PEL-TWA
 

20 ppm (70 mg/m³)

PEL-STEL
 

 

REL-STEL
 

 

TLV-STEL
 

 

PEL-STEL
 

 

PEL-C
 

 

REL-C
 

 

TLV-C
 

 

PEL-C
 

 

Skin notation
 

NA

Skin notation
 

Y

Skin notation
 

N

Skin notation
 

Y

Notes:
 

Not established

Notes:
 

 

Notes:
 

 

Notes:
 

 

Health factors:  See NIH-NLM PubChem. IDLH
Carcinogenic classifications: Not listed Notes:
 

 

AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
 

 

Last Updated Date : 01/29/2021