# NIOSH Pocket Guide to Chemical Hazards
Methyl methacrylate | CAS 80-62-6
CH2=C(CH3)COOCH3 | RTECS OZ5075000
Synonyms & Trade Names Methacrylate monomer, Methyl ester of methacrylic acid, Methyl-2-methyl-2-propenoate | DOT ID & Guide 1247 129P (inhibited)
Exposure Limits | NIOSH REL: TWA 100 ppm (410 mg/m3)
OSHA PEL: TWA 100 ppm (410 mg/m3)
IDLH 1000 ppm | Conversion 1 ppm = 4.09 mg/m3
Physical Description Colorless liquid with an acrid, fruity odor.
MW: 100.1 | BP: 214°F | FRZ: -54°F | Sol: 1.5%
VP: 29 mmHg | IP: 9.70 eV |  | Sp.Gr: 0.94
Fl.P(oc): 50°F | UEL: 8.2% | LEL: 1.7% |
Class IB Flammable Liquid: Fl.P. below 73°F and BP at or above 100°F.
Incompatibilities & Reactivities Nitrates, oxidizers, peroxides, strong alkalis, moisture [Note: May polymerize if subjected to heat, oxidizers, or ultraviolet light. Usually contains an inhibitor such as hydroquinone.]
Measurement Methods NIOSH 2537; OSHA 94
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet (flammable) Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Skin: Water flush promptly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 1000 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode£/(APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)£/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat; dermatitis
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION