# NIOSH Pocket Guide to Chemical Hazards
Dimethylphthalate | CAS 131-11-3
C6H4(COOCH3)2 | RTECS TI1575000
Synonyms & Trade Names Dimethyl ester of 1,2-benzenedicarboxylic acid; DMP | DOT ID & Guide 9188 171 (hazardous substance, n.o.s.)
Exposure Limits | NIOSH REL: TWA 5 mg/m3
OSHA PEL: TWA 5 mg/m3
IDLH 2000 mg/m3 | Conversion
Physical Description Colorless, oily liquid with a slight, aromatic odor. [Note: A solid below 42°F.]
MW: 194.2 | BP: 543°F | FRZ: 42°F | Sol: 0.4%
VP: 0.01 mmHg | IP: 9.64 eV |  | Sp.Gr: 1.19
Fl.P: 295°F | UEL: ? | LEL(358°F): 0.9% |
Class IIIB Combustible Liquid; however, ignition is difficult.
Incompatibilities & Reactivities Nitrates; strong oxidizers, alkalis & acids
Measurement Methods OSHA 104
Personal Protection & Sanitation Skin: No recommendation Eyes: Prevent eye contact Wash skin: No recommendation Remove: No recommendation Change: No recommendation | First Aid (See procedures) Eye: Irrigate promptly Skin: Wash regularly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 50 mg/m3: (APF = 10) Any dust and mist respirator with a full facepiece Up to 125 mg/m3: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode£/(APF = 25) Any powered, air-purifying respirator with a dust and mist filter£ Up to 250 mg/m3: (APF = 50) Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 2000 mg/m3: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode 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 with a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, upper respiratory system; stomach pain
Target Organs Eyes, respiratory system, gastrointestinal tract
See also: INTRODUCTION