NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Phthalic anhydride

CAS
85-44-9

C6H4(CO)2O

RTECS
TI3150000
Synonyms & Trade Names

1,2-Benzenedicarboxylic anhydride; PAN; Phthalic acid anhydride
DOT ID & Guide
2214 / 156

Exposure
Limits

NIOSH REL: TWA 6 mg/m3 (1 ppm)
OSHA PEL: TWA 12 mg/m3 (2 ppm)
IDLH
60 mg/m3 See: 85449
Conversion
1 ppm = 6.06 mg/m3
Physical Description
White solid (flake) or a clear, colorless, mobile liquid (molten) with a characteristic, acrid odor.
MW: 148.1
BP: 563°F
MLT: 267°F
Sol: 0.6%
VP: 0.0015 mmHg
IP: 10.00 eV

Sp.Gr: 1.53 (Flake) 1.20 (Molten)
Fl.P: 305°F
UEL: 10.5%
LEL: 1.7%

Combustible Solid
Incompatibilities & Reactivities

Strong oxidizers, water [Note: Converted to phthalic acid in hot water.]
Measurement Methods
NIOSH S179 (II-3); OSHA 90
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

First Aid
(See procedures)
Eye: Irrigate immediately
Skin: Soap wash promptly
Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations
NIOSH
Up to 30 mg/m3:
(APF = 5) Any quarter-mask respirator. Click here for information on selection of N, R, or P filters.*
Up to 60 mg/m3:
(APF = 10) Any particulate respirator equipped with an N95, R95, or P95 filter (including N95, R95, and P95 filtering facepieces) except quarter-mask respirators. The following filters may also be used: N99, R99, P99, N100, R100, P100. Click here for information on selection of N, R, or P filters.*
(APF = 10) Any air-purifying, full-facepiece respirator equipped with an N95, R95, or P95 filter. The following filters may also be used: N99, R99, P99, N100, R100, P100. Click here for information on selection of N, R, or P filters.
(APF = 25) Any powered air-purifying respirator with a high-efficiency particulate filter.*
(APF = 10) Any supplied-air respirator*
(APF = 50) Any self-contained breathing apparatus 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 with an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters./Any appropriate escape-type, self-contained breathing apparatus
Important additional information about respirator selection
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
Irritation eyes, skin, upper respiratory system; conjunctivitis; nasal ulcer bleeding; bronchitis, bronchial asthma; dermatitis; in animals: liver, kidney damage
Target Organs
Eyes, skin, respiratory system, liver, kidneys
See also: INTRODUCTION   See ICSC CARD: 0315   See MEDICAL TESTS: 0192