- Phthalic acid anhydride
- 1,2-Benzenedicarboxylic acid anhydride
- 1,3 Dixophthalan
Thin white flakes with a characteristic choking odor.
Manufacture phthaleins, phthalates, benzoic acid, synthetic indigo, artificial resins (glyptal).
Registry Numbers and Inventories.
EC Index Number
Harmful; Irritant; Sensitising
R 22 37/38 41 42/43
S 23 24/25 26 37/39 46
Tumorigen; Mutagen; Reproductive Effector; Primary Irritant
Swiss Giftliste 1
Japan ENCS (MITI)
Melting point, °C
Boiling point, °C
Vapor pressure, mmHg
0.0002 (20 C)
Vapor density (air=1)
0.26 ppm at 20 C (calculated)
Odor Threshold Odor threshold 0.32-0.72 mg/m3
1.545 g/cm3 (20 C)
Solubility in water
6.2 g/L (20 C)
1.125 cp (155 C)
35.5 g/s2 (115 C)
Partition coefficient, pKow
Heat of fusion
Heat of vaporization
Heat of combustion
Hazards and Protection.
Keep container closed when not in use. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from water. Corrosives area.
Wash thoroughly after handling. Use only in a well ventilated area. Use with adequate ventilation. Ground and bond containers when transferring material. Do not breathe dust, vapor, mist, or gas. Do not get in eyes, on skin, or on clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Do not ingest or inhale. Do not allow contact with water. Discard contaminated shoes. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
Wear impervious protective clothing, including boots, gloves, lab coat, apron or coveralls, as appropriate, to prevent skin contact. Rubber and neoprene are recommended materials for personal protective equipment. Use chemical safety goggles and/or full face shield where dusting or splashing of solutions is possible. Maintain eye wash fountain and quick-drench facilities in work area.
A full-face piece respirator with an organic vapor cartridge and particulate filter (NIOSH type N100 filter) may be worn up to 50 times the exposure limit, or the maximum use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest. If oil particles (e.g. lubricants, cutting fluids, glycerine, etc.) are present, use a NIOSH type R or P particulate filter. For emergencies or instances where the exposure levels are not known, use a full-face piece positive-pressure, air-supplied respirator.
Clean up spills immediately, using the appropriate protective equipment. Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Avoid generating dusty conditions. Remove all sources of ignition. Use a spark-proof tool. Provide ventilation. Do not get water inside containers.
Stable under ordinary conditions of use and storage. Heat will contribute to instability. When molten it should be covered with inert gas.
Strong oxidizers. nitric acid, sodium nitrite, copper oxide.
Carbon dioxide and carbon monoxide may form when heated to decomposition. Slowly reacts with water to form phthalic acid.
Upper exp. limit, %
Lower exp. limit, %
Wear full protective clothing and NIOSH-approved self-contained breathing apparatus with full facepiece operated in the pressure demand or other positive pressure mode. Extinguish fire with water spray, dry chemical, alcohol foam, or carbon dioxide. Water or foam may cause frothing.
May burn but does not ignite readily.
Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. When heated, vapors may form explosive mixtures with air: indoors, outdoors, and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.
Fire will produce irritating, corrosive and/or toxic gases.
NIOSH REL: TWA 6 mg/m3 (1 ppm) OSHA PEL: TWA 12 mg/m3 (2 ppm) IDLH 60 mg/m3
Contact with water causes formation of phthalic acid, which is responsible for the corrosive effects. Corrosive effects may be delayed several hours. Chronic exposure by inhalation or skin contact can cause allergic sensitization. Causes liver and kidney effects in laboratory animals.
Corrosive. Swallowing can cause severe burns of the mouth, throat, and stomach. Can cause sore throat, vomiting, diarrhea.
Inhalation of vapor, fume or dust is a primary irritant. Coughing, choking, as well as headache and dizziness can occur. May cause allergic respiratory reaction.
Corrosive. Symptoms of redness, pain, and severe burn can occur. May cause allergic skin reactions.
Conjunctival edema and corneal destruction can occur. Symptoms include pain, tearing, and photophobia.
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. Destroy contaminated shoes.
Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed. Gently lift eyelids and flush continuously with water. Extensive irrigation is required (at least 30 minutes).