Substance profile
Phthalic Anhydride
Phthalic Anhydride is white, lustrous needles with a mild odor.
01 · Identification
What Phthalic Anhydride is
Phthalic Anhydride is white, lustrous needles with a mild odor. Its molecular formula is C8H4O3 and its molecular weight is 148.11 g/mol. It boils at 285 °C, melts at 131 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
| H335 | May cause respiratory irritation. |
| H315 | Causes skin irritation. |
| H318 | Causes serious eye damage. |
| H334 | May cause allergy or asthma symptoms or breathing difficulties if inhaled. |
| H317 | May cause an allergic skin reaction. |
Precautionary statements: P261, P264, P270, P272, P280, P301, P302, P305, P310, P312, P313, P330, P332, P333, P338, P352
This page lists only the codes assigned to Phthalic Anhydride. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
03 · Physical and chemical properties
Phthalic Anhydride properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 285.3 °C (545.5 °F) | HSDB | |
| 295 °C (563 °F) | NIOSH | ||
| Melting point | 131.4 °C (268.5 °F) | HSDB | |
| 130.56 °C (267 °F) | NIOSH | ||
| 130.78 °C (267.4 °F) | CAMEO | ||
| Density | 1.2 g/cm³ | molten | HSDB |
| 1.53 g/cm³ | Flake | NIOSH | |
| 1.53 g/cm³ | ICSC | ||
| Solubility | In water, 6,000 mg/L at 25 °C | at 25 °C | HSDB |
| In water, 6,200 mg/L at 26 °C; 5,964 mg/L at room temperature | at 26 °C | HSDB | |
| Decomposes (NTP, 1992) | decomposes | CAMEO | |
| Vapor pressure | 0.0015 mmHg | NIOSH | |
| 0.0002 mmHg | at 20 °C | CAMEO | |
| 0.000517 mmHg | at 25 °C | HSDB | |
| Flash point | 151.67 °C (305 °F) | HSDB | |
| Autoignition temperature | 570 °C (1058 °F) | HSDB | |
| Lower explosive limit (LEL) | 1.7 % by volume | HSDB | |
| Upper explosive limit (UEL) | 10.5 % by volume | HSDB | |
| 10.4 % by volume | CAMEO | ||
| Vapor density | 6.6 (air = 1) | HSDB | |
| 5.1 (air = 1) | CAMEO | ||
| Odor threshold | Air: 0.053 ul/l; odor safety class C; C= Less than 50% of distracted persons perceive warning of TLV. | HSDB | |
| 0.32-0.72 mg/cu m | HSDB | ||
| Odor Threshold Low: 0.05 [mg/m3] | Haz-Map |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Phthalic Anhydride
Storage conditions
Chemical stability: Stable under recommended storage conditions.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Strong oxidizers, water [Note: Converted to phthalic acid in hot water].
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
PHTHALIC ANHYDRIDE reacts exothermically with water. The reactions are sometimes slow, but can become violent when local heating accelerates their rate. Acids accelerate the reaction with water. Incompatible with acids, strong oxidizing agents, alcohols, amines, and bases. Undergoes exothmeric nitration with fuming nitric acid-sulfuric acid and may give mixtures of the potentially explosive phthaloyl nitrates or nitrites or their nitro derivatives [Chem. & Ind. 20:790. 1972]. Phthalic anhydride reacts violently with CuO at elevated temperatures [Park, Chang-Man, Richard J. Sheehan. "Phthalic Acids and Other Benzenepolycarboxylic Acids" Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. 2005]. Mixtures of phthalic anhydride and anhydrous CO2 explode violently if heated [Leaflet No. 5, Inst. of Chem., London, 1940].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Phthalic Anhydride in the storage compatibility matrix →
Safety Data Sheet
Getting an SDS for Phthalic Anhydride
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Phthalic Anhydride issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
Nearby
Substances next to Phthalic Anhydride
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