ABSTRACT
CASRN: 108-24-7; DOT: 1715; DOT label: Corrosive; molecular formula: C4H6O3; FW: 102.09; RTECS: AK1925000; Merck Index: 12, 53 Physical state, color, and odor: Colorless, very mobile liquid with a very strong, acetic acid-like odor. Experimentally determined detection and recognition odor threshold concentrations were <600 µg/m3 (<140 ppbv) and 1.5 mg/m3 (360 ppbv), respectively (Hellman and Small, 1974). Melting point (°C): -73.1 (Acros Organics, 2002) Boiling point (°C): 139.55 (Weast, 1986) Density (g/cm3): 1.080 at 15 °C (Windholz et al., 1983) 1.0820 at 20 °C (Weast, 1986) 1.07502 at 25 °C (Aboy et al., 2002) Flash point (°C): 54.4 (Windholz et al., 1983) Lower explosive limit (%): 2.7 (NIOSH, 1994) Upper explosive limit (%): 10.3 (NIOSH, 1994) Ionization potential (eV): ≈ 10.00 (Lias et al., 1998) Soil organic carbon/water partition coefficient, log Koc: Not applicable for anhydrides because they are readily hydrolyzed by water forming the corresponding acid. Nevertheless, experimental methods for estimation of this parameter for hydrolysis products of anhydrides are lacking in the documented literature. Given that the hydrolysis product (acetic acid) is completely miscible with water in all proportions suggests its adsorption to soil will be nominal (Lyman et al., 1982). Octanol/water partition coefficient, log Kow: -0.17 at pH 3.5 and 25 °C for acetic acid (shake flask-absorption spectrometry, Takacs-Novak and
Szasz, 1999) Solubility in organics: Miscible with acetic acid, alcohol, and ether (Hawley, 1981)
Although NIOSH (1994) reports a solubility of 12 wt % at 20 °C, this value is not relevant because acetic anhydride reacts with water forming acetic acid. Acetic acid is completely miscible with water. Vapor density: 4.17 g/L at 25 °C, 3.52 (air = 1) Vapor pressure (mmHg): 3.5 at 20 °C, 5 at 25 °C, 7 at 30 °C (quoted, Verschueren, 1983) 44.6 at 62.84 °C (dynamic boiling point method, McDonald et al., 1959) Environmental fate: Chemical/Physical. Slowly dissolves in water forming acetic acid. In ethanol, ethyl acetate is formed (Windholz et al., 1983). Exposure limits: NIOSH REL: ceiling 5 ppm (20 mg/m3), IDLH 200 ppm; OSHA PEL: 5 ppm; ACGIH TLV: ceiling 5 ppm. Symptoms of exposure: Severe eye and skin irritant (NIOSH, 1997). An irritation concentration of 20.00 mg/m3 in air was reported by Ruth (1986). Toxicity: Acute oral LD50 for rats 1,780 mg/kg (quoted, RTECS, 1985). LC50 (inhalation) 1,000 ppm/4-h (quoted, RTECS, 1985). Uses: Preparation of acetyl compounds and cellulose acetates; detection of rosin; dehydrating and acetylating agent in the production of pharmaceuticals, dyes, explosives, perfumes, and pesticides; organic synthesis.
