ABSTRACT
NH2 CASRN: 106-50-3; DOT: 1673; DOT label: Poison; molecular formula: C6H8N2; FW: 108.14; RTECS: SS8050000; Merck Index: 12, 7439 Physical state and color: White, red, or brown crystals. May darken on exposure to air. Melting point (°C): 140 (Weast, 1986) 145-147 (Windholz et al., 1983) Boiling point (°C): 267 (Weast, 1986) 271 (Du Pont, 1999h) Diffusivity in water (x 10-5 cm2/sec): 0.78 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant: At 25 °C: pK1 = 3.29, pK2 = 6.08 (Dean, 1973) Flash point (°C): 156.8 (NIOSH, 1997) 154 (Du Pont, 1999h) Entropy of fusion (cal/mol⋅K): 14.3 (Rai and Mandal, 1990) Heat of fusion (kcal/mol): 5.951 (Rai and Mandal, 1990) Ionization potential (eV): 6.87 (Lias, 1998) Bioconcentration factor, log BCF: 2.66 (activated sludge), 2.65 (algae) (hydrochloride, Freitag et al., 1985)
oc Unavailable because experimental methods for estimation of this parameter for aromatic amines are lacking in the documented literature Octanol/water partition coefficient, log Kow: Unavailable because experimental methods for estimation of this parameter for aromatic amines are lacking in the documented literature Solubility in organics: Soluble in alcohol ether (Weast, 1986) and slightly soluble in chloroform (Du Pont, 1999h) Solubility in water: 4.7 wt % at 20 °C (NIOSH, 1987) 3.69 wt % at 20 °C (Budavari et al., 1996) 38,000 mg/L at 24 °C, 6,690 g/L at 107 °C (quoted, Verschueren, 1983) 10.0 wt % at 40 °C (Du Pont, 1999h) Vapor pressure (mmHg): 0.00091 and 1.0797 at 39 and 100.0 °C, respectively (Du Pont, 1999h) Environmental fate: Biological. In activated sludge, 3.8% mineralized to carbon dioxide after 5 d (Freitag et al., 1985). In activated sludge inoculum, following a 20-d adaptation period, 80.0% COD removal was achieved (Pitter, 1976). Photolytic. A carbon dioxide yield of 53.7% was achieved when phenylenediamine (presumably an isomeric mixture) adsorbed on silica gel was irradiated with light (λ >290 nm) for 17 h (Freitag et al., 1985). Chemical/Physical. p-Phenylenediamine will not hydrolyze because it does not contain a hydrolyzable functional group (Kollig, 1993). Exposure limits (mg/m3): NIOSH REL: TWA 0.1, IDLH 25; OSHA PEL: TWA 0.1; ACGIH TLV: TWA 0.1 (adopted). Symptoms of exposure: May include vertigo, gastritis, jaundice, allergic asthma, dermatitis, cornea ulcer, eye burn (Patnaik, 1992) Toxicity: LC50 (48-h) for red killifish 186 mg/L (Yoshioka et al., 1986). Acute oral LD50 for wild birds 100 mg/kg, quail 100 mg/kg, rats 80 mg/kg (quoted, RTECS, 1985). Source: Bulk quantitities may contain m-and o-phenylenediamine and aniline as impurities. Uses: Manufacturing azo dyes, intermediates for antioxidants and accelerators for rubber; photochemical measurements; laboratory reagent; dyeing hair and fur.
