Clear, colorless, flammable, watery liquid with an odor similar to pentane, 2-methylpentane, 3-
methylpentane, hexane, and 3-hexane. An odor threshold concentration of 420 ppbv was reported
by Nagata and Takeuchi (1990).
2-Methylhexane is mainly used as a model iso-alkane in studies relating to iso-alkane oxidation, vapor-liquid phase equilibria of heptane isomers and catalytic cracking.
Flammable, dangerous fire risk, explosivelimits in air 1–6%.
Schauer et al. (1999) reported 2-methylhexane in a diesel-powered medium-duty truck
exhaust at an emission rate of 570 μg/km.
Schauer et al. (2001) measured organic compound emission rates for volatile organic
compounds, gas-phase semi-volatile organic compounds, and particle-phase organic compounds
from the residential (fireplace) combustion of pine, oak, and eucalyptus. The gas-phase emission
rate of 2-methylhexane was 2.6 mg/kg of pine burned. Emission rates of 2-methylhexane were not
measured during the combustion of oak and eucalyptus.
California Phase II reformulated gasoline contained 2-methylhexane at a concentration of 15.3
g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without
catalytic converters were 2.88 and 372 mg/km, respectively (Schauer et al., 2002).
Biological. Riser-Roberts (1992) reported 2- and 5-methylhexanoic acids as metabolites by the
microorganism Pseudomonas aeruginosa.
Photolytic. Based on a reported photooxidation reaction rate constant of 6.80 x 10-12
cm3/molecule?sec with OH radicals, the half-life of 2-methylhexane is 25 h (Altshuller, 1990).
Chemical/Physical. Complete combustion in air produces carbon dioxide and water vapor. 2-
Methylhexane will not hydrolyze because it does not contain a hydrolyzable functional group.
Purify it by azeotropic distillation with MeOH, then wash it with water (to remove the MeOH), dry it over type 4A molecular sieves and distil it. [Beilstein 1 IV 397.]
