Hazard
Flammable, dangerous fire risk, explosivelimits in air 1–6%.
Chemical Properties
clear colorless liquid
Physical properties
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).
Source
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).
Environmental Fate
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.
Purification Methods
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.]
Toxics Screening Level
The initial threshold screening level (ITSL) for 2-methylhexane is 3,500 μg/m3 based on an 8-hr averaging time.
