Heptane Chemical Properties
- Melting point:
- −91 °C(lit.)
- Boiling point:
- 98 °C(lit.)
- 0.684 g/mL at 20 °C
- vapor density
- 3.5 (vs air)
- vapor pressure
- 40 mm Hg ( 20 °C)
- refractive index
- Flash point:
- 30 °F
- storage temp.
- acetone: miscible(lit.)
- >14 (Schwarzenbach et al., 1993)
- Specific Gravity
- 0.684 (20/4℃)
- Relative polarity
- Odor Threshold
- explosive limit
- Water Solubility
- practically insoluble
- λ: 200 nm Amax: ≤1.0
λ: 225 nm Amax: ≤0.10
λ: 250 nm Amax: ≤0.01
λ: 300-400 nm Amax: ≤0.005
- Henry's Law Constant
- 0.901, 1.195, and 1.905(atm?m3/mol) at 26.0, 35.8, and 45.0 °C, respectively (dynamic headspace, Hansen et al., 1995)
- Exposure limits
- NIOSH REL: TWA 85 ppm (350 mg/m3), 15-min ceiling 440 ppm (1,800 mg/m3), IDLH 750 ppm; OSHA PEL: TWA 500 ppm (2,000 mg/m3); ACGIH TLV: TWA 400 ppm, STEL 500 ppm (adopted).
- Stable. Incompatible with oxidizing agents, chlorine, phosphorus. Highly flammable. Readily forms explosive mixtures with air.
- CAS DataBase Reference
- 142-82-5(CAS DataBase Reference)
- NIST Chemistry Reference
- EPA Substance Registry System
- Heptane (142-82-5)
- Hazard Codes
- Risk Statements
- Safety Statements
- UN 1206 3/PG 2
- WGK Germany
- Autoignition Temperature
- 433 °F
- HS Code
- Hazardous Substances Data
- 142-82-5(Hazardous Substances Data)
- LC (2 hr in air) in mice: 75 mg/l (Lazarew)
Heptane Usage And Synthesis
n-Heptane is a flammable liquid, present in crude oil and widely used in the auto- mobile industry. For example, as a solvent, as a gasoline knock testing standard, as automotive starter fl uid, and paraffi nic naphtha. n-Heptane causes adverse health effects in occupational workers, such as CNS depression, skin irritation, and pain. Other compounds such as n-octane (CH 3 (CH 2 ) 6 CH 3 ), n-nonane (CH 3 (CH 2 ) 7 CH 3 ), and n-decane (CH 3 (CH 2 ) 8 CH 3 ) have different industrial applications. Occupational workers exposed to these compounds also show adverse health effects. In principle, manage- ment of these aliphatic compounds requires proper handling and disposal to avoid health problems and to maintain chemical safety standards for safety to workers and the living environment.
n-Heptane is a clear liquid which is highly flammable and volatile with a mild, gasoline-like odor. The odor threshold is 40 547 ppm; also reported @ 230 ppm.
Clear, colorless, very flammable liquid with a faint, pleasant odor resembling hexane or octane. Based on a triangle bag odor method, an odor threshold concentration of 670 ppbv was reported by Nagata and Takeuchi (1990).
Suitable for HPLC, spectrophotometry, environmental testing
As standard in testing knock of gasoline engines.
heptane is a solvent and viscosity-decreasing agent.
A colorless liquid alkane obtained from petroleum refining. It is used as a solvent.
heptane: A liquid straight-chainalkane obtained from petroleum,C7H16; r.d. 0.684; m.p. -90.6°C; b.p.98.4°C. In standardizing octanenumbers, heptane is given a valuezero.
Heptane is produced in refining processes. Highly purified heptane is produced by adsorption of commercial heptane on molecular sieves.
Clear colorless liquids with a petroleum-like odor. Flash point 25°F. Less dense than water and insoluble in water. Vapors heavier than air.
Air & Water Reactions
Highly flammable. Insoluble in water.
HEPTANE is incompatible with the following: Strong oxidizers .
Toxic by inhalation. Flammable, dangerous fire risk.
VAPOR: Not irritating to eyes, nose or throat. If inhaled, will cause coughing or difficult breathing. LIQUID: Irritating to skin and eyes. If swallowed, will cause nausea or vomiting.
FLAMMABLE. Flashback along vapor trail may occur. Vapor may explode if ignited in an enclosed area.
Reactivity with Water No reaction; Reactivity with Common Materials: No reactions; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
n-Heptane is used in graphics, textiles, adhesives, and coatings; as an industrial solvent and in the petroleum refining process; as a standard in testing knock of gasoline engines.
Schauer et al. (1999) reported heptane in a diesel-powered medium-duty truck exhaust at
an emission rate of 470 g/km.
Identified as one of 140 volatile constituents in used soybean oils collected from a processing plant that fried various beef, chicken, and veal products (Takeoka et al., 1996).
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 heptane was 28.9 mg/kg of pine burned. Emission rates of heptane were not measured during the combustion of oak and eucalyptus.
California Phase II reformulated gasoline contained heptane at a concentration of 9,700 mg/kg.
Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 1.82 and 268 mg/km, respectively (Schauer et al., 2002).
Biological. Heptane may biodegrade in two ways. The first is the formation of heptyl
hydroperoxide, which decomposes to 1-heptanol followed by oxidation to heptanoic acid. The
other pathway involves dehydrogenation to 1-heptene, which may react with water forming 1-
heptanol (Dugan, 1972). Microorganisms can oxidize alkanes under aerobic conditions (Singer
and Finnerty, 1984). The most common degradative pathway involves the oxidation of the
terminal methyl group forming the corresponding alcohol (1-heptanol). The alcohol may undergo
a series of dehydrogenation steps forming heptanal followed by oxidation forming heptanoic acid.
The acid may then be metabolized by β-oxidation to form the mineralization products, carbon
dioxide and water (Singer and Finnerty, 1984). Hou (1982) reported hexanoic acid as a
degradation product by the microorganism Pseudomonas aeruginosa.
Photolytic. The following rate constants were reported for the reaction of hexane and OH radicals in the atmosphere: 7.15 x 10-12 cm3/molecule?sec (Atkinson, 1990). Photooxidation reaction rate constants of 7.19 x 10-12 and 1.36 x 10-16 cm3/molecule?sec were reported for the reaction of heptane with OH and NO3, respectively (Sablji? and Güsten, 1990). Based on a photooxidation rate constant 7.15 x 10-12 cm3/molecule?sec for heptane and OH radicals, the estimated atmospheric lifetime is 19 h in summer sunlight (Altshuller, 1991).
Chemical/Physical. Complete combustion in air yields carbon dioxide and water vapor. Heptane will not hydrolyze because it has no hydrolyzable functional group.
UN1206 Heptanes, Hazard Class: 3; Labels: 3-Flammable liquid.
May form explosive mixture with air. Strong oxidizers may cause fire and explosions. Attacks some plastics, rubber and coatings. May accumulate static electric charges that can ignite its vapors.
Dissolve or mix the material with a combustible solvent and burn in a chemical incinera tor equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.
Heptane Preparation Products And Raw materials
- Ethyl 2-bromoheptanoate
- 2-Ethylhexyl bromide
- Sodium 1-heptanesulfonate