Heptane

log Kow = 4.66

4.66

4.66

4.48

0.6838 at 68 °F (USCG, 1999) - Less dense than water; will float

0.6795 g/cu cm at 25 °C

% in saturated air: 6.3 at 25 °C, 760 mm Hg; density of air saturated with vapor: 1.18 at 25 °C, 760 mm Hg

Density (at 20 °C): 0.68 g/ml

0.68

0.684 @25 °C

0.0003 % (NIOSH, 2024)

In water, 3.40 mg/L at 25 °C

Soluble in carbon tetrachloride; very soluble in ethanol; miscible with ethyl ether, acetone, benzene, chloroform, and petroleum ether

0.0034 mg/mL at 25 °C

Solubility in water, mg/l at 25 °C: 2.2 (very poor)

0.0003%

Danger

H225: Highly Flammable liquid and vapor [Danger Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P271, P273, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P319, P321, P331, P332+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Danger

H225 (100%): Highly Flammable liquid and vapor [Danger Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P271, P273, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P319, P321, P331, P332+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Chemical: Heptane

Regulation (EC) No 178/2002 (amended)

Heptane is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Heptane are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 09-12-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/14228

Heptane: HSNO Approval: HSR001164 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

FLAMMABLE. Flashback along vapor trail may occur. Vapor may explode if ignited in an enclosed area. (USCG, 1999)

· HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.

Highly flammable. Vapour/air mixtures are explosive.

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. (USCG, 1999)

CAUTION: Petroleum crude oil (UN1267) may contain TOXIC hydrogen sulphide gas.

1206 128

1206 128

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date: 1/26/94; Reporting date: 3/28/94.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Heptane is included on this list. Effective date: 1/26/94; Sunset date: 6/30/98.

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 500 ppm (2000 mg/cu m).

Vacated 1989 OSHA PEL TWA 400 ppm (1600 mg/cu m); STEL 500 ppm (2000 mg/cu m) is still enforced in some states.

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

Use alcohol-resistant foam, dry powder, carbon dioxide, water spray. In case of fire: keep drums, etc., cool by spraying with water.

Fresh air, rest. Refer for medical attention.

Rinse and then wash skin with water and soap. Refer for medical attention if skin irritation occurs.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give nothing to drink. Do NOT induce vomiting. Refer immediately for medical attention.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

Excerpt from NIOSH Pocket Guide for n-Heptane:

General First Aid:

(General first aid procedures)

· Wear positive pressure self-contained breathing apparatus (SCBA).

500.0 [ppm]

For small (incipient) fires, use media such as "alcohol" foam, dry chemical, or carbon dioxide. For large fires, apply water from as far as possible. Use very larg quantities (flooding) of water applied as a mist or spray; solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water.

In case of fire: Evacuate area. Fight fire remotely due to the risk of explosion. Use water spray to cool unopened containers.

Collect leaking liquid in sealable containers... Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Do NOT wash away into sewer. Personal protection: filter respirator for organic gases and vapors adapted to the airborne concentration of the substance.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material.

The following wastewater treatment technologies have been investigated for heptane: Biological treatment.

n-Heptane was detected in 7 of 12 samples of mothers breast milk from the cities of Bayonne, NJ; Jersey City, NJ; Bridgeville, PA; and Baton Rouge, LA(1). n-Heptane has also been detected in mother's milk collected from Pittsburgh, PA(2). The concentrations of n-heptane in the samples from these studies were not reported(SRC).

LC50; Species: Chaetogammarus marinus /amphipod/; Concentration: 0.2 mg/L for 96 hr /Conditions of bioassay not specified in source examined/

LC50; Species: Mysidopsis bahia (Opossum shrimp); Concentration: 0.1 mg/L for 96 hr /Conditions of bioassay not specified in source examined/

LC50; Species: Carassius auratus (Goldfish); Concentration: 4 mg/L for 24 hr /Conditions of bioassay not specified in source examined/

LC50; Species: Leuciscus idus melanotus (Golden orfe); Concentration: 2940 mg/L for 48 hr /Conditions of bioassay not specified in source examined/ /formulated product/

For more Ecotoxicity Values (Complete) data for n-Heptane (9 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 240(SRC), determined from a structure estimation method(2), indicates that n-heptane is expected to have moderate mobility in soil(SRC). Volatilization of n-heptane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.8 atm-cu m/mole(SRC), based upon its vapor pressure, 46 mm Hg(3), and water solubility, 3.4 mg/L(4). n-Heptane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 46 mm Hg at 25 °C(3). A 101% of theoretical BOD using activated sludge in the Japanese MITI test(5) suggests that biodegradation is an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 240(SRC), determined from a structure estimation method(2), indicates that n-heptane is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 1.8 atm-cu m/mole(SRC), derived from its vapor pressure, 46 mm Hg(4), and water solubility, 3.4 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2.9 hours and 4.0 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 550(SRC), from its log Kow of 4.66(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is high(SRC). A 101% of theoretical BOD using activated sludge in the Japanese MITI test(9) suggests that biodegradation is an important environmental fate process in water.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), n-heptane, which has a vapor pressure of 46 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase n-heptane is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 2.2 days(SRC), calculated from its rate constant of 7.15X10-12 cu cm/molecule-sec at 25 °C(3). n-Heptane does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

The concentration of n-heptane measured in the volatile components of duck meat, duck fat, cantonese style roasted duck, and cantonese style roasted duck gravy were 1.34, 3.47, 17.29, and 6.51 ppb on a wet basis, respectively(1). n-Heptane was identified (unspecified concentrations) in both the noncondensable volatile fraction and in the condensable lipid fraction headspace of raw beef(2). n-Heptane has been detected in dry-cured hams at different stages of the manufacturing process; however, the concentrations were not specified(3). n-Heptane was identified as a volatile component of fried bacon(4), roasted filberts(5) and nectarines(6). n-Heptane has been detected (unspecified concentrations) in boiled Chinese Chestnuts(7). n-Heptane has been identified in headspace samples of heated peanut oil(8). n-Heptane has been detected in the headspace of floured chickpea seed(9).

Neurotoxin - Acute solvent syndrome

Compound with “poor evidence” of ototoxicity (it is a questionably ototoxic substance).

The substance can be absorbed into the body by inhalation of its vapour and by ingestion.

inhalation, ingestion, skin and/or eye contact

Oral (T29) ; inhalation (T29) ; dermal (T29)

n-Heptane was detected in 7 of 12 samples of mothers breast milk from the cities of Bayonne, NJ; Jersey City, NJ; Bridgeville, PA; and Baton Rouge, LA(1). n-Heptane has also been detected in mother's milk collected from Pittsburgh, PA(2). The concentrations of n-heptane in the samples from these studies were not reported.

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date: 1/26/94; Reporting date: 3/28/94.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Heptane is included on this list. Effective date: 1/26/94; Sunset date: 6/30/98.

In the present molecular dynamics simulations /investigators/ study the chemical warfare agent sulfur mustard (bis(2-chloroethyl) sulfide) and the alkane heptane inserted into a dipalmitoylphosphatidylcholine (DPPC) bilayer, a generic model for a biological membrane. /They/ investigate the diffusion, the orientation, the preferred positioning, and the end-to-end distance of the solutes within the membrane as well as the corresponding coupling times. /Investigators/ compare results of equilibrium simulations and simulation at different external forces, which drag the solutes through the membrane. These properties lead to a general comparison of the rotational and translational behaviors of the two solutes during the penetration of the membrane... For heptane the hindrance to penetrate into the membrane is significantly higher than for sulfur mustard. In contrast to heptane molecules, which spend the most of the time penetrating the tail groups, sulfur mustard needs more time to escape the tail group-head group interface of the membrane.

Heptane is metabolized to its parent alcohols (mainly 2-heptanol and 3 heptanol, and to a minor extent 1-heptanol and 4- heptanol). The heptanol metabolites are conjugated by glucuronates or sulfates, and subsequently excreted in urine. Heptane is further metabolized at relatively high rates by hydroxylation before being converted to the corresponding keto forms. Diketone metabolic products, believed to be responsible for neurotoxicity, are produced to a lower extent compared to hexane in agreement with the finding that heptane is less neurotoxic. In vitro studies have shown that at least three cytochrome P450 isozymes are involved in the liver metabolism of heptane.

...Female Wistar rats were exposed to 2000 ppm n-heptane inhalation for 12 weeks. Metabolites in urine were identified by gas chromatography-mass spectrometry. Urinary metabolites were quantified following 6-hr n-heptane exposures. n-Heptane metabolites were 1-, 2-, 3-, and 4-heptanols, 2- and 3-heptanones, 2,5- and 2,6-heptanediols, 5-hydroxy-2-heptanone, 6-hydroxy-2-heptanone, 6-hydroxy-3-heptanone, 2,5- and 2,6-heptanediones, and gamma-valerolactone. The amount of urinary metabolites increased greatly after the second exposure day, achieving a steady-state concentration on subsequent exposure days over the 12 weeks of the exposure regimen. These results showed that n-heptane was metabolized mainly by hydroxylation at omega- 1 carbon atom and to a lesser extent at the omega- 2 carbon atom. 2-Heptanol, 6-hydroxy-2-heptanone, and 3-heptanol were the major metabolites and were excreted as sulfates and glucuronides. 2,5-Heptanedione, which is a neurotoxic agent, was the metabolite found in least amounts (2.4 +/- 2 ug/rat) in the urine. No clinical evidence of neurotoxicity was observed after n-heptane exposure.

Cytochrome P450 is a unique enzyme that produces n-heptane metabolites of different oxidation states. Metabolism of n-heptane was investigated with rat liver microsomes and a reconstituted rat liver system. Ethanol, n-propanol, and n-butanol molecules interacted with the n-heptane molecule and resulted in cytochrome P450 spectral changes as well as alterations in the n-heptane metabolic profile. The observed modifications in the biotransformation of n-heptane indicated that there are three distinct pathways for oxidation of n-heptane to heptanols, heptanones, and one-side oxygen-oriented heptanediones.

Volatile hydrocarbons are absorbed mainly through the lungs, and may also enter the body after ingestion via aspiration. (A600)

Studies in rats suggest that heptane enters the organism mainly by inhalation, and to a minor degree by dermal absorption.

...Percutaneous absorption and dermal toxicity of three components of JP-8 (i.e., xylene, heptane, and hexadecane) /were determined/ in vivo in weanling pigs. In vivo percutaneous absorption results suggest a greater absorption of hexadecane (0.43%) than xylene (0.17%) or heptane (0.14%) of the applied dose after 30 min exposure. Transepidermal water loss (TEWL) provides a robust method for assessing damage to the stratum corneum. Heptane showed greater increase in TEWL than the other two chemicals. No significant (p<0.05) increase in temperature was observed at the chemically treated site than the control site. Heptane showed greater TEWL values and erythema score than other two chemicals (xylene and hexadecane).

Standard for octane-rating determinations (pure normal heptane has zero octane number) anesthetic, solvent, organic synthesis, preparation of laboratory reagents. [HSDB]

Standard for octane-rating determinations (pure normal heptane has zero octane number) anesthetic, solvent, organic synthesis, preparation of laboratory reagents.

As standard in testing knock of gasoline engines.

Research chemical

Heptanes may be found in gasoline and are widely used as solvents. They are also sold as fuel for outdoor stoves. (L1289)

2023: 400,000,000 - <550,000,000 lb

(1986) >100 million - 500 million pounds

(1990) >100 million - 500 million pounds

(1994) >100 million - 500 million pounds

(1998) >100 million - 500 million pounds

For more U.S. Production (Complete) data for n-Heptane (10 total), please visit the HSDB record page.

Fractional distillation of petroleum, purified by rectification.

n-Alkanes having more than six carbon atoms are not isolated individually but as mixtures of several homologues. Suitable sources are the appropriate petroleum distillate fractions, from which the n-paraffins can be isolated in high isomeric purity (greater than or equal to 95% linearity) by selective separation (eg, molecular sieve separation or urea extractive crystallization). /Higher n-Alkanes/

Hydrogenation of 1-heptene

Food Additives -> EXTRACTION_SOLVENT -> JECFA Functional Classes

Cosmetics -> Solvent; Hair dyeing

Petrochemical Manufacturing

Heptane: ACTIVE