Cyclohexane Property

Melting point:

4-7 °C (lit.)

Boiling point:

80.7 °C (lit.)

Density 

0.779 g/mL at 25 °C (lit.)

vapor density 

2.9 (vs air)

vapor pressure 

168.8 mm Hg ( 37.7 °C)

refractive index 

n20/D 1.426(lit.)

Flash point:

-1 °F

storage temp. 

Store at +5°C to +30°C.

solubility 

ethanol: miscible(lit.)

form 

Liquid

color 

colorless

Relative polarity

0.006

Odor

resembling benzene; mild, sweet, resembling chloroform.

Odor Threshold

2.5ppm

explosive limit

1.2-8.3%(V)

Water Solubility 

PRACTICALLY INSOLUBLE

FreezingPoint 

6.554℃

λmax

λ: 210 nm Amax: ≤1.00
λ: 220 nm Amax: ≤0.50
λ: 230 nm Amax: ≤0.20
λ: 235 nm Amax: ≤0.10
λ: 240 nm Amax: ≤0.08
λ: 250 nm Amax: ≤0.03
λ: 255 nm Amax: ≤0.01

Merck 

14,2723

BRN 

1900225

Henry's Law Constant

1.03, 1.26, 1.40, 1.77, and 2.23 at 10, 15, 20, 25, and 30 °C, respectively (EPICS, Ashworth et al., 1988) 0.54, 0.69, 0.82, 1.43, and 1.79 at 2.0, 6.0, 10.0, 18.0, and 25.0 °C, respectively (Dewulf et al.,1999)

Exposure limits

TLV-TWA 300 ppm (～1050 mg/m³) (ACGIH, OSHA, and NIOSH); IDLH 10,000 ppm (NIOSH).

Dielectric constant

2.0（20℃）

Stability:

Volatile

InChIKey

XDTMQSROBMDMFD-UHFFFAOYSA-N

LogP

3.44 at 20℃

CAS DataBase Reference

110-82-7(CAS DataBase Reference)

NIST Chemistry Reference

Cyclohexane(110-82-7)

EPA Substance Registry System

Cyclohexane (110-82-7)

Safety

Hazard Codes 

F,Xn,N

Risk Statements 

11-38-50/53-65-67-20

Safety Statements 

9-16-25-33-60-61-62

RIDADR 

UN 1145 3/PG 2

OEB

A

OEL

TWA: 300 ppm (1050 mg/m3)

WGK Germany 

2

RTECS 

GU6300000

F 

3-10

Autoignition Temperature

500 °F

TSCA 

Yes

HS Code 

2902 11 00

HazardClass 

3

PackingGroup 

II

Hazardous Substances Data

110-82-7(Hazardous Substances Data)

Toxicity

LC in mice: ~60-70 mg/l air (Lazarew)

IDLA

1,300 ppm [10% LEL]

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

H304May be fatal if swallowed and enters airways

H315Causes skin irritation

H336May cause drowsiness or dizziness

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P233Keep container tightly closed.

P273Avoid release to the environment.

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P331Do NOT induce vomiting.

Cyclohexane Chemical Properties,Usage,Production

Description

Cyclohexane is obtained by the distillation of petroleum or by hydrogenation of benzene. It constitutes 0.5–1.0% of petroleum

Chemical Properties

Cyclohexane is a colorless liquid with a mild, sweet odor.

Physical properties

Colorless liquid with a sweet, chloroform-like odor. A detection odor threshold concentration of 2,700 mg/m³ (784 ppm_v) was experimentally determined by Dravnieks (1974). An odor threshold concentration of 2.7 ppb_v was reported by Nagata and Takeuchi (1990).

Uses

Cyclohexane is a petroleum product obtainedby distilling C4- 400°F boiling rangenaphthas, followed by fractionation andsuperfractionation; also formed by catalytichydrogenation of benzene. It is usedextensively as a solvent for lacquers andresins, as a paint and varnish remover, andin the manufacture of adipic acid, benzene,cyclohexanol, and cyclohexanone.

Uses

Suitable for HPLC, spectrophotometry, environmental testing

Uses

Solvent for lacquers and resins. Paint and varnish remover. In the extraction of essential oils. In analytical chemistry for mol wt determinations (cryoscopic constant 20.3). In the manufacture of adipic acid, benzene, cyclohexyl chloride, nitrocyclohexane, cyclohexanol and cyclohexanone. In the manufacture of solid fuel for camp stoves. In fungicidal formulations (possesses slight fungicidal action). In the industrial recrystallization of steroids.

Production Methods

Cyclohexane is fractionated from crude oil and may be released wherever petroleum products are refined, stored, and used. Another large source of general release is in exhaust gases from motor vehicles. It is prepared synthetically from benzene, by hydrocracking of cyclopentane, or from toluene by simultaneous dealkylation and double bond hydrogenation.

Definition

ChEBI: An alicyclic hydrocarbon comprising a ring of six carbon atoms; the cyclic form of hexane, used as a raw material in the manufacture of nylon.

Definition

A colorless liquid alkane that is commonly used as a solvent and in the production of hexanedioic acid (adipic acid) for the manufacture of nylon. Cyclohexane, itself, is manufactured by the reformation of longer chain hydrocarbons present in crude-oil fractions. It is also interesting from a structural point of view, existing as a ‘puckered’ six-membered ring, having all bonds between carbon atoms at 109.9° (the tetrahedral angle). The molecule undergoes rapid interconversion between two ‘chair-like’ CONFORMATIONS, which are energetically equivalent, passing through a ‘boat-like’ structure of higher energy. It is commonly represented by a hexagon.

Definition

cyclohexane: A colourless liquidcycloalkane, C₆H₁₂; r.d. 0.78; m.p.6.5°C; b.p. 81°C. It occurs in petroleumand is made by passing benzeneand hydrogen under pressureover a heated Raney nickel catalyst at150°C, or by the reduction of cyclohexanone.It is used as a solvent andpaint remover and can be oxidizedusing hot concentrated nitric acid tohexanedioic acid (adipic acid). The cyclohexanering is not planar and canadopt boat and chair conformations;in formulae it is representedby a single hexagon.

General Description

A clear colorless liquid with a petroleum-like odor. Used to make nylon, as a solvent, paint remover, and to make other chemicals. Flash point -4°F. Density 6.5 lb / gal (less than water) and insoluble in water. Vapors heavier than air.

Air & Water Reactions

Highly flammable. Insoluble in water.

Reactivity Profile

Liquid nitrogen dioxide was fed into a nitration column containing hot Cyclohexane, due to an error. An explosion resulted [MCA Case History 128(1962)] Incompatible with strong oxidizers.

Health Hazard

Dizziness, with nausea and vomiting. Concentrated vapor may cause unconsciousness and collapse.

Health Hazard

Cyclohexane is an acute toxicant of loworder. It is an irritant to the eyes and respiratorysystem. Exposure to a 1–2% concentrationin air caused lethargy, drowsiness,and narcosis in test animals. The lethal concentrationfor a 1-hour exposure in mice isestimated at around 30,000 ppm. Ingestionof cyclohexane exhibited low toxic effects intest species. The LD50 values in the literature show a wide variation. It may be detectedfrom its odor at 300 ppm concentration.

Flammability and Explosibility

Highly flammable

Chemical Reactivity

Reactivity with Water: No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.

Safety Profile

Poison by intravenous route, Moderately toxic by ingestion. A systemic irritant by inhalation and ingestion. A skin irritant. Mutation data reported. Flammable liquid. Dangerous fire hazard when exposed to heat or flame; can react with oxidming materials. Moderate explosion hazard in the form of vapor when exposed to flame. When mixed hot with liquid dinitrogen tetraoxide an explosion can result. To fight fire, use foam, CO2, dry chemical, spray, fog. When heated to decomposition it emits acrid smoke and fumes.

Potential Exposure

Cyclohexane is used as a chemical intermediate; as a solvent for fats, oils, waxes, resins, cer- tain synthetic rubbers; and as an extractant of essential oils in the perfume industry.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin,remove contaminated clothing and wash immediately withsoap and water. Seek medical attention immediately. If thischemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart actionhas stopped. Transfer promptly to a medical facility. Whenthis chemical has been swallowed, get medical attention. Donot induce vomiting

Carcinogenicity

No tumor-promoting activity was observed in mice receiving one 60 mL application of 0.3% DMBA in benzene followed by a 60 mL application of cyclohexane twice weekly for 50 weeks.

Source

Schauer et al. (1999) reported cyclohexane in a diesel-powered medium-duty truck exhaust at an emission rate of 210 μg/km.
California Phase II reformulated gasoline contained cyclohexane at a concentration of 8,900 mg/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 1.44 and 238.0 mg/km, respectively (Schauer et al., 2002).

Environmental Fate

Biological. Microbial degradation products reported include cyclohexanol (Dugan, 1972; Verschueren, 1983), 1-oxa-2-oxocycloheptane, 6-hydroxyheptanoate, 6-oxohexanoate, adipic acid, acetyl-CoA, succinyl-CoA (quoted, Verschueren, 1983), and cyclohexanone (Dugan, 1972; Keck et al., 1989).
Photolytic. The following rate constants were reported for the reaction of cyclohexane and OH radicals in the atmosphere: 5.38 x 10^-12 cm³/molecule?sec at 295 K (Greiner, 1970); 6.7 x 10^-12 cm³/molecule?sec at 300 K (Darnall et al., 1978); 6.69 x 10^-12 cm³/molecule?sec at 298 (DeMore and Bayes, 1999); 7.0 x 10^-12 cm³/molecule?sec (Atkinson et al., 1979); 7.49 x 10^-12 cm³/molecule?sec (Atkinson, 1990). A photooxidation reaction rate constant of 1.35 x 10^-16 cm³/molecule?sec was reported for the reaction of cyclohexane with NO3 in the atmosphere (Atkinson, 1991).
Chemical/Physical. The gas-phase reaction of cyclohexane with OH radicals in the presence of nitric oxide yielded cyclohexanone and cyclohexyl nitrate as the major products (Aschmann et al., 1997).
Cyclohexane will not hydrolyze because it has no hydrolyzable functional group.

storage

Color Code—Red: Flammability Hazard: Store ina flammable liquid storage area or approved cabinet awayfrom ignition sources and corrosive and reactive materials.Prior to working with cyclohexane you should be trained onits proper handling and storage. Before entering confinedspace where cyclohexane may be present, check to makesure that an explosive concentration does not exist.Cyclohexane must be stored to avoid contact with oxidizers(such as perchlorates, peroxides, permanganates, chlorates,and nitrates), since violent reactions occur. Store in tightlyclosed containers in a cool well-ventilated area away fromheat. Metal containers involving the transfer of this chemical should be grounded and bonded. Where possible, automatically pump liquid from drums or other storagecontainers to process containers. Drums must be equippedwith self-closing valves, pressure vacuum bungs, and flamearresters. Use only nonsparking tools and equipment, especially when opening and closing containers of this chemical. Sources of ignition, such as smoking and open flames,are prohibited where this chemical is used, handled, orstored in a manner that could create a potential fire orexplosion hazard. Wherever cyclohexane is used, handled,manufactured, or stored, use explosion-proof electricalequipment and fittings.

Shipping

UN1145 Cyclohexane, Hazard Class: 3; Labels: 3-Flammable liquid.

Purification Methods

It is best to purify it by washing with conc H2SO4 until the washings are colourless, followed by water, aqueous Na2CO3 or 5% NaOH, and again water until neutral. It is then dried with P2O5, Linde type 4A molecular sieves, CaCl2, or MgSO4 then Na and distilled. Cyclohexane has been refluxed with, and distilled from Na, CaH2, LiAlH4 (which also removes peroxides), sodium/potassium alloy, or P2O5. Traces of *benzene can be removed by passage through a column of silica gel that has been freshly heated: this gives material suitable for ultraviolet and infrared spectroscopy. If there is much *benzene in the cyclohexane, most of it can be removed by a preliminary treatment with nitrating acid (a cold mixture of 30mL conc HNO3 and 70mL of conc H2SO4) which converts *benzene into nitrobenzene. The impure cyclohexane and the nitrating acid are placed in an ice bath and stirred vigorously for 15minutes, after which the mixture is allowed to warm to 25o during 1hour. The cyclohexane is decanted, washed several times with 25% NaOH, then water, dried with CaCl2, and distilled from sodium. Carbonyl-containing impurities can be removed as described for chloroform. Other purification procedures include passage through columns of activated alumina and repeated crystallisation by partial freezing. Small quantities may be purified by chromatography on a Dowex 710-Chromosorb W gas-liquid chromatographic column. Flammable liquid. [Sabatier Ind Eng Chem 18 1005 1926, Schefland & Jacobs The Handbook of Organic Solvents (Van Nostrand) p592 1953, Beilstein 5 IV 27.] Rapid purification: Distil, discarding the forerun. Stand distillate over Grade I alumina (5% w/v) or 4A molecular sieves.

Toxicity evaluation

If released to air, cyclohexane will exist solely as a vapor in the ambient atmosphere, and will be degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals, though direct photolysis is not expected due to the lack of absorption in the environmental spectrum. Volatilization from water surfaces is expected to be an important fate for this compound, and half-lives in a model river and lake are expected to be 3 h and ～3.5 days respectively. Adsorption to suspended solids and sediments is also expected, though hydrolysis in the environment is unlikely due to the lack of hydrolyzable functional groups.
The potential for bioconcentration and bioaccumulation of cyclohexane in aquatic organisms is moderate. It is highly resistant to biodegradation and is catabolized chiefly by cooxidation.

Incompatibilities

May form explosive mixture with air. Contact with oxidizers, nitrogen dioxide, and oxygen can cause fire and explosion hazard. Can explode in heat when mixed with dinitrogen tetraoxide liquid.

Waste Disposal

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.