74-98-6

Propane is released to the living environment from automobile exhausts, burning furnaces, natural gas sources, and during combustion of polyethylene and phenolic resins. Propane is both highly inflammable and explosive and needs proper care and management of workplaces. Its use in industry includes as a source for fuel and propellant for aerosols. Occupational workers exposed to liquefi ed propane have demonstrated skin burns and frostbite. Propane also causes depression effects on the CNS.

A colorless gas with a faint petroleum-like odor. PROPANE(74-98-6) is shipped as a liquefied gas under its vapor pressure. For transportation PROPANE(74-98-6) may be stenched. Contact with the unconfined liquid can cause frostbite by evaporative cooling. Easily ignited. The vapors are heavier than air and a flame can flash back to the source of leak very easily. The leak may be either a liquid or vapor leak. The vapors can asphyxiate by the displacement of air. Under prolonged exposure to fire or heat the containers may rupture violently and rocket.

PROPANE is incompatible with strong oxidizing agents.

Highly flammable.

Asphyxiant. Flammable, dangerous fire risk, explosive limits in air 2.4–9.5%. For storage, see butane (note).

Vaporizing liquid may cause frostbite. Concentrations in air greater than 10% cause dizziness in a few minutes. 1% concentrations give the same effect in 10 min. High concentrations cause asphyxiation.

Flammable gas. May form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explo- sions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Liquid attacks some plas- tics, rubber and coatings.

Behavior in Fire: Containers may explode. Vapor is heavier than air and may travel a long distance to a source of ignition and flash back.

If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, includ- ing resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medi- cal attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit. If frostbite has occurred, seek medical attention immediately; do NOT rub the affected areas or flush them with water. In order to prevent further tissue damage, do NOT attempt to remove frozen clothing from frostbitten areas. If frostbite has NOT occurred, immediately and thoroughly wash contaminated skin with soap and water.

UN1978 Propane, Hazard Class: 2.1; Labels: 2.1-Flammable gas. UN1075 Petroleum gases, liquefied or Liquefied petroleum gas, Hazard Class: 2.1; Labels: 2.1-Flammable gas. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written permission of the owner.

Return refillable compressed gas cylinders to supplier. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.

Propane is a colorless, odorless, flammable gas that follows methane and ethane in the alkane series. The root word prop comes from the three-carbon acid propionic acid, CH3CH2COOH. Propionic acid comes from the Greek words protos meaning first and pion meaning fat.It was the smallest acid with fatty acid properties. Propane is the gas used to fuel barbecues and camp stoves giving it the common name bottled gas.It is marketed as liquefied petroleum gas (LPG) or liquefied petroleum; it should be noted that LPG is often a mixture that may contains butane, butylene, and propylene in addition to propane. In addition to cooking, propane can be used as an energy source for space heating, refrigeration, transportation, and heating appliances (clothes dryer).
Propane can be stored as liquid in pressurized (approximately 15 atmospheres) storage tanks and/or at cold temperatures and vaporizes to a gas at atmospheric pressure and normal temperatures. This makes it possible to store a large volume of propane as a liquid in a relatively small volume; propane as a vapor occupies 270 times the volume of propane in liquid form. This makes liquid propane an ideal fuel for transport and storage until needed.

Propane demonstrates that the carbon atoms have different characteristics in alkanes with more than two carbon atoms. The terminal carbon atoms in propane are bonded to three hydrogen atoms and one carbon atom. A carbon atom bonded to only one other carbon atom is referred to as a primary or 1° carbon. The central carbon atom in propane is bonded to two other carbon atoms and is called a secondary or 2° carbon. A hydrogen atom has the same classifi cation as the carbon atom to which it is attached. Thus the hydrogen atoms attached to the terminal carbon atoms in propane are called primary (1°) hydrogens, whereas the central atom has secondary (2°) hydrogen. The diff erence in bonds leads to diff erences in reactions and properties of diff erent isomers. For example, breaking a primary bond requires more energy than breaking a secondary bond in propane. This makes formation of the isopropyl radical CH3CHCH3• easier than the n-propyl radical, CH3CH2CH2•. Even though the formation of the isopropyl is more favorable energetically, the greater number of primary hydrogen atoms leads to approximately equal amounts of n-propyl and isopropyl radicals formed under similar reaction conditions.
Oxidation of propane can produce various oxygenated compounds under appropriate conditions, but generally alkanes are relatively unreactive compared to other organic groups. Some of the more common oxidation products include methanol (CH3OH), formaldehyde (CH2O), and acetaldehyde (C2H4O). Propane can be converted to cyclopropane by conversion to 1,3 dichloro-propane using zinc dust and sodium iodine ClCH2CH2CH2Cl--Zn. Nacl--cyclopropane.

ChEBI: Propane is an alkane and a gas molecular entity. It has a role as a food propellant.

In addition to facilitating solubilization of lipids, apolipoproteins help to maintain the structural integrity of lipoproteins, serve as ligands for lipoprotein receptors, and regulate the activity of enzymes involved in lipid metabolism. Apolipoprotein E (ApoE) plays an important role in lipid metabolism. It′s interaction with specific ApoE receptor enables uptake of chylomicron remnants by liver cells, which is an essential step during normal lipid metabolism. It also binds with the LDL receptor (Apo B/E). Defects in ApoE are a cause of hyperlipoproteinemia type III.

Propane is an anesthetic and is nonirritating to the eyes, nose, or throat. Direct skin or mucous membrane contact with liquefied propane causes burns and frostbite. At air concentration levels below 1000 ppm, propane exerts very little physiological action. At very high levels, propane has CNS depressant and asphyxiating properties; its target organ is the central nervous system.

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 propane was 169 mg/kg of pine burned. Emission rates of propane were not measured during the combustion of oak and eucalyptus.
California Phase II reformulated gasoline contained propane at a concentration of 100 mg/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 1.62 and 191 mg/km, respectively (Schauer et al., 2002).

Biological. In the presence of methane, Pseudomonas methanica degraded propane to 1- propanol, propionic acid, and acetone (Leadbetter and Foster, 1959). The presence of carbon dioxide was required for “Nocardia paraffinicum” to degrade propane to propionic acid (MacMichael and Brown, 1987). Propane may biodegrade in two pathways. The first is the formation of propyl hydroperoxide, which decomposes to 1-propanol followed by oxidation to propanoic acid. The other pathway involves dehydrogenation to 1-propene, which may react with water giving propanol (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-propanol). The alcohol may undergo a series of dehydrogenation steps forming an aldehyde (propionaldehyde), then a fatty acid (propionic acid). The fatty acid may then be metabolized by β-oxidation to form the mineralization products carbon dioxide and water (Singer and Finnerty, 1984).
Photolytic. When synthetic air containing propane and nitrous acid was exposed to artificial sunlight (λ = 300–450 nm), propane photooxidized to acetone with a yield of 56% (Cox et al., 1980). The rate constants for the reaction of propane and OH radicals in the atmosphere at 298 and 300 K were 1.11 x 10^-12 cm³/molecule?sec (DeMore and Bayes, 1999) and 1.3 x 10^-12 cm³/molecule?sec (Hendry and Kenley, 1979). Cox et al. (1980) reported a rate constant of 1.9 x 10-12 cm³/molecule?sec for the reaction of gaseous propane with OH radicals based on a value of 8 x 10^-12 cm³/molecule?sec for the reaction of ethylene with OH radicals.
Chemical/Physical. Incomplete combustion of propane in the presence of excess hydrogen chloride resulted in a high number of different chlorinated compounds including, but not limited to alkanes, alkenes, monoaromatics, alicyclic hydrocarbons, and polynuclear aromatic hydrocarbons. Without hydrogen chloride, 13 nonchlorinated polynuclear aromatic hydrocarbons were formed (Eklund et al., 1987).
Complete combustion in air yields carbon dioxide and water.

(vol %):
Alcohol (790 at 16.6 °C and 754 mmHg), benzene (1,452 at 21.5 °C and 757 mmHg), chloroform (1,299 at 21.6 °C and 757 mmHg), ether (926 at 16.6 °C and 757 mmHg), and turpentine (1,587 at 17.7 °C and 757 mmHg) (Windholz et al., 1983).

(vol %):
Alcohol (790 at 16.6 °C and 754 mmHg), benzene (1,452 at 21.5 °C and 757 mmHg), chloroform (1,299 at 21.6 °C and 757 mmHg), ether (926 at 16.6 °C and 757 mmHg), and turpentine (1,587 at 17.7 °C and 757 mmHg) (Windholz et al., 1983).

Purify propane by bromination of the olefinic contaminants. Propane is treated with bromine for 30minutes at 0o. Unreacted bromine is quenched, and the propane is distilled through two -78o traps and collected at -196o [Skell et al. J Am Chem Soc 108 6300 1986]. It autoignites at 450o and the flash point is -104o. It is highly FLAMMABLE and is available in metal cylinders. [Beilstein 1 H 103, 1 I 33, 1 II 71, 1 III 204, 1 IV 175.]

Some sources classify propane as a simple anesthetic, although it can principally be classified as a simple asphyxiant. Concentrations that are high enough to displace oxygen would be expected to cause lightheadedness, loss of consciousness, and possibly death from asphyxiation.