ethane

H220: Extremely flammable gas [Danger Flammable gases]

P203, P210, P222, P280, P377, P381, and P403 (click each P-code to see the statement)

H220 (99.7%): Extremely flammable gas [Danger Flammable gases]

H280 (60.3%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]

H281 (17.3%): Contains refrigerated gas; may cause cryogenic burns or injury [Warning Gases under pressure]

P203, P210, P222, P280, P282, P336+P317, P377, P381, P403, and P410+P403 (click each P-code to see the statement)

Aggregated GHS information provided per 647 reports by companies from 15 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H280: Contains gas under pressure; may explode if heated [Warning Gases under pressure]

H281: Contains refrigerated gas; may cause cryogenic burns or injury [Warning Gases under pressure]

H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

P203, P210, P222, P261, P271, P280, P282, P304+P340, P319, P336+P317, P377, P381, P403, P403+P233, P405, P410+P403, and P501 (click each P-code to see the statement)

Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.

ON FROSTBITE: rinse with plenty of water, do NOT remove clothes. Refer for medical attention .

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

Remove from exposure; support respiration. (USCG, 1999)

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

Refer to the "General First Aid" section. Specific First Aid: Clothing frozen to the skin should be thawed before being removed. In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. (ERG, 2024)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· Clothing frozen to the skin should be thawed before being removed.

· In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts.

· In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).

SMALL FIRE: Dry chemical or CO2.

LARGE FIRE: Water spray or fog. If it can be done safely, move undamaged containers away from the area around the fire. CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.

FIRE INVOLVING TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out. In other cases extinguish with water spray, powder. In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position.

Wear self contained breathing apparatus for fire fighting if necessary.

Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Use water spray to cool unopened containers.

To fight fire stop flow of gas.

For more Fire Fighting Procedures (Complete) data for ETHANE (7 total), please visit the HSDB record page.

Flashback along vapor trail may occur.

Under fire conditions the cylinders may violently rupture and rocket.

... As a result of flow, agitation, etc, electrostatic charges can be generated ... On loss of containment ... /ethane/ can cause suffocation by lowering the oxygen content of the air in confined areas ... Rapid evaporation of the liquid may cause frostbite.

· 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.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Many gases are heavier than air and will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).

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

· All equipment used when handling the product must be grounded.

· Do not touch or walk through spilled material.

· Stop leak if you can do it without risk.

· If possible, turn leaking containers so that gas escapes rather than liquid.

· Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.

· Do not direct water at spill or source of leak.

CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors.

· Prevent spreading of vapors through sewers, ventilation systems and confined areas.

· Isolate area until gas has dispersed.

CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning.

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 800 meters (1/2 mile).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE - Safety Precautions" section. (ERG, 2024)

Immediate precautionary measure

· Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

Large Spill

· Consider initial downwind evacuation for at least 800 meters (1/2 mile).

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions.

· In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE - Safety Precautions" section.

Evacuate danger area! Consult an expert! Personal protection: self-contained breathing apparatus. Ventilation. Remove all ignition sources. NEVER direct water jet on liquid.

Evacuate danger area! Consult an expert! Personal protection: self-contained breathing apparatus. Ventilation. Remove all ignition sources. NEVER direct water jet on liquid.

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.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock down vapors.

Evacuation: ... If material leaking (not on fire) consider evacuation from downwind area based on amt of material spilled, location, and weather conditions.

Personnel protection: Avoid breathing vapors. Keep upwind. Do not handle broken packages unless wearing appropriate personal protective equipment. Approach fire with caution.

NO open flames, NO sparks, and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (eg, by grounding) if in liquid state. Use non-sparking handtools.

For more Preventive Measures (Complete) data for ETHANE (6 total), please visit the HSDB record page.

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors. Prevent spreading of vapors through sewers, ventilation systems and confined areas. Isolate area until gas has dispersed. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning. (ERG, 2024)

Fireproof. Cool. Separated from strong oxidants and halogens.

Keep container tightly closed in a dry and well-ventilated place.

Storage temp: -128 °F; venting: safety relief

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

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

· Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.

3000 [ppm]

33000 [ppm]

200000 [ppm]

Minimal Oxygen Content. ACGIH recommends a minimal ambient oxygen partial pressure of 132 torr, which is protective against inert oxygen-displacing gases and oxygen-consuming processes for altitudes up to 5000 feet.

· DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED.

CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)

Small Fire

· Dry chemical or CO2.

Large Fire

· Water spray or fog.

· If it can be done safely, move undamaged containers away from the area around the fire.

CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.

Fire Involving Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Cool containers with flooding quantities of water until well after fire is out.

· Do not direct water at source of leak or safety devices; icing may occur.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

· For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

On loss of containment this substance can cause suffocation by lowering the oxygen content of the air in confined areas.

Rapid evaporation of the liquid may cause frostbite.

Self-contained breathing apparatus for high vapor concentrations. (USCG, 1999)

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids. (ERG, 2024)

Self contained breathing apparatus for high vapor concn.

Cold-insulating gloves. Protective clothing.

Skin and body protectio: In Impervious clothing., Flame retardant antistatic protective clothing, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

Eye protection: Face shield and safety glasses Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

For more Personal Protective Equipment (PPE) (Complete) data for ETHANE (6 total), please visit the HSDB record page.

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (e.g., by grounding) if in liquid state. Use non-sparking handtools.

Use ventilation, local exhaust or breathing protection.

Wear face shield.

Ethane appears as a colorless odorless gas. It is easily ignited. The vapors are heavier than air. It can asphyxiate by the displacement of air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Contact with the liquid may cause frostbite.

Ethane, refrigerated liquid appears as a colorless odorless very cold liquid. Boils at -88.6 °C. Easily ignited and a flame can flash back to the source of a leak very easily. Vapors are heavier than air. Vapors can asphyxiate by the displacement of air from enclosed spaces. Direct contact can cause frostbite. Contact of very cold liquid with water may result in vigorous or violent boiling. If the water is hot, there is the possibility that a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if liquid gas contacts water in a closed container. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Used in manufacturing other chemicals.

Liquid; Gas Vapor

Colorless, odorless gas; [Merck Index]

COLOURLESS COMPRESSED LIQUEFIED GAS. ODOURLESS WHEN PURE.

Colorless gas

Odorless

-127.5 °F at 760 mmHg (USCG, 1999)

-88.6 °C

-88.6 °C @760 [mm Hg]

-279.9 °F (USCG, 1999)

-182.794 °C

-211 °F (USCG, 1999)

-135 °C (-211 °F) - closed cup

Flammable gas

In water, 60.2 mg/L at 25 °C

60.4 ug/mL water at 20 °C

46 mL/100 mL alcohol at 4 °C

Very soluble in benzene

Soluble in ether

60.2 mg/L @ 25 °C (exp)

Solubility in water, ml/100ml at 20 °C: (very poor)

0.546 at -127.48 °F (USCG, 1999) - Less dense than water; will float

1.0493 at 0 °C/4 °C (air = 1) or 1.3562 g/L; 0.446 at 0 °C/4 °C (liquid)

% IN SATURATED AIR: 100 AT 25 °C, 760 MM HG; DENSITY OF AIR SATURATED WITH VAPOR: 1.04 AT 25 °C, 760 MM HG (AIR= 1)

0.446 as liq

1.04 (Air = 1)

Relative vapor density (air = 1): 1.05

VP: 1 Pa at -183.3 °C (solid); 10 Pa at -173.2 °C; 100 Pa at -161.3 °C; 1 kPa at -145.3 °C; 10 kPa at -122.8 °C; 100 kPa at -88.8 °C

Vapor pressure, kPa at 20 °C: 3850

760 [mm Hg]

log Kow = 1.81

940 °F (USCG, 1999)

882 °F (472 °C)

6.4 at 200 K; 9.4 at 300 K; 12.2 at 400 K; 14.8 at 500 K; 18.1 at 600 K (all in uPa.s)

1727 btu/cu ft at 25 °C

5.16 kJ/mol at 25 °C

16 dynes/cm = 0.016 N/m at -88 °C

8.99X10+2 ppm (detection in water, purity not specified)

Odor index @ 20 °C= 25300 ppm

Highly flammable.

Hydrocarbons, Aliphatic Saturated

Highly Flammable

Saturated aliphatic hydrocarbons, such as ETHANE, may be incompatible with strong oxidizing agents like nitric acid. Charring of the hydrocarbon may occur followed by ignition of unreacted hydrocarbon and other nearby combustibles. In other settings, aliphatic saturated hydrocarbons are mostly unreactive. They are not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents. Peroxidizable

ETHANE, REFRIGERATED LIQUID is relatively inactive chemically except for its flammability.

Chlorine dioxide mixed with ... ethane ... always explodes spontaneously.

Incompatible with chlorine, dioxygenyl tetrafluoroborate, oxidizing materials, heat or flame.

Interaction /between chlorine and/ ... ethane over activated carbon at 350 °C has caused explosions, but added carbon dioxide reduces the risk ... The violent interaction of liquid chlorine injected into ethane at 80 °C/10 bar becomes very violent if ethylene is also present ...

Strong oxidizing agents

... A mixture prepared at -196 °C with either methane or ethane exploded when the temp was raised to -78 °C.

The substance can be absorbed into the body by inhalation.

Suffocation.

ON CONTACT WITH LIQUID: FROSTBITE.

Neurotoxin - Acute solvent syndrome

Other Poison - Simple Asphyxiant

FIRST AID: Skin--ON CONTACT WITH LIQUID FROSTBITE: rinse with plenty of water, do NOT remove clothes. Refer for medical attention; Eyes--ON CONTACT WITH LIQUID FROSTBITE. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Aliphatic hydrocarbons and related compounds/

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Treat frostbite with rapid rewarming techniques ... ./Aliphatic hydrocarbons and related compounds/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously.Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aliphatic hydrocarbons and related compounds/

For more Antidote and Emergency Treatment (Complete) data for ETHANE (7 total), please visit the HSDB record page.

/SIGNS AND SYMPTOMS/ Ethane is considered to be physiologically and toxicologically inert. At high concn, ethane acts primarily as a simple asphyxiant by displacing oxygen from the blood and air. Oxygen deprivation and asphyxiation eventually lead to unconsciousness and death.

/SIGNS AND SYMPTOMS/ Skin /and/ Eyes ON CONTACT WITH /ethane/ LIQUID: FROSTBITE.

/SIGNS AND SYMPTOMS/ On loss of containment ... /ethane/ can cause suffocation by lowering the oxygen content of the air in confined areas ... Rapid evaporation ... may cause frostbite ... ...

/OTHER TOXICITY INFORMATION/ From a toxicologic standpoint, methane and ethane are of low anesthetic potency and are practically inert; however, at very high concentrations, they act as a simple asphyxiant and can cause suffocation by displacement of oxygen from breathing atmosphere, below the critical level of 16% oxygen that is required to sustain life.

/LABORATORY ANIMALS: Acute Exposure/ Guinea pigs exposed to 2.2 to 5.5% for 2 hr show slight signs of irregular respiration, which is readily reversible on cessation of the exposure.

/LABORATORY ANIMALS: Acute Exposure/ Cardiac arrhythmia was studied in dogs following inhalation of ethane ... at high concentrations. Although the criteria used for cardiac arrhythmia may have differed between studies, all exposures resulted in responses indicative of cardiac arrhythmia. In one study, cardiac arrhythmia, observed as multifocal ventricular tachycardia, occurred in dogs exposed to ethane (2 of 4 dogs) ... The specific exposure was not defined for the hydrocarbon gases studied; however, a range of 150,000 to 900,000 ppm for gaseous compounds was cited.

/ALTERNATIVE and IN VITRO TESTS/ Methods were developed for exposing Syrian hamster embryo cells in vitro to ethane gas. After exposure, the cells were removed and assayed for viability and increased sensitivity to viral transformation. Ethane was determined to be inactive.

/OTHER TOXICITY INFORMATION/ The inhibitory action of compressed hydrocarbon gases on the growth of the yeast Saccharomyces cerevisiae was investigated quantitatively by microcalorimetry. Both the 50% inhibitory pressure (IP(50)) and the minimum inhibitory pressure (MIP), which are regarded as indices of the toxicity of hydrocarbon gases, were determined from growth thermograms. Based on these values, the inhibitory potency of the hydrocarbon gases increased in the order methane << ethane < propane < i-butane < n-butane. The toxicity of these hydrocarbon gases correlated to their hydrophobicity, suggesting that hydrocarbon gases interact with some hydrophobic regions of the cell membrane. In support of this, /the authors/ found that UV absorbing materials at 260 nm were released from yeast cells exposed to compressed hydrocarbon gases. Additionally, scanning electron microscopy indicated that morphological changes occurred in these cells.

/OTHER TOXICITY INFORMATION/ Ethane does not have anesthetic properties. At concentrations of 15 to 90%, ethane is able to sensitize the canine myocardium to cardiac arrhythmias induced by epinephrine.

Ethane's production and use as a compound in the manufacture of ethylene by high-temperature thermal cracking, as a feedstock in the production of vinyl chloride, in the synthesis of chlorinated hydrocarbons, as a refrigerant, and as a component of fuel gas (so-called bottled gas or suburban propane) may result in its release to the environment through various waste streams. Emissions from the combustion of gasoline, foliar fuels, polyethylene, and waste incinerators may also contribute to its direct release into the environment. Ethane is a constituent in the paraffin fraction of crude oil and natural gas. If released to air, a vapor pressure of 3.15X10+4 mm Hg at 25 °C indicates ethane will exist solely as a gas in the atmosphere. Gas-phase ethane will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 60 days. Based on data for iso-octane and n-hexane, ethane is not expected to absorb UV light at wavelengths >290 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight. If released to soil, ethane is expected to have very high mobility based upon an estimated Koc of 37. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 0.5 atm-cu m/mole. Ethane will volatilize from dry soil surfaces based upon its vapor pressure. Ethane was oxidized to ethanol in lake water and soil within 24 hours using cell suspensions from over 20 methyltrophic organisms. This suggests that biodegradation may be an important fate process in the environment; however, ethane is a gas and therefore volatilization is expected to be the dominant fate process. If released into water, ethane is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 1.6 hours and 2.2 days, respectively. An estimated BCF of 7.3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions (pH 5 to 9). Occupational exposure to ethane may occur through inhalation and dermal contact with this compound at workplaces where ethane is produced or used. Atmospheric workplace exposures have been documented. The most likely pathway by which the general public is exposed to ethane is by inhalation due to the release of this substance from natural gas and crude oil emissions. Ethane is widely detected in air. (SRC)

Ethane is a constituent in the paraffin fraction of crude oil and natural gas(1).

Ethane's production and use as a compound in the manufacture of ethylene by high-temperature thermal cracking; as a feedstock in the production of vinyl chloride; in the synthesis of chlorinated hydrocarbons; as a refrigerant; and as a component of fuel gas (so-called bottled gas or suburban propane)(1) may result in its release to the environment through various waste streams(SRC). Emissions from the combustion of gasoline(2-4), foliar fuels(5), polyethylene(6), and waste incinerators(7) may also contribute to its direct release into the environment.

Typical ethane emissions were as follows: diesel engine: 1.8% of emitted hydrocarbons; reciprocating engine: 2.0% of emitted hydrocarbons; rotary gasoline engine: 1.3% of emitted hydrocarbons; expected ground level concentration in USA urban air: 0.05-0.50 ppm; in flue gas of municipal incinerator: < 0.4-0.5 ppm; in gasoline engine exhaust: 1.8% of emitted hydrocarbons(1). Flue gases from a waste incinerator were found to contain ethane at concentrations generally less than 0.5 ppm(2). Ethane was detected at <3 ug/L in dissolved gases from a former landfill(3).

Anaerobic transformations of 1,1,1-trichloroethane (TCA), 1,1-dichloroethane (DCA), and chloroethane (CA) were studied with sludge from a lab-scale, municipal wastewater sludge digester. TCA was biologically transformed to DCA and CA and further to ethane by reductive dechlorination. TCA was also converted to acetic acid and 1,1-dichloroethene (11DCE) by cell-free extract. 11DCE was further biologically converted to ethene. This pathway was confirmed by transformation tests of TCA, DCA and CA, by tests with cell-free extract, and by chloride release during TCA degradation. With cell-free extract, acetic acid accounted for approximately 90% of the TCA transformed; tests with live cells indicate that the fraction of TCA transformed by this pathway decreased with lower biomass. The dechlorination of DCA to CA and CA to ethane was not stoichiometric. A high rate of TCA removal was observed under the experimental conditions. The results indicate that removal of TCA in anaerobic digestion should be complete, but DCA and CA could persist in a normally operating digester.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 37(SRC), determined from a log Kow of 1.81(2) and a regression-derived equation(3), indicates that ethane is expected to have very high mobility in soil(SRC). Volatilization of ethane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.5 atm-cu m/mole(SRC), derived from its vapor pressure, 3.15X10+4 mm Hg(4), and water solubility, 60.2 mg/L(5). Ethane is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Ethane was oxidized to ethanol in lake water and soil within 24 hours using cell suspensions from over 20 methyltrophic organisms(6,7). This suggests that biodegradation may be an important fate process in the environment; however, ethane is a gas and therefore volatilization is expected to be the dominant fate process(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 37(SRC), determined from a log Kow of 1.81(2) and a regression-derived equation(3), indicates that ethane is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon an estimated Henry's Law constant of 0.5 atm-cu m/mole(SRC), derived from its vapor pressure, 3.15X10+4 mm Hg(5), and water solubility, 60.2 mg/L(6). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 1.6 hours and 2.2 days, respectively(SRC). According to a classification scheme(7), an estimated BCF of 7.3(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Ethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). Ethane was oxidized to ethanol in lake water and soil within 24 hours using cell suspensions from over 20 methyltrophic organisms(8,9). This suggests that biodegradation may be an important fate process in the aquatic environment; however, ethane is a gas and therefore volatilization is expected to be the dominant fate process(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), ethane, which has a vapor pressure of 3.15X10+4 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase ethane 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 60 days(SRC), calculated from its rate constant of 2.68X10-13 cu cm/molecule-sec at 25 °C(3). Based on data for iso-octane and n-hexane, ethane is not expected to absorb UV light at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

AEROBIC: Within 24 hr, ethane was oxidized to its corresponding alcohol, ethanol, by cell suspensions of over 20 methyltrophic organisms isolated from lake water and soil samples(1,2). The respective gas exchange and degradation rate constants were 0.83X10-5 sq cm sec-1 and 0.027 day-1 for ethane contained in a model estuarine ecosystem at 10 °C and a salinity of 30 parts per thousand; the corresponding biodegradation half-life was greater than 87 days(3). At 20 °C and a salinity of 30, the respective gas exchange and degradation rate constants were 1.132X10-5 sq cm sec-1 and 0.062 day-1; the corresponding biodegradation half life for n-ethane ranged from 21 to 33 days(3).

Estimated lifetime under photochemical smog conditions in SE England: 137 hr

The rate constant for the gas-phase reaction of ethane with photochemically-produced hydroxyl radicals has been measured as 2.68X10-13 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 60 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). Other rate constants measured for this reaction were 3.08X10-13(3), 3.06X10-13(4), 2.90X10-13(5), 2.67X10-13(6), and 2.28X10-13(4), which correspond to atmospheric half-lives of 52, 52, 55, 60, and 70 days, respectively(2). Experimental data showed that less than 1.4% of the ethane fraction in a dark chamber reacted with NOx to form the corresponding alkyl nitrate(7,8), suggesting nighttime reactions with radical species and nitrogen oxides may contribute to the atmospheric transformation of ethane. The rate constant for the gas-phase reaction of ethane with nitrate radicals was measured to be 7.9X10-18 cu cm/molecule-sec at 25 °C(9). Ethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(10). Based on data for iso-octane and n-hexane, ethane is not expected to absorb UV light at wavelengths >290 nm(11) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). An air sample's ethane concentration of 191 ppbC was reduced by only 2% within 6 hours of irradiation by natural sunlight in downtown Los Angeles, CA(11). The estimated lifetime of ethane under photochemical smog conditions in southeast England was 137 hours(12).

An estimated BCF of 7.3 was calculated in fish for ethane(SRC), using a log Kow of 1.81(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of ethane is estimated as 37(SRC), using a log Kow of 1.81(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that ethane is expected to have very high mobility in soil.

Ethane is a gas and therefore volatilization from soil and water is expected to be the most important fate process. The Henry's Law constant for ethane is estimated as 0.5 atm-cu m/mole(SRC) derived from its vapor pressure, 3.15X10+4 mm Hg(1), and water solubility, 60.2 mg/L(2). This Henry's Law constant indicates that ethane is expected to volatilize rapidly from water surfaces(3). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 1.6 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 2.2 days(SRC). Ethane's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Volatilization of ethane from dry soil surfaces will occur(SRC) based upon its vapor pressure(1).

SEAWATER: All 8 near surface sea water samples collected from the intertropical Indian Ocean contained ethane at concentrations ranging from 5.68 to 36.07 nL of gas/L(1). Ethane was detected in 3 of 7 surface water samples from the Gulf of Mexico ranging in concentration from less than 1 to 90 nL/L with an average concentration of 35 nL/L(2). Ethane was detected in Mid-Atlantic sea water at concentrations ranging from 13-221 pmol/L(3). Ethane is emitted to the air from the Mid-Atlantic at a rate ranging from 0.41-4.3 X10+8 molec/sq cm-sec(3).

RAIN/SNOW/FOG: Ethane was detected at a maximum concentration of 4 ppbV in arctic snow pack(1).

Flue gases from a waste incinerator at Babylon, Long Island, NY were found to contain ethane at concentration generally less than 0.5 ppm(1). Ethane is also a product of gasoline(2-4), natural gas(4), and polyethylene(5) combustion. The average exhaust from 67 gasoline fueled vehicles was found to contain ethane at a concentration of 1.2% by weight of total hydrocarbon(3). Ethane from car exhaust ranged in concentration from 0.32 to 0.93 ppmV with an average for 8 samples of 0.53 ppmV(4). A Texaco refinery located in Tulsa, OK attributed emissions to the surrounding atmosphere where the ethane concentration was measured to be 33.8 and 73.5 ppbC for two minutes before and after 1:33PM(6). The ethane content of the air downwind of a Mobil natural gas facility in Rio Blanco, CO was 136.1 ppbC(6). Underwater hydrocarbon vent discharges from offshore oil production platforms were found to contain ethane concentration in the vapor phase at 2600 umol/L of gas(7). Gas-phase emissions from open burning of six fine (foliar) fuels, loblolly pine, western hemlock, ponderosa pine, mixed hardwood forest foliage litter, Florida palmetto/slash pine, and wiregrass/longleaf pine, contained ethane at rates of 505.6, 338.2, 500.3, 334.3, 315.0, and 259.5 mg/kg of biomass burned, respectively(8).

Ethane was detected in the gas phase of a Los Angeles tunnel at 119 mg/L(1). Ethane was detected in a tunnel in Antwerp, Belgium at a concentration of 166 ug/cu m(2), which is about 5 times greater than the background ethane levels of 30 ug/cu m(2). In a study of volatile organic contaminants in tunnels, ethane was found in the Cassiar tunnel in Vancouver in 1993 and 1995, as well as Tuscorora, Caldecott and Ft Mc Henry tunnels at concentrations of 0.92, 0.025, 0.93, 0.69 and 0.72 respectively(3). Ethane was released from cars driving in urban, suburban, rural and motor ways were observed as 26.25, 14.87, 11.16 and 10.65 mg/km(4). Ethane detections in exhaust had a mean concentration of 0.21 ppm(5). Ethane was detected with annual means of 1-2 ug/cu m in London background, 4 ug/cu m curbside and annual mean ranging from 4-25 ug/cu m in European cities(5). Ethane was detected at a median concentration of 21.4 ppbC from 1984-1986 in 39 US cities(6). In a study of reformulated gasoline in California, ethane, which accounted for 0% by weight of the gasoline, was found to account for 1.5% of nonmethane organic tunnel emissions(7).

Ethane accounted for 0.01, 0.01 and 0.02% of emissions from regular, mid-grade, and premium vehicle emissions, respectively, and 1.81 and 4.38% of the emissions from roadways and refineries, respectively(1). Ethane accounted for 0.86 and 0.01% of the emissions from regular summer blend gasoline in Atlanta and Chicago, respectively(1). Ethane accounted for 1.3 and 1.2% of the total VOC concentrations of low oxygenate and high oxygenate gasoline, respectively(2). In non-catalytic engines, ethane was released at concentrations of 13.27 and 12.6 mg/km for reference and reformulated fuels, respectively(3). In 3-way catalytic engines, ethane was released at concentrations 9.63 and 8.59 mg/km for reference and reformulated fuels, respectively(3). Ethane accounted for 3.1% vehicle emissions and 4.8% petroleum refineries(4). The MS Aurora and Stena Danica ferries operating in the Skagerak-Kattegatt-Oresund region of Sweden, release ethane at a concentration of <0.6 mg/cu nm dry weight(5).

SEDIMENT: Ethane was detected in 10 of 10 sediment samples from Walvis Bay of the Namibian shelf of SW Africa at concentrations of 4.4, 4.1, 3.6, 2.8, 2.5, 5.0, 1.9, 2.0, 2.5, and 2.3 ng/g(1). Sediments from the Bering Sea contained ethane gas at concentrations ranging from 7 to 510 nL/L(2).

URBAN/SUBURBAN: The average ethane concentration for 2 samples per 4 sites in Tulsa, OK was 19.2 ppbC with a range of 2.3 to 73.5 ppbC(1). The ethane concentrations for 6 sites in Rio Blanco, CO averaged 27.0 ppbC with a range from 4.6 to 136.1(1). Ethane was detected in 20 of 20 air samples from Houston, TX ranging in concentration from 13.8 to 751.8 ppm with an average of 124.2 ppm(2). The arithmetic and geometric means were 54.2 and 44.2 ppbC, respectively, for the atmospheric ethane content at urban locations in New England(3). The ground level atmospheric concentration of ethane at 13:25 was 79 ppb and 406 ppb at 08:00 for Huntington Park, CA(4). At 1500 ft the ethane concentration was 43 ppb at 07:43 and at 08:07 at a height of 2,200 ft the ethane concentration was 39 ppb(4). The ethane concentration ranged from 32 to 221 ppbV at a downtown Los Angeles location during the Fall of 1981(5). The ethane concentration at 1100 ft just east of Antioch, CA was 11.5 ug/cu m, at 1000 ft near Pittsburg, CA was 7.0 ug/cu m, at 1100 ft over Carquinez Strait, CA was 5.5 ug/cu m and at 1000 ft over San Pablo Bay, CA was 4.0 ug/ cu m(6). Ethane was detected in Atlanta, GA in 1992 with an average concentration of 101.1 ppb(7). The ethane concentrations were 3.5, 3.0, and 2.5 ug/cu m at 10, 15, and 40 miles downwind of Janesville, WI on August 14, 1978(8). According to the National Ambient Volatile Organic Compounds (VOCs) Database, the median urban and suburban atmospheric concentrations of ethane were 9.150 ppbV for 571 samples and 15.780 ppbV for 226 samples,respectively(9).

Ethane's production and use as a compound in the manufacture of ethylene by high-temperature thermal cracking, as a feedstock in the production of vinyl chloride, in the synthesis of chlorinated hydrocarbons, as a refrigerant, and as a component of fuel gas (so-called bottled gas or suburban propane) may result in its release to the environment through various waste streams. Emissions from the combustion of gasoline, foliar fuels, polyethylene, and waste incinerators may also contribute to its direct release into the environment. Ethane is a constituent in the paraffin fraction of crude oil and natural gas. If released to air, a vapor pressure of 3.15X10+4 mm Hg at 25 °C indicates ethane will exist solely as a gas in the atmosphere. Gas-phase ethane will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 60 days. Based on data for iso-octane and n-hexane, ethane is not expected to absorb UV light at wavelengths >290 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight. If released to soil, ethane is expected to have very high mobility based upon an estimated Koc of 37. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 0.5 atm-cu m/mole. Ethane will volatilize from dry soil surfaces based upon its vapor pressure. Ethane was oxidized to ethanol in lake water and soil within 24 hours using cell suspensions from over 20 methyltrophic organisms. This suggests that biodegradation may be an important fate process in the environment; however, ethane is a gas and therefore volatilization is expected to be the dominant fate process. If released into water, ethane is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 1.6 hours and 2.2 days, respectively. An estimated BCF of 7.3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions (pH 5 to 9). Occupational exposure to ethane may occur through inhalation and dermal contact with this compound at workplaces where ethane is produced or used. Atmospheric workplace exposures have been documented. The most likely pathway by which the general public is exposed to ethane is by inhalation due to the release of this substance from natural gas and crude oil emissions. Ethane is widely detected in air. (SRC)

Ethane is a constituent in the paraffin fraction of crude oil and natural gas(1).

Ethane's production and use as a compound in the manufacture of ethylene by high-temperature thermal cracking; as a feedstock in the production of vinyl chloride; in the synthesis of chlorinated hydrocarbons; as a refrigerant; and as a component of fuel gas (so-called bottled gas or suburban propane)(1) may result in its release to the environment through various waste streams(SRC). Emissions from the combustion of gasoline(2-4), foliar fuels(5), polyethylene(6), and waste incinerators(7) may also contribute to its direct release into the environment.

Typical ethane emissions were as follows: diesel engine: 1.8% of emitted hydrocarbons; reciprocating engine: 2.0% of emitted hydrocarbons; rotary gasoline engine: 1.3% of emitted hydrocarbons; expected ground level concentration in USA urban air: 0.05-0.50 ppm; in flue gas of municipal incinerator: < 0.4-0.5 ppm; in gasoline engine exhaust: 1.8% of emitted hydrocarbons(1). Flue gases from a waste incinerator were found to contain ethane at concentrations generally less than 0.5 ppm(2). Ethane was detected at <3 ug/L in dissolved gases from a former landfill(3).

Anaerobic transformations of 1,1,1-trichloroethane (TCA), 1,1-dichloroethane (DCA), and chloroethane (CA) were studied with sludge from a lab-scale, municipal wastewater sludge digester. TCA was biologically transformed to DCA and CA and further to ethane by reductive dechlorination. TCA was also converted to acetic acid and 1,1-dichloroethene (11DCE) by cell-free extract. 11DCE was further biologically converted to ethene. This pathway was confirmed by transformation tests of TCA, DCA and CA, by tests with cell-free extract, and by chloride release during TCA degradation. With cell-free extract, acetic acid accounted for approximately 90% of the TCA transformed; tests with live cells indicate that the fraction of TCA transformed by this pathway decreased with lower biomass. The dechlorination of DCA to CA and CA to ethane was not stoichiometric. A high rate of TCA removal was observed under the experimental conditions. The results indicate that removal of TCA in anaerobic digestion should be complete, but DCA and CA could persist in a normally operating digester.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 37(SRC), determined from a log Kow of 1.81(2) and a regression-derived equation(3), indicates that ethane is expected to have very high mobility in soil(SRC). Volatilization of ethane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.5 atm-cu m/mole(SRC), derived from its vapor pressure, 3.15X10+4 mm Hg(4), and water solubility, 60.2 mg/L(5). Ethane is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Ethane was oxidized to ethanol in lake water and soil within 24 hours using cell suspensions from over 20 methyltrophic organisms(6,7). This suggests that biodegradation may be an important fate process in the environment; however, ethane is a gas and therefore volatilization is expected to be the dominant fate process(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 37(SRC), determined from a log Kow of 1.81(2) and a regression-derived equation(3), indicates that ethane is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon an estimated Henry's Law constant of 0.5 atm-cu m/mole(SRC), derived from its vapor pressure, 3.15X10+4 mm Hg(5), and water solubility, 60.2 mg/L(6). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 1.6 hours and 2.2 days, respectively(SRC). According to a classification scheme(7), an estimated BCF of 7.3(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Ethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). Ethane was oxidized to ethanol in lake water and soil within 24 hours using cell suspensions from over 20 methyltrophic organisms(8,9). This suggests that biodegradation may be an important fate process in the aquatic environment; however, ethane is a gas and therefore volatilization is expected to be the dominant fate process(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), ethane, which has a vapor pressure of 3.15X10+4 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase ethane 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 60 days(SRC), calculated from its rate constant of 2.68X10-13 cu cm/molecule-sec at 25 °C(3). Based on data for iso-octane and n-hexane, ethane is not expected to absorb UV light at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

AEROBIC: Within 24 hr, ethane was oxidized to its corresponding alcohol, ethanol, by cell suspensions of over 20 methyltrophic organisms isolated from lake water and soil samples(1,2). The respective gas exchange and degradation rate constants were 0.83X10-5 sq cm sec-1 and 0.027 day-1 for ethane contained in a model estuarine ecosystem at 10 °C and a salinity of 30 parts per thousand; the corresponding biodegradation half-life was greater than 87 days(3). At 20 °C and a salinity of 30, the respective gas exchange and degradation rate constants were 1.132X10-5 sq cm sec-1 and 0.062 day-1; the corresponding biodegradation half life for n-ethane ranged from 21 to 33 days(3).

Estimated lifetime under photochemical smog conditions in SE England: 137 hr

The rate constant for the gas-phase reaction of ethane with photochemically-produced hydroxyl radicals has been measured as 2.68X10-13 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 60 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). Other rate constants measured for this reaction were 3.08X10-13(3), 3.06X10-13(4), 2.90X10-13(5), 2.67X10-13(6), and 2.28X10-13(4), which correspond to atmospheric half-lives of 52, 52, 55, 60, and 70 days, respectively(2). Experimental data showed that less than 1.4% of the ethane fraction in a dark chamber reacted with NOx to form the corresponding alkyl nitrate(7,8), suggesting nighttime reactions with radical species and nitrogen oxides may contribute to the atmospheric transformation of ethane. The rate constant for the gas-phase reaction of ethane with nitrate radicals was measured to be 7.9X10-18 cu cm/molecule-sec at 25 °C(9). Ethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(10). Based on data for iso-octane and n-hexane, ethane is not expected to absorb UV light at wavelengths >290 nm(11) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). An air sample's ethane concentration of 191 ppbC was reduced by only 2% within 6 hours of irradiation by natural sunlight in downtown Los Angeles, CA(11). The estimated lifetime of ethane under photochemical smog conditions in southeast England was 137 hours(12).

An estimated BCF of 7.3 was calculated in fish for ethane(SRC), using a log Kow of 1.81(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of ethane is estimated as 37(SRC), using a log Kow of 1.81(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that ethane is expected to have very high mobility in soil.

Ethane is a gas and therefore volatilization from soil and water is expected to be the most important fate process. The Henry's Law constant for ethane is estimated as 0.5 atm-cu m/mole(SRC) derived from its vapor pressure, 3.15X10+4 mm Hg(1), and water solubility, 60.2 mg/L(2). This Henry's Law constant indicates that ethane is expected to volatilize rapidly from water surfaces(3). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 1.6 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 2.2 days(SRC). Ethane's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Volatilization of ethane from dry soil surfaces will occur(SRC) based upon its vapor pressure(1).

SEAWATER: All 8 near surface sea water samples collected from the intertropical Indian Ocean contained ethane at concentrations ranging from 5.68 to 36.07 nL of gas/L(1). Ethane was detected in 3 of 7 surface water samples from the Gulf of Mexico ranging in concentration from less than 1 to 90 nL/L with an average concentration of 35 nL/L(2). Ethane was detected in Mid-Atlantic sea water at concentrations ranging from 13-221 pmol/L(3). Ethane is emitted to the air from the Mid-Atlantic at a rate ranging from 0.41-4.3 X10+8 molec/sq cm-sec(3).

RAIN/SNOW/FOG: Ethane was detected at a maximum concentration of 4 ppbV in arctic snow pack(1).

Flue gases from a waste incinerator at Babylon, Long Island, NY were found to contain ethane at concentration generally less than 0.5 ppm(1). Ethane is also a product of gasoline(2-4), natural gas(4), and polyethylene(5) combustion. The average exhaust from 67 gasoline fueled vehicles was found to contain ethane at a concentration of 1.2% by weight of total hydrocarbon(3). Ethane from car exhaust ranged in concentration from 0.32 to 0.93 ppmV with an average for 8 samples of 0.53 ppmV(4). A Texaco refinery located in Tulsa, OK attributed emissions to the surrounding atmosphere where the ethane concentration was measured to be 33.8 and 73.5 ppbC for two minutes before and after 1:33PM(6). The ethane content of the air downwind of a Mobil natural gas facility in Rio Blanco, CO was 136.1 ppbC(6). Underwater hydrocarbon vent discharges from offshore oil production platforms were found to contain ethane concentration in the vapor phase at 2600 umol/L of gas(7). Gas-phase emissions from open burning of six fine (foliar) fuels, loblolly pine, western hemlock, ponderosa pine, mixed hardwood forest foliage litter, Florida palmetto/slash pine, and wiregrass/longleaf pine, contained ethane at rates of 505.6, 338.2, 500.3, 334.3, 315.0, and 259.5 mg/kg of biomass burned, respectively(8).

Ethane was detected in the gas phase of a Los Angeles tunnel at 119 mg/L(1). Ethane was detected in a tunnel in Antwerp, Belgium at a concentration of 166 ug/cu m(2), which is about 5 times greater than the background ethane levels of 30 ug/cu m(2). In a study of volatile organic contaminants in tunnels, ethane was found in the Cassiar tunnel in Vancouver in 1993 and 1995, as well as Tuscorora, Caldecott and Ft Mc Henry tunnels at concentrations of 0.92, 0.025, 0.93, 0.69 and 0.72 respectively(3). Ethane was released from cars driving in urban, suburban, rural and motor ways were observed as 26.25, 14.87, 11.16 and 10.65 mg/km(4). Ethane detections in exhaust had a mean concentration of 0.21 ppm(5). Ethane was detected with annual means of 1-2 ug/cu m in London background, 4 ug/cu m curbside and annual mean ranging from 4-25 ug/cu m in European cities(5). Ethane was detected at a median concentration of 21.4 ppbC from 1984-1986 in 39 US cities(6). In a study of reformulated gasoline in California, ethane, which accounted for 0% by weight of the gasoline, was found to account for 1.5% of nonmethane organic tunnel emissions(7).

Ethane accounted for 0.01, 0.01 and 0.02% of emissions from regular, mid-grade, and premium vehicle emissions, respectively, and 1.81 and 4.38% of the emissions from roadways and refineries, respectively(1). Ethane accounted for 0.86 and 0.01% of the emissions from regular summer blend gasoline in Atlanta and Chicago, respectively(1). Ethane accounted for 1.3 and 1.2% of the total VOC concentrations of low oxygenate and high oxygenate gasoline, respectively(2). In non-catalytic engines, ethane was released at concentrations of 13.27 and 12.6 mg/km for reference and reformulated fuels, respectively(3). In 3-way catalytic engines, ethane was released at concentrations 9.63 and 8.59 mg/km for reference and reformulated fuels, respectively(3). Ethane accounted for 3.1% vehicle emissions and 4.8% petroleum refineries(4). The MS Aurora and Stena Danica ferries operating in the Skagerak-Kattegatt-Oresund region of Sweden, release ethane at a concentration of <0.6 mg/cu nm dry weight(5).

SEDIMENT: Ethane was detected in 10 of 10 sediment samples from Walvis Bay of the Namibian shelf of SW Africa at concentrations of 4.4, 4.1, 3.6, 2.8, 2.5, 5.0, 1.9, 2.0, 2.5, and 2.3 ng/g(1). Sediments from the Bering Sea contained ethane gas at concentrations ranging from 7 to 510 nL/L(2).

URBAN/SUBURBAN: The average ethane concentration for 2 samples per 4 sites in Tulsa, OK was 19.2 ppbC with a range of 2.3 to 73.5 ppbC(1). The ethane concentrations for 6 sites in Rio Blanco, CO averaged 27.0 ppbC with a range from 4.6 to 136.1(1). Ethane was detected in 20 of 20 air samples from Houston, TX ranging in concentration from 13.8 to 751.8 ppm with an average of 124.2 ppm(2). The arithmetic and geometric means were 54.2 and 44.2 ppbC, respectively, for the atmospheric ethane content at urban locations in New England(3). The ground level atmospheric concentration of ethane at 13:25 was 79 ppb and 406 ppb at 08:00 for Huntington Park, CA(4). At 1500 ft the ethane concentration was 43 ppb at 07:43 and at 08:07 at a height of 2,200 ft the ethane concentration was 39 ppb(4). The ethane concentration ranged from 32 to 221 ppbV at a downtown Los Angeles location during the Fall of 1981(5). The ethane concentration at 1100 ft just east of Antioch, CA was 11.5 ug/cu m, at 1000 ft near Pittsburg, CA was 7.0 ug/cu m, at 1100 ft over Carquinez Strait, CA was 5.5 ug/cu m and at 1000 ft over San Pablo Bay, CA was 4.0 ug/ cu m(6). Ethane was detected in Atlanta, GA in 1992 with an average concentration of 101.1 ppb(7). The ethane concentrations were 3.5, 3.0, and 2.5 ug/cu m at 10, 15, and 40 miles downwind of Janesville, WI on August 14, 1978(8). According to the National Ambient Volatile Organic Compounds (VOCs) Database, the median urban and suburban atmospheric concentrations of ethane were 9.150 ppbV for 571 samples and 15.780 ppbV for 226 samples,respectively(9).

URBAN/SUBURBAN: Ethane was detected in the atmospheres of Pretoria, Johannesburg and Durban, South Africa(1). Ethane was identified in the ambient air of Sydney, Australia(2) ranging in concentration from 0.8 to 42.4 ppbV with an average concentration of 9.4 ppbV(3). Ethane was detected at an average concentration of 124.9 ppbC in the atmosphere over the British Columbia Research Council Laboratory at the University of British Columbia(4). The average ethane concentration in the air over Tokyo, Japan in 1980 and 1981 were 2.7 and 2.4 ppb for 66 and 192 samples, respectively(5). At Deuselbach, Hunsruck in Germany, the atmospheric ethane concentration was 1.55 ppb for October 23 1983(6). The minimum, maximum and average ethane concentrations in the ambient air of Bombay, India were 1.4, 355.7 and 26.7 ppb, respectively(7). Ethane was detected in urban Australia at a concentration of 7.5 ppb(8). In 1990 ethane comprised 1.68% of UK volatile emissions based on mass(9). Ethane was detected in Tapei, Taiwan, Chicago, IL and Osaka, Japan at concentrations of 8.3, 6.4 and 24.3 ppbV, respectively(10). Ethane was detected in 100% of the urban areas tested with a mean concentration of 5.37 ppb(11). Ethane was detected in rural (Fohnau), residential (Nansen Strasse) and street (Frankfurter Alee) sites in Berlin, Germany at concentrations of 2.59, 4.87 and 7.11 ug cu m, respectively(12). Ethane was detected in Edmonton, Alberta, Canada at median concentrations 10.13 and 11.66 ug/cu m in downtown and industrial areas, respectively(13). Ethane was detected in Vienna, Austria (1988), Sydney, Australia (1982), Chicago, IL (1989) and Osaka, Japan (1993) in average concentrations of 28.3, 7.5, 6.4 and 24.3 ppbV, respectively(14).

INDOOR: Ethane was detected in the air at the 6th floor of the Cooper Union Building, at street level and the 82nd floor of the Empire State Building, at the World Trade Buildings and the Interstate Sanitation Commission in New York City, NY at 6:00-9:00AM, 9:00-11:00AM and 1:00-3:00PM, in July 1978(1). Ethane was detected at an average concentration of 12.3 ug/cu m for 5 samples collected at the 82nd floor of the World Trade Center in New York City between 5:00AM - 5:30PM Aug 23, 1977(2).

RURAL/REMOTE: The respective median, minimum, and maximum atmospheric concentrations of ethane for 5 rural locations in North Carolina ranged from 2.6 to 9.1, 1.1 to 7.2, and 2.6 to 13.0 ppb(1). The atmospheric concentration of ethane for Jones State Forest, TX ranged from 17.7 to 38.4 ppb with an average of 27.1 ppb for 10 samples(2). The arithmetic and geometric means were 14.9 and 6.4 ppbC, respectively, for the atmospheric ethane content at rural locations in New England(3). Forest hydrocarbon emissions near Baton Rouge, Louisiana had background ethane levels of 5-35 ppbv(4). Ethane was detected at concentration of 2.3 ppbC in Everglades Florida(5). For 9 samples collected over a 30 hour period, the average ethane concentration in the Smokey Mountains, NC was 11.4 ppbC with a range from 8.6 to 16.0 ppbC(6). On Aug 27, 1976, the average ethane concentration for air over Lake Michigan at altitudes of 2000, 2500, and 3000 ft was 7.5 ppbV(7). On Aug 28, 1976, the average ethane concentration for air over Lake Michigan at altitudes of 1000 and 1500 ft was 2.3 ppbV(7). Ethane was detected at concentrations ranging from 0.86 to 2.1 ppbv, with an average concentration of 1.27 ppbv, in ambient air samples collected from a rural site at the summit of Whiteface Mountain in New York in July 1994(8). According to the National Ambient Volatile Organic Compounds (VOCs) Database, the median rural and remote atmospheric concentrations of ethane were 3.821 ppbV for 33 samples and 2.095 ppbV for 10 samples, respectively(9).

For more Atmospheric Concentrations (Complete) data for ETHANE (6 total), please visit the HSDB record page.

Ethane is released from burning fireplace hard and softwood as well as hard stove wood in concentrations of 468.1, 662.88 and 1,425.67 mg/kg(1).

According to the 2006 TSCA Inventory Update Reporting data, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of ethane is 1000 or greater; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 56,749 workers (2,699 of these were female) were potentially exposed to ethane in the US(1). Occupational exposure to ethane may occur through inhalation and dermal contact with this compound at workplaces where ethane is produced or used. The most probably route of exposure to ethane is by inhalation; atmospheric workplace exposures have been documented(2). Ethane is widely detected in air. The most likely pathway by which the general public is exposed to ethane is by inhalation due to the release of this substance from natural gas and crude oil emissions(SRC).

AIR INTAKE: According to the National Ambient Volatile Organic Compounds (VOCs) Database, the median urban atmospheric concn of ethane is 9.150 ppbV for 571 samples. Based upon this figure and the value for average daily inhalation by a human adult of 20 cu m of air, the average daily intake of ethane via air is 183 mg(1).

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.

/GUIDE 115: GASES - FLAMMABLE (INCLUDING REFRIGERATED LIQUIDS)/ Fire or Explosion: EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. ... Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. /Ethane; Ethane, compressed; Ethane, refrigerated liquid/

/GUIDE 115: GASES - FLAMMABLE (INCLUDING REFRIGERATED LIQUIDS)/ Health: Vapors may cause dizziness or asphyxiation without warning. Some may be irritating if inhaled at high concentrations. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating and/or toxic gases. /Ethane; Ethane, compressed; Ethane, refrigerated liquid/

/GUIDE 115: GASES - FLAMMABLE (INCLUDING REFRIGERATED LIQUIDS)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. /Ethane; Ethane, compressed; Ethane, refrigerated liquid/

/GUIDE 115: GASES - FLAMMABLE (INCLUDING REFRIGERATED LIQUIDS)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids. /Ethane; Ethane, compressed; Ethane, refrigerated liquid/

For more DOT Emergency Guidelines (Complete) data for ETHANE (8 total), please visit the HSDB record page.

UN 1035; Ethane

UN 1961; Ethane, refrigerated liquid

IMO 2.1; Ethane; Ethane, refrigerated liquid

49 057 31; Ethane (liquified petroleum gas, not elsewhere classified, compressed)

49 057 32; Ethane, liquid (refrigerated)

49 057 33; Ethane propane mixture, liquid (refrigerated)

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Flammable Gas

Symbol: F+; R: 12; S: (2)-9-16-33

UN Hazard Class: 2.1