Methane, fact and fiction

Methane, fact and fiction

There are several threads here at ATS that deal with methane and the dangers posed by it. The purpose of this post is to explore what is fact, myth and the dangers to health and the landscape presented by methane in various forms and sources.

First of all methane is not explosive unless it is mixed with oxygen which usually means mixed with oxygen containing air. So the methane that is trapped underground poses no explosion threat as long as it is contained in a closed space without oxygen. The danger of explosion only happens when methane is released into the atmosphere and mixes with air in the proper range of proportions that are considered explosive. Methane at less than 5% in air is at too low a concentration to explode.

I have seen a comment that methane will explode as soon as it is exposed to the air. This is simply not true. It needs a heat source of high enough temperature to ignite and burn or explode. That is usually a spark, lightening or an open flame that it encounters when it is released into the atmosphere.

There are two forms of methane that we have to be concerned with. The first, methane as a pure gas, can burn or explode under the right conditions. The second form we need to concern ourselves with is methane hydrate. This is formed under water at a depth and temperature that makes it combine with the water it encounters as it bubbles out of the sea floor. Most of the methane that was, and still is, being released in the B P Macondo disaster never reaches the surface. It combines with the sea water to form methane ice which is another name for methane hydrate. As long as the methane hydrate remains at a deep enough depth and a low enough temperature it will remain somewhat stable and pose no threat. The danger from methane hydrate is if it is disturbed by some underwater event, such as an earthquake, and “fizzes” somewhat like the CO2 in a soda fizzes when you shake the can. Another way it can be released is if the temperature of the water at the bottom of the sea raises enough to let the methane break its bond with the water. Either of these can lead to a massive release of methane gas that can then rise to the surface and present the same dangers as any other source of methane gas. But it will also be a danger to anything on the surface like a boat that will sink into the bubble, and therefore well under the water, because of a loss of buoyancy. An airplane flying low enough to be caught in the bubble will suffer a similar fate. Methane does not provide the same “lift” to the wings of an airplane so it will stall and drop into the water. The engine will also stop running as well due to a lack of oxygen as the methane displaces it. It is these two things that are now thought by some oceanographers to be the real cause of the disappearance of ships and planes in the Bermuda Triangle and other methane hydrate rich areas of the seas.

As to the danger to health from breathing methane or drinking water with methane in it, it is not toxic. However, if you have a methane infusion into your water or are near a large source of bubbling methane you will most likely have other toxic substances mixed in with the methane. So while the methane itself is not toxic it can be an indicator of the presence of other dangerous substances. In fact, if you ingest water with nothing but pure methane in it the only effect will be a larger supply of gas to pass. The only other health hazard associated with methane is suffocation if you find yourself in a large enough pocket of it to exclude the oxygen in the air.

So where does that leave us? The methane bubbling up out of the ground presents little danger as long as it doesn’t accumulate in a large pocket and release suddenly in one huge burp. The other concern is methane, which is basically the natural gas we use to cook and heat our homes, that is stored in large volumes as highly compressed gas or LNG which is short for Liquefied Natural Gas. The danger with methane in this form is the same as any other bulk stored liquid or gas that can burn or explode. For instance, the 1.5 million barrels of liquid butane that was stored in one of the salt dome caverns.

For back up information for the statements I have made CLICK HERE for an MSDS sheet for methane that will not only support this post but supply you with much more information. I am also posting the data from the same MSDS in the next two posts. The MSDS at the link is formatted better if you want to save or print it.

Here is the MSDS data.

METHANE MATERIAL SAFETY DATA SHEET

SECTION 1. PRODUCT IDENTIFICATION
PRODUCT NAME: Methane FORMULA: CH4
CHEMICAL NAME: Methane, Saturated Alphatic Hydrocarbon, Alkane
SYNONYMS: Methyl Hydride, Marsh Gas, Fire Damp

MANUFACTURER:
Air Products and Chemicals, Inc.
7201 Hamilton Boulevard
Allentown, PA 18195 - 1501
PRODUCT INFORMATION : (800) 752-1597

MSDS NUMBER: 1070 REVISION: 6
REVIEW DATE: July 1999 REVISION DATE: July 1999

SECTION 2. COMPOSITION / INFORMATION ON INGREDIENTS
Methane is packaged as pure product (>99%).

CAS NUMBER: 74-82-8

EXPOSURE LIMITS:
OSHA: None established ACGIH: Simple Asphyxiant NIOSH: None established
SECTION 3. HAZARD IDENTIFICATION

EMERGENCY OVERVIEW
Methane is a flammable, colorless, odorless, compressed gas packaged in cylinders under high
pressure. It poses an immediate fire and explosion hazard when mixed with air at concentrations
exceeding 5.0%. High concentrations that can cause rapid suffocation are within the flammable
range and should not be entered.

EMERGENCY TELEPHONE NUMBERS
800 - 523 - 9374 in Continental U.S. , Canada and Puerto Rico
610 - 481 - 7711 outside U.S.

ACUTE POTENTIAL HEALTH EFFECTS:
ROUTES OF EXPOSURE:

EYE CONTACT: No harmful affect.

INGESTION: Not applicable

INHALATION: Methane is nontoxic. It can, however, reduce the amount of oxygen in the air
necessary to support life. Exposure to oxygen-deficient atmospheres (less than 19.5 %) may
produce dizziness, nausea, vomiting, loss of consciousness, and death. At very low oxygen
concentrations (less than 12 %) unconsciousness and death may occur without warning. It should
be noted that before suffocation could occur, the lower flammable limit for Methane in air will be
exceeded; causing both an oxygen deficient and an explosive atmosphere.

SKIN CONTACT: No harmful affect.

POTENTIAL HEALTH EFFECTS OF REPEATED EXPOSURE:

ROUTE OF ENTRY: None

SYMPTOMS: None
MSDS # 1070 Methane Page 2 of 5
Pub # 320-732

TARGET ORGANS: None

MEDICAL CONDITIONS AGGRAVATED BY OVEREXPOSURE: None

CARCINOGENICITY: Methane is not listed as a carcinogen or potential carcinogen by NTP, IARC, or
OSHA Subpart Z.

SECTION 4. FIRST AID MEASURES

EYE CONTACT: No treatment necessary.

INGESTION: Not applicable

INHALATION: Remove person to fresh air. If not breathing, administer artificial respiration. If
breathing is difficult, administer oxygen. Obtain prompt medical attention.

SKIN CONTACT: No treatment necessary.

NOTES TO PHYSICIAN: Treatment of overexposure should be directed at the control of symptoms and the clinical condition.

SECTION 5. FIRE FIGHTING MEASURES

FLASH POINT: AUTOIGNITION: FLAMMABLE RANGE:
-306 °F (-187.8 C) 999 °F (537 C) 5.0% - 15%

EXTINGUISHING MEDIA: Dry chemical, carbon dioxide, or water.

SPECIAL FIRE FIGHTING INSTRUCTIONS: Evacuate all personnel from area. If possible, without risk, shut off source of methane, then fight fire according to types of materials burning. Extinguish fire only if gas flow can be stopped. This will avoid possible accumulation and re-ignition of a flammable gas mixture. Keep adjacent cylinders cool by spraying with large amounts of water until the fire burns itself out. Self-contained breathing apparatus (SCBA) may be required.

UNUSUAL FIRE AND EXPLOSION HAZARDS: Most cylinders are designed to vent contents when exposed to elevated temperatures. Pressure in a cylinder can build up due to heat and it may rupture if pressure relief devices should fail to function.

HAZARDOUS COMBUSTION PRODUCTS: Carbon monoxide

SECTION 6. ACCIDENTAL RELEASE MEASURES

STEPS TO BE TAKEN IF MATERIAL IS RELEASED OR SPILLED: Evacuate immediate area.
Eliminate any possible sources of ignition, and provide maximum explosion-proof ventilation. Use a flammable gas meter (explosimeter) calibrated for Methane to monitor concentration. Never enter an area where Methane concentration is greater than 1.0% (which is 20% of the lower flammable limit). An immediate fire and explosion hazard exists when atmospheric Methane concentration exceeds 5.0%. Use appropriate protective equipment (SCBA and fire resistant suit). Shut off source of leak if possible. Isolate any leaking cylinder. If leak is from container, pressure relief device or its valve, contact your supplier. If the leak is in the user’s system, close the cylinder valve, safely vent the pressure, and purge with an inert gas before attempting repairs.

SECTION 7. STORAGE AND HANDLING

STORAGE: Store cylinders in a well-ventilated, secure area, protected from the weather. Cylinders should be stored upright with valve outlet seals and valve protection caps in place. There should be no sources of ignition. All electrical equipment should be explosion-proof in the storage areas. Storage areas must meet National Electrical Codes for class 1 hazardous areas. Flammable storage areas must be separated from oxygen and other oxidizers by a minimum distance of 20 ft. or by a barrier of non-combustible material at least 5 ft. high having a fire resistance rating of at least _ hour. Post “No Smoking or Open Flames” signs in the storage or use areas. Do not allow storage temperature to exceed 125 F (52 C). Storage should be away from heavily traveled areas and emergency exits. Full and empty cylinders should be segregated. Use a first-in first-out inventory system to prevent full containers from being stored for long periods of time.

HANDLING: Do not drag, roll, slide or drop cylinder. Use a suitable hand truck designed for cylinder movement. Never attempt to lift a cylinder by its cap. Secure cylinders at all times while in use. Use a pressure reducing regulator to safely discharge gas from cylinder. Use a check valve to prevent reverse flow (MSDS # 1070 Methane Page 3 of 5 Pub # 320-732) into cylinder. Never apply flame or localized heat directly to any part of the cylinder. Do not allow any part of the cylinder to exceed 125 F (52 C). Use piping and equipment adequately designed to withstand pressures to be encountered. Once cylinder has been connected to properly purged and inerted process, open cylinder valve slowly and carefully. If user experiences any difficulty operating cylinder valve, discontinue use and contact supplier. Never insert an object (e.g., wrench, screwdriver, etc.) into valve cap openings. Doing so may damage valve causing a leak to occur. Use an adjustable
strap-wrench to remove over-tight or rusted caps. All piped systems and associated equipment must be grounded. Electrical equipment should be non-sparking or explosion-proof.

SPECIAL PRECAUTIONS: Always store and handle compressed gas cylinders in accordance with Compressed Gas Association, Inc. (telephone 703-412-0900) pamphlet CGA P-1, Safe Handling of Compressed Gases in Containers. Local regulations may require specific equipment for storage or use.

SECTION 8. EXPOSURE CONTROLS/PERSONAL PROTECTION

ENGINEERING CONTROLS:
VENTILATION: Provide adequate natural or explosion-proof ventilation to prevent
accumulation of gas concentrations above 1.0% Methane (20% of LEL).

RESPIRATORY PROTECTION:
Emergency Use: Do not enter areas where Methane concentration is greater than 1.0% (20%
of the LEL). Exposure to concentrations below 1.0% do not require respiratory protection.

EYE PROTECTION: Safety glasses and/or face shield.

SKIN PROTECTION: Leather gloves for handling cylinders. Fire resistant suit and gloves in emergency situations.

OTHER PROTECTIVE EQUIPMENT: Safety shoes are recommended when handling cylinders.

SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES

APPEARANCE, ODOR AND STATE: Colorless, odorless, flammable gas.

MOLECULAR WEIGHT: 16.04

BOILING POINT (1 atm): -258.7 °F (-161.5 C)

SPECIFIC GRAVITY (Air = 1): 0.554

FREEZING POINT / MELTING POINT: -296. 5 °F (-182.5 C)

VAPOR PRESSURE (At 70 F (21.1 C)): Permanent, noncondensable gas.

GAS DENSITY (At 70 F (21.1 C) and 1 atm): 0.042 lb/ft3

SOLUBILITY IN WATER (vol/vol): 3.3 ml gas / 100 ml

SECTION 10. STABILITY AND REACTIVITY

CHEMICAL STABILITY: Stable

CONDITIONS TO AVOID: Cylinders should not be exposed to temperatures in excess of 125 F (52 C).

INCOMPATIBILITY (Materials to Avoid): Oxygen, Halogens and Oxidizers

REACTIVITY:

A) HAZARDOUS DECOMPOSITION PRODUCTS: None

B) HAZARDOUS POLYMERIZATION: Will not occur

SECTION 11. TOXICOLOGICAL INFORMATION

LC50 (Inhalation): Not applicable. Simple asphyxiant.

LD50 (Oral): Not applicable

LD50 (Dermal): Not applicable

SKIN CORROSIVITY: Methane is not corrosive to the skin.

ADDITIONAL NOTES: None
MSDS # 1070 Methane Page 4 of 5
Pub # 320-732

SECTION 12. ECOLOGICAL INFORMATION

AQUATIC TOXICITY: Not determined

MOBILITY: Not determined

PERSISTENCE AND BIODEGRADABILITY: Not determined

POTENTIAL TO BIOACCUMULATE: Not determined

REMARKS: This product does not contain any Class I or Class II ozone depleting chemicals.

SECTION 13. DISPOSAL CONSIDERATIONS

UNUSED PRODUCT / EMPTY CONTAINER: Return container and unused product to supplier. Do not attempt to dispose of residual or unused quantities.

DISPOSAL INFORMATION: Residual product in the system may be burned if a suitable burning unit (flair incinerator) is available on site. This shall be done in accordance with federal, state, and local regulations. Wastes containing this material may be classified by EPA as hazardous waste by characteristic (i.e., Ignitability, Corrosivity, Toxicity, Reactivity). Waste streams must be characterized by the user to meet federal, state, and local requirements.

SECTION 14. TRANSPORT INFORMATION

DOT SHIPPING NAME: Methane, compressed

HAZARD CLASS: 2.1

IDENTIFICATION NUMBER: UN1971

SHIPPING LABEL(s): Flammable gas

PLACARD (When required): Flammable gas

SPECIAL SHIPPING INFORMATION: Cylinders should be transported in a secure upright position in a well-ventilated truck. Never transport in passenger compartment of a vehicle. Ensure cylinder valve is properly closed, valve outlet cap has been reinstalled, and valve protection cap is secured before shipping cylinder.

CAUTION: Compressed gas cylinders shall not be refilled except by qualified producers of compressed gases. Shipment of a compressed gas cylinder which has not been filled by the owner or with the owner’s written consent is a violation of Federal law (49 CFR 173.301).

NORTH AMERICAN EMERGENCY RESPONSE GUIDEBOOK NUMBER (NAERG #): 115

SECTION 15. REGULATORY INFORMATION

U.S. FEDERAL REGULATIONS:

EPA - ENVIRONMENTAL PROTECTION AGENCY

CERCLA: Comprehensive Environmental Response, Compensation, and Liability Act of 1980
(40 CFR Parts 117 and 302) Reportable Quantity (RQ): None

SARA TITLE III: Superfund Amendment and Reauthorization Act

SECTIONS 302/304: Emergency Planning and Notification (40 CFR Part 355)
Extremely Hazardous Substances: Methane is not listed. Threshold Planning Quantity (TPQ): None Reportable Quantity (RQ): None

SECTIONS 311/312: Hazardous Chemical Reporting (40 CFR Part 370)
IMMEDIATE HEALTH: Yes PRESSURE: Yes DELAYED HEALTH: No REACTIVITY: No
FIRE: Yes

SECTION 313: Toxic Chemical Release Reporting (40 CFR Part 372)
Methane does not require reporting under Section 313. MSDS # 1070 Methane Page 5 of 5

Nice post,op.
I could be mistaken,and correct me if I am wrong,but I think you did miss one important detail.

(PhysOrg.com) -- The release of massive amounts of carbon from methane hydrate frozen under the seafloor 56 million years ago has been linked to the greatest change in global climate since a dinosaur-killing asteroid presumably hit Earth 9 million years earlier. New calculations by researchers at Rice University show that this long-controversial scenario is quite possible. Nobody knows for sure what started the incident, but there's no doubt Earth's temperature rose by as much as 6 degrees Celsius. That affected the planet for up to 150,000 years, until excess carbon in the oceans and atmosphere was reabsorbed into sediment. Earth's ecosystem changed and many species went extinct during the Paleocene-Eocene Thermal Maximum (PETM) 56 million years ago, when at least 2,500 gigatonnes of carbon, eventually in the form of carbon dioxide, were released into the ocean and atmosphere. (The era is described in great detail in a recent National Geographic feature.) A new report by Rice scientists in Nature Geoscience suggests that at the time, even though methane-containing gas hydrates – the "ice that burns" – occupied only a small zone of sediment under the seabed before the PETM, there could have been as much stored then as there is now. Read more at: phys.org...

reply to post by kdog1982


I had considered including that but my main focus was the current dangers from the sinkhole and the B P disaster. However, I did mention the possibility of a similar event if there is an earthquake or a breach of the seabed from the pressure under it that disturbs the methane hydrate on the gulf floor. It could become a disaster of biblical proportions and bring about another extinction level event if a chain reaction is triggered from the gulf that spreads out to the Atlantic ocean. In fact some paleontologists believe that at least one of the pre historic extinctions was caused by just such a release. Then all it would take is one lightening strike to set it off and create a massive conflagration. Talk about your "scorched earth"!!!

I am updating this thread to include new material I wrote for another thread HERE. While some of the material is already covered in this thread, there is also some new material and some new insights into the methane hydrate problem.

The following is the text from the other reply...

I posted an extensive thread HERE to deal with the specific dangers posed by the direct release of methane from the bayous. It covers some of what I am going to post here as well but I am going to try to go into greater detail to more adequately cover the different nature of methane hydrate being discussed in this thread.

First we have to understand how methane hydrate is created in nature and how it is kept stable. Most of the ocean floor, and smaller bodies of water like the gulf, have methane gas constantly bubbling out of fissures in the sea bed. In fact there are many places on land where there are shallow bodies of water, like the Louisiana Bayous, that are also constantly bubbling methane.

So the question now becomes "Why is methane hydrate formed in some places and not others?". And the answer is...

It takes both low temperatures and extreme pressures for the methane to combine with water and form methane hydrate. Shallow bodies of water on land simply don't meet those requirements.

If you were keeping tabs on the B P Deepwater Horizon well failure there was a perfect visual example of methane hydrate being formed. In most of the videos taken underwater by the ROV's around the leaking well there was something many people didn't understand and asked questions about. What I am talking about is the wispy shreds of material that were constantly floating gently down to the gulf bed. They looked like mucus strands or like shredded cloth floating all around the well site and at other places in the gulf sea floor where considerable quantities of methane were leaking.

What was actually happening is that the methane was trying to float to the surface as a gas. But most of it never made it to the surface because the cold and pressure a mile under the gulf was forcing the methane to combine with the water and form methane hydrate. If you remember, even though there were massive amounts of methane leaking out from the well along with the oil, as well as from the gulf floor around the well, there was very little, if any, bubbling at the surface like there is in the Louisiana bayous. That is because nearly all the methane was being converted to methane hydrate, otherwise known as methane ice before it could reach the surface.

Think of the rising and falling action of a lava lamp. But with the methane it is the methane, which is lighter than water, rising and forming methane hydrate, which is slightly heavier than water, which then sinks back down to the sea bed. The analogy isn't perfect since the material in the lava lamp is driven to rise and fall in a continuous cycle driven by the heat of the lamp and the cooling of the material as it rises away from the lamp. But with the methane / methane hydrate the cycle is closed ended and is complete when the methane hydrate falls back down.

Now lets address what it is that keeps the methane hydrate from separating back into methane gas and water. Another nearly, but not quite perfect, analogy to explain it is to look at the CO2 in a can of carbonated soda. The CO2 is forced into solution with the water of the soda by a machine that exposes the water to the CO2 under high pressure. And just like the soda, where CO2 is made to dissolve in the water, both pressure and temperature play a role in forming it and keeping it that way. A very cold can of soda will remain fizzy longer than a warm soda. Also, if you take a can of warm soda and shake it vigorously before opening it as soon as you pop the tab the CO2 will violently erupt out of solution and you get a soda shower.

Now we can begin to see what we are facing with the huge amounts of methane hydrate on the floors of every deep cold body of water. Since the pressure at depth will not change we have to look at the other variable, temperature. And we have been seeing in the news that water temperatures are increasing considerably in some parts of the worlds bodies of water.

Even at stable temperatures and pressures some of the methane hydrate will convert back to gas if sufficiently disturbed by an under water quake. Alternately, a new hot water or lava vent can warm the methane hydrate in the area enough to cause a gas eruption.

But with the warming of the waters we are seeing the temperature variable changing enough to allow massive chain reaction releases of methane even with a relatively minor disturbance.

reply to post by happykat39

The methane bubbling up out of the ground presents little danger as long as it doesn’t accumulate in a large pocket and release suddenly in one huge burp.

This is incorrect. It doesn't need to ignite to be added in the atmosphere as a greenhouse gas. The potential for methane hydrates to being released from the oceans pools as we continue to pollute the atmosphere with CO2 is very real, and very threatening to the survival of civilization in the years and decades to come.

Industry dumps CO2 in the atmosphere, and this acts as a shield to bounce rays back to earth, many of which hit the ocean. So it warms up. The CO2 falls over the years, and is dumped into the oceans, causing it to acidify, and warm up even more. Eventually the warming causing a tipping point, and methane is released. This release acts as an even greater shield which will rise cause an estimated average rise on earth from 6-12 centigrade.

That means ecosystem collapses. It means most of the food chain dies off. It means if we don't counter this, or mitigate the damage with innovative solutions quick enough, most of us die out as well when governments and communities fail.

Originally posted by unityemissions
reply to post by happykat39

 

The methane bubbling up out of the ground presents little danger as long as it doesn’t accumulate in a large pocket and release suddenly in one huge burp.

This is incorrect. It doesn't need to ignite to be added in the atmosphere as a greenhouse gas. The potential for methane hydrates to being released from the oceans pools as we continue to pollute the atmosphere with CO2 is very real, and very threatening to the survival of civilization in the years and decades to come.

Industry dumps CO2 in the atmosphere, and this acts as a shield to bounce rays back to earth, many of which hit the ocean. So it warms up. The CO2 falls over the years, and is dumped into the oceans, causing it to acidify, and warm up even more. Eventually the warming causing a tipping point, and methane is released. This release acts as an even greater shield which will rise cause an estimated average rise on earth from 6-12 centigrade.

That means ecosystem collapses. It means most of the food chain dies off. It means if we don't counter this, or mitigate the damage with innovative solutions quick enough, most of us die out as well when governments and communities fail.

In the long run you are correct. However, I originally wrote this in response to concerns over the relatively small emissions around the bayous in assumption Parish in Louisiana. And the point being made was that levels that posed no suffocation danger were not harmful since methane by itself is not a toxic or poisonous substance. If you examine the MSDS above you will see that there are no health hazards related to methane exposure below suffocation levels.

However, as you state, methane in the quantities we can expect if warming of the oceans continues will present several very real dangers. And one of these dangers is an extinction level event should enough of the worlds supply of underwater methane be released in a short time. In fact I do mention somewhere in the above material that some scientists believe that at least one of the prehistoric extinctions was caused by just such a sudden and massive release. If that happens again civilization as we know it will cease to exist. There would almost certainly be small pockets of humanity that would survive but they would be sent back to being hunter gatherers.