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What is Methyl Mercaptan?
CBS News ^ | Jan 8, 2007

Posted on 01/08/2007 2:31:09 PM PST by presidio9

According to the ATSDR Agency for Toxic Substances and Disease Registry’s Website, Methyl mercaptan is a colorless gas with a smell like rotten cabbage. It is a natural substance found in the blood, brain, and other tissues of people and animals. It is released from animal feces. It occurs naturally in certain foods, such as some nuts and cheese.Methyl mercaptan is released from decaying organic matter in marshes and is present in the natural gas of certain regions in the United States, in coal tar, and in some crude oils. It is manufactured for use in the plastics industry, in pesticides, and as a jet fuel additive. It is also released as a decay product of wood in pulp mills.

It is also known as Methanethiol.

What is Methanethiol Used For? According to Wikipedia Online Encyclopedia, Methanethiol is primarily used as an odorant to add warning properties to propane and natural gas used as fuel. Propane by itself is odorless, as are many sources of natural gas. Methanethiol is added for safety reasons so that gas leaks are readily noted by anyone present due to the odor. Methanethiol vaporizes readily and is odoriferous enough that only small quantities need be used.

For propane, liquid methanethiol is mixed with liquid propane by the refinery. Methanethiol remains in solution in the desired concentration as the propane is piped and trucked through the distribution system until it is stored in the tank from which it will be used. Propane tanks are usually configured to withdraw vapor rather than liquid, and since the boiling point of methanethiol is somewhat higher than that of propane (and since its vapor pressure is lower), methanethiol becomes more concentrated in the tank as vapor is withdrawn. For this reason, even minute leaks in a piping system connected to a nearly-empty tank produce the characteristic odor, especially if much of the propane was

In natural gas systems, methanethiol is injected into the distribution piping, usually within several miles or less of the point of use. Injection equipment and a tank of methanethiol can be seen at the master meter point outside many cities. Methanethiol tanks are similar in construction to tanks used for propane and anhydrous ammonia. Because of its reactivity, methanethiol can be removed from the gas before it reaches the point of use, or after leaking out of piping. It can react with or be absorbed by metallic pipe materials, particularly when corroded, and will bind to soil particles. Explosions have occurred where underground gas leaks went unnoticed because methanethiol was filtered out by the soil.

Methanethiol is also manufactured for use in the plastics industry, as a precursor in the manufacture of pesticides, and as a jet fuel additive. It is also released as a decay product of wood in pulp mills.

What happens to meethyl mercaptan when it enters the environment? According to the ATSDR -Methyl mercaptan is released to the air from both natural and industrial sources. -Most of the methyl mercaptan released to the environment goes into the air. -Sunlight can break it down in the air to other substances. -Methyl mercaptan may be formed in water from chemical reactions. -It occurs naturally in soil.

How might I be exposed to methyl mercaptan? According to the ATSDR -Methyl mercaptan is always present in your body. -You may breathe it in the air if you live near a natural source of the gas, such as a marsh. -You may eat it in certain foods, such as nuts and cheese. -You may be exposed if you work at a wood-pulp mill or sewage treatment plant. -You could also be exposed if you work in a factory that uses it to make other products such as jet fuel, pesticides, or poultry feed.

How can methyl mercaptan affect my health? According to the ATSDR, very little is known about the health effects of methyl mercaptan. The only information available is about a worker exposed to very high levels of this compound when he opened and emptied tanks of this compound. He developed anemia, went into a coma, and died about a month later. We do not know whether long-term exposure to low levels of methyl mercaptan can result in harmful health effects.

How likely is methyl mercaptan to cause cancer? According to the ATSDR, there is no information available about whether methyl mercaptan causes cancer in people or animals. The Department of Health and Human Services (DHHS), the International Agency for Research on Cancer (IARC), and the EPA have not classified methyl mercaptan for carcinogenicity.

Is there a medical test to show whether I've been exposed to methyl mercaptan? According to the ATSDR, Methyl mercaptan is always present in your body. There is a test that can be used to find out if it is present in your blood at levels that are higher than normal. This test requires special equipment and is not usually available in a doctor's office. It can be done in a special laboratory. However, this test cannot be used to find out how much methyl mercaptan you were exposed to or to predict whether harmful health effects will occur.

Has the federal government made recommendations to protect human health? According to the ATSDR, the EPA requires that discharges, spills, or accidental releases of 100 pounds or more of methyl mercaptan must be reported to the EPA.

The Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit of 20 milligrams of methyl mercaptan per cubic meter of air (20 mg/m³) for an 8-hour workday in a 40-hour workweek.

The American Conference of Governmental and Industrial Hygienists (ACGIH) and the National Institute for Occupational Safety and Health (NIOSH) recommend an occupational exposure limit of 1 mg/m³ for methyl mercaptan.

The federal recommendations have been updated as of July 1999.

(© MMVII, CBS Broadcasting Inc. All Rights Reserved.)


TOPICS: Miscellaneous; News/Current Events; US: New Jersey; US: New York; War on Terror
KEYWORDS: njfarts
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1 posted on 01/08/2007 2:31:10 PM PST by presidio9
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To: stevie_d_64

I had this overwhelming urge to ping you to this, I'm not sure why...


2 posted on 01/08/2007 2:33:18 PM PST by thackney (life is fragile, handle with prayer)
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To: presidio9

They put the smell in there


3 posted on 01/08/2007 2:35:34 PM PST by ndt
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To: presidio9
anyone present due to the odor.

Why would anyone want to be present due to the odor?
You'd think the odor would have the opposite effect.

4 posted on 01/08/2007 2:36:50 PM PST by ASA Vet (The WOT should have been over on 9/12/01.)
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To: thackney

My firm's specialty is cleaning mercaptan containers, particularly methyl mercaptan.


5 posted on 01/08/2007 2:36:55 PM PST by Spirochete
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To: presidio9

As it oxidizes in your body [and rather rapidly], there's not much harm to be expected from low-level exposure. If you can smell it no longer, but it is around, that means that the concentration is getting high, and the best you could do is to get a gas mask or get yourself out of there.


6 posted on 01/08/2007 2:37:58 PM PST by GSlob
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To: presidio9
Noxious Smell over Manhattan caused by Cheese eating villagers. Nuts also to blame. ;^)
7 posted on 01/08/2007 2:38:28 PM PST by pipecorp ( Al Lahsucks boat steersman hell)
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To: thackney

Julean!


8 posted on 01/08/2007 2:39:10 PM PST by GoforBroke
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To: presidio9; Cindy

Ping!


9 posted on 01/08/2007 2:39:27 PM PST by fanfan ("We don't start fights my friends, but we finish them, and never leave until our work is done."PMSH)
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To: presidio9
What is Mercaptan?

??????

10 posted on 01/08/2007 2:42:12 PM PST by jdm
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To: Spirochete

Sounds like an episode of dirty jobs...


11 posted on 01/08/2007 2:43:04 PM PST by Kimmers (It's not what you take when you leave this world behind, it's what you leave behind when you go)
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To: presidio9

Isn't mercaptan what makes skunks smell like they do?


12 posted on 01/08/2007 2:44:32 PM PST by CPOSharky (Year = 365 days. muzzy 'most holy' days = 450. Go figure.)
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To: thackney

Scratch and sniff...

But seriously, I can imagine that with increased exposure and levels of saturation in the air that it does displace breathable air/oxygen to the point where it can dibilitate you over time...

I've already been asked if I was in NYC today...And in Sugarland...

I am not Santa Claus!!! I cannot move that fast people!!!

Thanks for the ping "Mr. T"


13 posted on 01/08/2007 2:49:24 PM PST by stevie_d_64 (Houston Area Texans (I've always been hated))
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To: presidio9

Methyl mercaptan is what makes your urine smell like sulfur after eating asparagus.


14 posted on 01/08/2007 2:53:24 PM PST by oblomov (Progress is precisely that which the rules and regulations did not foresee. - von Mises)
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To: stevie_d_64
"I can imagine that with increased exposure and levels of saturation in the air that it does displace breathable air/oxygen to the point where it can dibilitate you over time... "
It would saturate hemoglobin and cause asphyxiation way before it displaces oxygen. Luckily, it oxidises even in air, so its half-life is limited. By stinking the place with ammonia the oxidation rate of mercaptans can be increased further.
15 posted on 01/08/2007 2:58:11 PM PST by GSlob
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To: presidio9

The debri was taken to Fresh Kills. Maybe all the jet fuel didn't burn off.

http://positron.jfet.org/wtc-fk/
Fresh Kills Landfill is part of Arthur Kills, the area owned by GAF, an affiliate of I.G. Farben.

http://www.colorantshistory.org/GeneralAnilineLinden.html
Some pics of the area is on this site.


16 posted on 01/08/2007 3:03:29 PM PST by Calpernia (Breederville.com)
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To: Velveeta; firebrand; Fedora; The Spirit Of Allegiance; Coleus; backhoe; cyborg; hineybona; Cindy; ..

The WTC site debri was taken to Fresh Kills.

See my thoughts here:

http://www.freerepublic.com/focus/news/1764340/posts?page=16#16


17 posted on 01/08/2007 3:04:46 PM PST by Calpernia (Breederville.com)
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To: jdm

What is...Myrrh-Captain? :-)


18 posted on 01/08/2007 3:06:37 PM PST by Riley (The Fourth Estate is the Fifth Column.)
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To: presidio9

Sounds like it's derived from Ethel Mertz, whatever it is.


19 posted on 01/08/2007 3:12:44 PM PST by RegulatorCountry
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To: presidio9

Oooh that smell........


20 posted on 01/08/2007 3:12:51 PM PST by showme_the_Glory (No more rhyming, and I mean it! ..Anybody want a peanut.....)
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