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Benzene Exposure Alters Endocrine Activity

ncbi.nlm.nih.gov

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Re: Benzene Exposure Alters Endocrine Activity

#141

Post by rrrrrrrrrrrryan »

sharadov wrote: post #134
zinclozenge wrote: post #60

When I was taking organic chemistry my (mid-to-late 60s at the time in ~20010) teacher told us an anecdote about benzene when we started learning about aromatic molecules. She told us that they used to clean their lab bench with benzene solvent to make it sparkling clean. Of course, she also told us it was carcinogenic and then finished by saying a lot of her contemporary colleagues that went into organic chemistry r…

When I was in high school there was this bottle with Mercury floating in it. We would put it in our hands and mess with it. Mercury has this viscous texture and breaks up and coagulates. Only later did I find out how toxic it is.

My parents literally rubbed mercury into their open wounds as children in the 60s. Mercurochrome was a tremendously popular antiseptic, and wasn't banned in the USA until 1998.

Re: Benzene Exposure Alters Endocrine Activity

#142

Post by jabl »

Robotbeat wrote: post #110
wil421 wrote: post #100

Earlier quoted context omitted.

It’s 0.62% or less for gas.[1] [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7918986/#:~:tex... .

No, 0.62% is the average : Benzene content in gasoline is federally regulated, with any refineries or importers required to average less than or equal to 0.62% benzene by volume.” The very next sentence in your link mentions it can have up to 2%, as I mentioned: “Generally, gasoline in the United States is likely to contain 0.5%–2.0% benzene by volume [14,15].” 18% of gasoline’s weight is the BTEX aromatics, benzene,…

Interesting that the regulations are done that way in terms of both an average and a maximum. I wonder how the average is determined, how many samples, and what is the size of a batch etc.?

> 18% of gasoline’s weight is the BTEX aromatics, benzene, toluene, ethylene-benzene, and xylene. https://www.fuelfreedom.org/is-there-a-better-gasoline-addit....

> This may be done depending on the season to increase the octane of gasoline.

> An average of 18% of these aromatics is not what I’d call just trace amounts…

Yes, BTEX is added to improve octane. It's also possible to increase octane by alkylation and isomerization, which produce branched alkanes which tend to be less toxic and burn cleaner than aromatics, but reformation/dehydrogenation which produces aromatics is cheaper..

But yes, while the other aromatics aren't exactly healthy, they're nowhere as dangerous as benzene. So it makes sense to minimize the amount of benzene via regulation, but be a bit less strict about the other aromatics.

As an aside, a quick glance on that "fuelfreedom.org" site suggests they really like ethanol as a fuel additive, which makes me suspect they might be a front group for the corn ethanol lobby. So I'd be wary of taking what they say at face value.

Re: Benzene Exposure Alters Endocrine Activity

#143

Post by [deleted] »

AnotherGoodName wrote: post #126
zinclozenge wrote: post #60

When I was taking organic chemistry my (mid-to-late 60s at the time in ~20010) teacher told us an anecdote about benzene when we started learning about aromatic molecules. She told us that they used to clean their lab bench with benzene solvent to make it sparkling clean. Of course, she also told us it was carcinogenic and then finished by saying a lot of her contemporary colleagues that went into organic chemistry r…

It used to be the way to decaffeinate coffee https://www.landryswarr.com/did-you-know-decaf-coffee-used-t... In general if you drink decaffeinated coffee I'd check how it's decaffeinated. Even newer processes that use dichloromethane, ethyl acetate or triglycerides are dicey imho. The supercritical CO2 processes seem safe though. Truth be told I'd encourage anyone drinking decaf to really think about the benefits her…

[deleted]

Re: Benzene Exposure Alters Endocrine Activity

#144

Post by voxadam »

AnotherGoodName wrote: post #126
zinclozenge wrote: post #60

When I was taking organic chemistry my (mid-to-late 60s at the time in ~20010) teacher told us an anecdote about benzene when we started learning about aromatic molecules. She told us that they used to clean their lab bench with benzene solvent to make it sparkling clean. Of course, she also told us it was carcinogenic and then finished by saying a lot of her contemporary colleagues that went into organic chemistry r…

It used to be the way to decaffeinate coffee https://www.landryswarr.com/did-you-know-decaf-coffee-used-t... In general if you drink decaffeinated coffee I'd check how it's decaffeinated. Even newer processes that use dichloromethane, ethyl acetate or triglycerides are dicey imho. The supercritical CO2 processes seem safe though. Truth be told I'd encourage anyone drinking decaf to really think about the benefits her…

Wow. I knew decaffeination using dichloromethane (aka methylene chloride) was once a thing prior to the popularization of industrial scale supercritical CO2 but I had no idea benzene was ever employed.

Re: Benzene Exposure Alters Endocrine Activity

#145

Post by wil421 »

mint2 wrote: post #114
wil421 wrote: post #99

Earlier quoted context omitted.

A few guys I watch on YouTube repair cars with a mask on when they spray brake cleaner.

Note, the type of mask is pretty important. An n95 for particulates isn’t going to stop vapors nearly as well.

You can’t use n95 masks for toxic gases. These are what I would call paint respirators mask. It’s like a gas mask but doesn’t go over the face fully.

Re: Benzene Exposure Alters Endocrine Activity

#146

Post by hilbert42 »

zinclozenge wrote: post #60

When I was taking organic chemistry my (mid-to-late 60s at the time in ~20010) teacher told us an anecdote about benzene when we started learning about aromatic molecules. She told us that they used to clean their lab bench with benzene solvent to make it sparkling clean. Of course, she also told us it was carcinogenic and then finished by saying a lot of her contemporary colleagues that went into organic chemistry r…

"She told us that they used to clean their lab bench with benzene solvent to make it sparkling clean. Of course, she also told us it was carcinogenic and then finished by saying a lot of her contemporary"

That was about the same time I was learning the subject. We didn't get an anecdote about cleaning lab benches with benzene but were told it was very dangerous and carcinogenic.

Our teacher brought out a little bottle of the stuff—about 50ml or so—and told us that this was one aromatic hydrocarbon we weren't going to sniff and we should never attempt to do so. He also went on to stress that carbon tetrachloride was nearly as bad and said that none of the methyl chlorides could be 'trusted' as safe and with every extra Cl atom they became more toxic.

Advice I've always heeded. If this was common advice in lab science 50+ years ago then why is it even an issue today? All our chemical tech should have been built around this knowledge, the default should have been that benzene and humans should not mix—this paper ought to be a hypothetical as such exposure should not happen.

Incidentally, around that time there was controversy about removing carbon tetrachloride from dry cleaners, owners of these operations were complaining the new substitutes didn't remove grease as well.

Re: Benzene Exposure Alters Endocrine Activity

#147

Post by hilbert42 »

vondur wrote: post #89
zinclozenge wrote: post #60

When I was taking organic chemistry my (mid-to-late 60s at the time in ~20010) teacher told us an anecdote about benzene when we started learning about aromatic molecules. She told us that they used to clean their lab bench with benzene solvent to make it sparkling clean. Of course, she also told us it was carcinogenic and then finished by saying a lot of her contemporary colleagues that went into organic chemistry r…

Chemists used to basically bathe in Benzene back in the day. I’ve heard that they as a group tended to die in their 60’s. Most teaching Chem labs tend to work with small amounts of chemicals today and try to avoid the nasty stuff if possible.

"I’ve heard that they as a group tended to die in their 60’s."

Why then was my experience so different back then? We treated benzene and CCl4 with great care, a fume cupboard was esential. See my other post.

Re: Benzene Exposure Alters Endocrine Activity

#148

Post by hilbert42 »

hammock wrote: post #3

Benzene is everywhere, particularly in trace amounts in otherwise harmless products. Benzene is a building block for the production of many chemicals, including plastics, synthetic fibers, rubber, resins, dyes and pharmaceuticals, and residual amounts may remain in the final products. Benzene is used as a solvent and cleaning agent in printing, paint manufacturing, electronics, etc. Benzene contributes to the overall…

"Benzene is everywhere, ..."

The more I read these posts the more alarmed I become. As I posted above only minutes ago I was taught the dangers of benzene over 50 years ago to the extent that there were strict controls on how we used it—we weren't allowed to even take the stopper of the bottle unless it was in a fume cupboard.

Re: Benzene Exposure Alters Endocrine Activity

#149

Post by foo-bar-bat »

acumenical wrote: post #116
MisterTea wrote: post #102

Earlier quoted context omitted.

> it would be worse if I was a woman I'm sure, god knows what nonsense cosmetics contain They can always not apply them.

Yes, if they want to opt out of society. In most places outside the farm, for a woman not to apply makeup is career and social suicide.

Codswallop

Backwards thinking like your comment is a source of injustice, not a defense against it. What's your point... bad people impose values on others except when I do it too then I'm insightful?

Re: Benzene Exposure Alters Endocrine Activity

#150

Post by hilbert42 »

valianteffort wrote: post #137
tdeck wrote: post #135

Earlier quoted context omitted.

Speaking of bathing in benzene When I went to Belgium I visited the Red Star Line museum The Red Star Line was a passenger ship company that brought millions of immigrants from Europe to the US in the early 20th century. In order to depart for the US, passengers were required to scrub themswlves down with benzene and let it soak in to kill any potential lice eggs. Also their luggage was autoclaved (yep, with hot stea…

I believe around the same time the US was spraying migrants crossing the southern border with Zyklon B to deal with lice and typhus.

Benzene, C6H6 and Zyklon B (aka HCN) are very different chemicals and I'm not advocating HCN as a delousing agent. The difference is that the body copes with small amounts of HCN very well as small amounts can be naturally found in food whereas C6H6, an aromatic hydrocarbon, isn't. C6H6 does damage in an altogether different way and its effects are cumulative.

Incidentally, as I've mentioned in an earlier post I've always been very careful to avoid exposing myself to C6H6, but less so to HCN. I used to use HCN in photographic processing and as I mentioned once before on HN I was affected by its fumes—and I'm still here to mention the fact (but I'm not for a moment suggesting that people be lax when using the stuff).

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