Subscribe to RSS





Recent Comments


Chemistry News

- 09/01/10 PHD comic: 'You autumn leave'
Piled Higher and Deeper RSS Gradfeed
- Fragrance Overload?
C&ENtral Science
- 2010 nobel predictions
Everyday Scientist
- EuCheMS - Colloids and culture
The Sceptical Chymist
- Nanopore-Based Screening
Chemical & Engineering News: Latest News
- Crew Reported Safe In Gulf Oil Platform Fire
Chemical & Engineering News: Latest News
- Stimulating quasi-erotic excitement through organic structure determination
The Curious Wavefunction
- Industrial Gas Companies Face Brazilian Fine Muito Grande
C&ENtral Science
- An Early Harvest of Biofuels News
C&ENtral Science
- Bacterial Altruism
Chemical & Engineering News: Latest News
- Orexigen Partners With Takeda for Potential Obesity Drug Contrave
C&ENtral Science
- Plagiarism: Is the Digital Age becoming its number one accomplice?
ASSETT
- Posters and Pickiness
In the Pipeline
- Cork rings: a collection of links
Chemjobber
- Chemjobber C&EN Index: August 23, 2010 issue
Chemjobber

The most recycled waste

by Crystallinity on Apr 24 2010 (7345 Views)

The most recycled waste is not glass, aluminum cans, plastic, or electronics, according to the EPA’s Municipal Solid Waste Report, last compiled with 2008 data, which I was referred to from a recent Scientific American article.   It is car batteries, almost all of which are recycled.  I actually have wondered what happens when they die, but I’m so glad to know that they ARE recycled.   Just a nice tidbit of knowledge for you there.   Recycling is more or less on the rise overall (see graph from the EPA report), thank goodness, despite the persistent folk out there who firmly believe that recycling has no net benefit and therefore don’t even try.

Recycling is obviously on the minds of environmentally-conscious chemists (and other people, I hear other people exist) – but when you think of recycling and trying to green up your daily work life, what do you think of?  Recyclable catalyst, acetone recycling, reading articles on your computer screen instead of on paper (including opting-out of C&EN’s print issues which, consequently, has decreased the degree to which I use it as a procrastination tool and the depth in which I read the non-science concentrates).  But what do YOU do?  I’m really curious to know.  Do you just shrug and carry on?

Guilt about the waste that we generate – and I can only attest to synthetic organic chemists and those who deal with tissue culture when it comes to the byproducts of science – is so, so heavy on my shoulders.  I’m not a crunchy tree-hugger (despite being a vegetarian, yes), but I AM uncomfortable with generating a crapload of waste in order to obtain a few pieces of paper – a couple JACS articles, a Ph.D., etc.  I know I’m not the only one that is frustrated to burn through so much physical material in the name of progress and intellectual/industrial pursuit.  But what else can you and I do, besides cut down on our chromatography, not use disposable items, recycle our acetone and keep all of our data and journals electronic?   How about big corporations?  Are they making efforts at sustainability so that they can claim they are, or to actually conserve resources?  Does it even matter?  Take for example the new SunChips bag released by Frito-Lay/PepsiCo, the first compostable chip bag ever.  It’s a start, no?

[I didn't mean for my first post to be so depressing!  It's an honor to be here and I hope to bring you more lively topics in the future.  Both the Chemistry Blog (naturally) and Chemical Crystallinity are on a list of top chemistry blogs for students; I don't know why this list was generated from the particular source it is hosted on, but it is pretty reasonable.]


Posted on : Apr 24 2010
Tags: , , , ,
Posted under opinion |

Chemical Journalism

by mitch on Feb 04 2010 (6811 Views)

For those with an interest in journalism and time this summer ACS is offering a summer internship in the C&EN newsroom. Deadline is Feb 22nd.

Chemical & Engineering News, the weekly newsmagazine of the American Chemical Society, seeks an intern for our Science/Technology/Education department for the summer of 2010.

C&EN reports current events in the chemical enterprise, including recent advances in research, education, industry, funding, and regulatory policy. C&EN reaches all 154,000 members of the ACS each week, and its online edition receives more than 13 million page views per year.

The candidate should be a highly motivated student or recent graduate with demonstrated interest in science writing and at least a bachelor’s degree in chemistry or a related field. The intern will have a chance to write bylined news and feature stories for publication in C&EN. We offer a $1500 monthly stipend for three months. The intern ideally will be based in our Washington, DC, headquarters; however, exceptional candidates unable to relocate may be considered. Starting and ending dates are flexible.

Contact Amanda Yarnell for more information about this year’s internship.

Link: C&EN Internships

Update: There is also an associate editor position available.

Mitch


Posted on : Feb 04 2010
Tags: ,
Posted under Uncategorized |

Condensed Print Format

by Phil on Jun 19 2009 (4230 Views)

My boss has pointed out this piece of news covered by C&EN. Apparently, starting from July, all ACS journals will be printed in a “rotated and condensed” format, that is two pages on one printed page in landscape format. This is an effort to reduce printing and distribution costs.

In my opinion, this change is just one further step towards purely electronic journals that are not printed at all. I think this will deeply affect the way we present our data and how we look at formatting. Preparing a manuscript in a way meant for printing is different from one which will never appear in print. Some may welcome this change because it saves paper, others will probably miss the possibility of flicking through a new issue of JACS. Although I rarely go to the library to pick up a printed journal, I admit to reading printouts very often (see this post).

Update: Apparently, in 2010 the print versions will stop completely, with the exception of JACS, Acc. Chem. Res. and Chem. Rev. See also Nature News.


Posted on : Jun 19 2009
Tags: , ,
Posted under opinion |

Chemistry Journalism

by mitch on May 12 2009 (1660 Views)
press hat

Recently, Chemical and Engineering News had to cut 16% of their staff due to decreasing ad revenue.[CS] Advertisers have been trending towards less spending, but this is often attributed to a lower subscription base. The number of C&EN’s subscribers do not fluctuate enough to account for this type of lost revenue, so what is causing the decrease?

After the layoffs there are now 48 C&EN’s staffers. If I assume the average salary is ~$5,000 per month, I have no clue if this is valid but it seems like a lower limit dollar value, then C&EN needs to make $240,000 per month to just cover payroll. Our dues pay for their paper, printing, and distribution costs. So let’s compare C&EN’s revenue model to Chemistry Blog. First we need to define some terms.

  • Uniques, defined as the number of unique people that read a website/magazine in a given week.
  • Revenue per unique per month. Average amount of revenue generated per unique reader in a month

With a weekly subscription volume of ~140,000, C&EN has a monthly unique volume of 560,000. Which means C&EN needs to make a minimum revenue per unique of $0.43 per month to cover my lower estimate of their payroll costs. On the other end of the spectrum, Chemistry Blog generated $15.00 in April from 20,000 uniques, this translates to ~$0.0008 of revenue per unique per month. The gist of this story is uniques are cheap online.

We at Chemistry Blog fully admit that C&EN is a better news source, better journalism, and a better target audience for advertisers. But from a purely marketing angle, Chemistry Blog is cheap at a cost of one fifth of one percent for what C&EN sells their uniques. I would guesstimate $0.10-$0.20 of revenue per unique per month is a more sustainable model that a huge niche journalism outlet like C&EN will be force to aim for in 10-20 years. Unfortunately, this means many more painful cuts in C&EN’s future.

Below are my suggestions to shore up C&EN balance sheets.

  • Expand to non-ACS web advertising: C&EN already has a relationship with advertisers, if they initiated an affiliate program where independent chemical websites get a share of what advertisers are willing to pay for adspace. This expands the audience they can tell advertisers will see their ads.
  • Many journalism outlets are scuttling their science sections. C&EN could sell their stories to these papers at a marked discount for what it costs to staff science journalists.
  • Participate more strongly in ACS membership drives, more members equals more subscriptions which will hopefully be proportional to more ad revenue.
  • Get a larger chunk of the budget subsidized from ACS.

None of these ideas are going to be the savior of chemical journalism, but it might ease the coming pain.

Mitch


Posted on : May 12 2009
Tags:
Posted under opinion |

The Name(ing) Game

by Jeremy on Mar 06 2009 (2223 Views)

legislationCheryl Hogue’s recent piece entitled “Naming What’s in Cleaning Products” caught my attention earlier this past weekend (C&EN, February 23, 2009).  Cheryl does a great job covering the interface of chemistry and the environment—hitting the high points while remaining concise—and the brief article in question is no exception.  However, the issue at hand was rather concerning.

In a nutshell, activists from an Oakland-based firm called EarthJustice recently filed a lawsuit in New York State demanding that several manufacturers/distributors disclose ingredients on the label of their household chemical products (detergents, cleaning agents, etc.).  Companies named in the lawsuit include Church & Dwight, Colgate-Palmolive, Procter & Gamble and Reckitt Benckiser.  The suit accuses manufacturers of failing to comply with a New York law that was enacted over 30 years ago.  The legislation at issue was passed in 1976 and makes two specific requirements.  First, the law essentially bans the presence of phosphates and nitrilotriacetic acid in household chemicals sold within New York State.  Second, the law requires household chemical manufacturers to stamp a list of ingredients onto the labels of their products.  From what I understand, this act was implemented to protect the overall environment of New York State (from urban areas to surrounding watersheds).  Ultimately, EarthJustice claims that forcing companies to comply with the law purportedly will increase public awareness, which, in turn, will help the environment

The lead attorney for EarthJustice, Keri Powell, made this argument to C&EN:

“People deserve to know whether the products they use to wash their dishes, launder their clothes, and clean their homes could be harmful.” 

I’m skeptical of this argument/lawsuit for a couple of reasons.  First, if this law has been dormant for the past 30 years, why is EarthJustice now pushing the issue?  Was New York State asleep at the wheel?  Isn’t this something that should’ve been handled by the EPA?  I realize environmental awareness is a hot topic and a popular vehicle for political action.  While the act of suing over labels to protect the environment is (in my mind) illogical, I am troubled over whether the issue is truly legitimate or a way for an unbiased organization to grind a political act (yes, I’m being cynical and possibly paranoid). 

Second, and more concerning, Ms. Powell (and her colleagues at EarthJustice) assumes that proper labeling will, in fact, increase public knowledge.  Her assumption is entirely conditional (certainly not sufficient) on whether or not a reasonable consumer would understand what they read.  Example: my mother is obsessed with the product Goof Off and has two cans of it on hand at any given time.  However, if Goof Off was labeled with its ingredients, she couldn’t tell you the first thing about xylene (the main chemical in Goof Off).  It took her strapping, young (and most definitely handsome) son to explain the potential risks of using such a product.

Don’t get me wrong.  My diverse background in hard science has taught me two very important lessons: learn as much as you possibly can and label everything.  Consumer chemical awareness requires the same conditions, and simply forcing a company to slap a label on something doesn’t solve the problem.  In my mind, the issue of chemical awareness is similar to the “ban dihyrogen monoxide” prank conducted a few years back.  Without education (i.e. learning what the chemicals names actually mean), this proposed labeling crusade is largely irrelevant. 

Furthermore, chemical information is readily available (assuming you or your public library has access to the internet).  While there are a few exceptions, every chemical product (including those used at home) must have an MSDS, which can be found online.  Every MSDS identifies the chief ingredients in said product.  Granted, MSDS’s were created for the purposes of right-to-know information in industrial/commercial settings.  But, in my opinion, if John Q. Consumer can read a label, he can certainly read an MSDS.

I salute EarthJustice for all the work they’ve done to protect America’s environment.  Their commitment to public interest is genuine and deserves applause.  However, I think they are barking up the wrong tree with this lawsuit—dragging a whole bunch of companies through expensive court process to get something to happen that’s relevance is moot (at best).  My solution?  Shift the focus.  For example, serve the public’s interest by teaching them how to access/read/interpret chemical information.  Or educate the public on how phosphates are detrimental to the environment.  Lobby politicians to entirely ban certain household chemicals in the state (beyond the ppm limits currently set). 

Let’s assume EarthJustice wins the lawsuit.  What happens next?  Maybe it’s me, but I don’t see an end game in sight.  

P.S. In addition to C&ENews, this story has been picked up by Scientific American, the New York Times and the Los Angeles Times.


Hot news on an old story

by Phil on Feb 13 2009 (2652 Views)

Some stories never seem to end. The hexacyclinol story is one of them. Is it over now?

I assume most readers will be familiar with the controversy about the two proposed structures of hexacyclinol, the original one (1) and a revised one (2), and about a total synthesis of 1 by James LaClair that was challenged by Rychnovsky and Porco on the basis of calculations and a synthesis of 2. The debate has been extensively covered in the blogosphere, e.g. in C&EN and by Derek Lowe.

Proposed structures of hexacyclinol

Proposed structures of hexacyclinol

There is some new evidence now. An Italian group have simulated the 1H and 13C NMR spectra of both structures using DFT calculations (Org. Lett. ASAP). The calculated spectra seem to point to 2 as the correct structure. In addition, 1 cannot have the same spectra as 2 according to the calculations. The authors summarize: “The structure of hexacyclinol is confirmed to be 2. Furthermore, if 1 had been synthesized or was formed from an unforeseen reaction, its NMR spectra are sufficiently different from those of 2 as to guarantee their distinction.” This seems to exclude LaClair’s claim that structure 1, which is the target of his total synthesis, happens to have the same spectral data as 2. The authors of the paper are of course reluctant to draw the obvious conclusion.

Update: This piece of news has been covered in Derek Lowe’s blog. There has been quite a discussion, with James LaClair participating in person! It has also appeared in The Chem Blog.


tert-Butyllithium Claims Fellow Chemist at UCLA

by mitch on Jan 20 2009 (42786 Views)
butyllithium

Story is from UCLA Newsroom (Jan 19th):

A UCLA research assistant who was seriously burned in a laboratory fire last month has died of her injuries.

The 22-year-old woman, whose name has not been released, died on Jan. 16 at Grossman Burn Center in Sherman Oaks. She was transferred there after initial treatment for second- and third-degree burns at Ronald Reagan UCLA Medical Center.

The accident occurred Dec. 29 while the assistant was working with T-Butyl lithium, a highly flammable compound, in UCLA’s Molecular Sciences Building. The fire was extinguished by a colleague.

The fire is under investigation by UCLA’s Environment, Health and Safety department.

Link to article: Research assistant dies of injuries suffered in December lab fire

Update 1: More experimental details are coming out.

A 23 year old female research associate/laboratory technician intended to add an (unknown) aliquot of 1.6 M t-bu-Li (in pentane) to a round bottom flask, placed in a dry ice/acetone bath. She had been employed in the lab for about 3 months. The incident occurred on Dec. 29, during the UCLA holiday shutdown between Christmas and New Years. Researchers are granted permission to work during the shut down for “critical research needs.” There were two post doctoral researchers working in the lab and the adjacent lab, with limited English proficiency.

The principal investigator had trained the employee to slightly pressurize the bottle (an ~ 250 ml Aldrich Sure Seal container) with Argon and withdraw the desired aliquot using a 60 ml syringe, fitted with a 20 gauge needle. The PI likes to use these particular syringes because they have a tight seal. There is no evidence that the employee used this method. Speculation: she may have just tried to pull up the aliquot in the syringe. Somehow, the syringe plunger popped out or was pulled out of the syringe barrel, splashing the employee with t-bu-Li and pentane. The mixture caught fire, upon contact with air. She was wearing nitrile gloves, safety glasses and synthetic sweater. She was not wearing a lab coat. The fire ignited the gloves and the sweater.

Six feet from the fume hood was an emergency shower. When the employee’s gloves and clothing caught fire, she ran from the area away from the shower. One of the post-docs used his lab coat to smother the flames. 911 was called. UCLA Fire Dept. and emergency medical, Los Angeles City Fire, and Los Angeles County Haz Mat. The EMTs put the employee in the safety shower for gross decon and then transported her to the ER. She’s currently in the Grossman burn unit in Sherman Oaks with second degree burns on her arms and third degree burns on her hands, a total of about 40% of her body. There was very little damage to the lab. Bill has not interviewed the employee.

From: http://list.uvm.edu/cgi-bin/wa?A2=ind0901&L=DCHAS-L&P=13210

Update 2: From Daily Bruin (Jan 14th): Lab safety to be revised

Update 3: For those interested, the Chemistry Reddit is also tracking this story: A death in the science family. Be carefull with tert-butyl lithium!

Update 4: Proper Aldrich Sure-Seal technique can be found here: Handling air-sensitive reagents

Update 5: Name has been released from the Daily Bruin (Jan 21st): Assistant dies of fire injuries.

Update 6: Jyllian Kemsley from C&EN has picked up the story (Jan 22nd): Researcher Dies After Lab Fire

Update 7: Sheri Sangji facebook memorial for friends and family (Jan 22nd):
http://www.facebook.com/group.php?gid=116158190606

Update 8: Derek Lowe reminiscing on fires with tertiary butyllithium (Mar 2007): How Not to Do It

Update 9: Rebecca Trager also covering the story for RSC’s Chemistry World (Jan 23rd): UCLA lab assistant dies

Update 10: Derek Lowe mentions new fatality from trimethylsilyl diazomethane (Jan 23rd): The Real Hazards of the Lab

Update 11: Critiques of lab safety in Academia: Lab safety and chemical hygene in acadamia blows[TCB], A Death in the Lab[MCC]

Update 12: I was cleaning up some of the rabble-debate whether to release the PI name and accidentally deleted more comments then was my intention. Apologies to all commenteers effected. (Feb 19th)

Update 13: C&EN releases PI name. Insights: Learning From Mistakes (Subscription needed, Feb. 23rd)

Update 14: Los Angeles Times investigatory story on the accident. Deadly UCLA lab fire leaves haunting questions (Mar 1st)

Update 15: ChemJobber: What happened to Sheri Sangji? (Feb 27)

Update 16: LA Times: New details emerge in fatal UCLA lab fire (Apr 29)

Update 17: LA Times: State fines UCLA in fatal lab fire Fined $31,875 and Cal/OSHA will prepare an additional report to present to the Los Angeles County district attorney for consideration of criminal prosecution. (May 5th)

Update 18: ChemJobber: Patrick Harran, peeing in the jury pool? (May 5th)

Update 19: Statement of Patrick Harran

My students and I deeply mourn the death of our friend Sheri Sangji, and we realize our pain cannot possibly compare with the anguish felt by her family. She was an exceptionally gifted young woman with a bright future ahead, and her loss is truly tragic.

Since Sheri’s death, attention has focused on inspection and training records. These protocols are very important in developing and documenting a culture of safety, but in this case they are largely unrelated to the accident of Dec. 29, 2008. Sheri was an experienced chemist and published researcher who exuded confidence and had performed this experiment before in my lab. Sheri had previous experience handling pyrophorics, chemicals that burn upon exposure to air, even before she arrived at UCLA. Her most recent position prior to joining the group involved “scale-up process safety.” However, it seems evident, based on mistakes investigators tell us were made that day, I underestimated her understanding of the care necessary when working with such materials.

Sheri’s death resulted from a tragic accident. The California Division of Occupational Safety and Health has found no willful violations in its report. Throughout my career, I have strived to create a culture of safety. I am haunted by memories of this tragedy and wish that nothing like it happens again – in my lab or any other. In continuing our research, I go forward with a heavy heart in remembrance of Sheri and with a rededication to safety. I will also work tirelessly to achieve Chancellor Block’s goal of making UCLA the leader in safe laboratory practices.

(May ~5th)

Update 20: Chemical and Engineering News: UCLA Fined In Researcher’s Death (May 5th)

Update 21: Chemical and Engineering News: Negligence Caused UCLA Death (May 7th)

Update 22: Harry Elston’s Recipe for disaster editorial in the Journal of Chemical Health and Safety 2009, 16 (3), 3. (DOI: 10.1016/j.jchas.2009.03.011) (March 29th 2009)

Update 23: Science: Taken for Granted: The Burning Question of Laboratory Safety (May 1st 2009)

Update 24: ChemJobber: If I were working with tert-butyllithium… (May 10th 2009)

Update 25: The Sheri Sangji Petition: A tragic & preventable death (May 12th 2009)

Update 26: The California Fatality Assessment and Control Evaluation (CA/FACE): Worker Fatality Alert (May ~14th 2009)

Update 27: A Tribute to Sheri Sangji: www.sherisangji.com (May ~15th 2009)

Update 28: C&EN: UCLA Appeals Citations by Jyllian Kemsley (June 17th 2009)

Update 29: LA Times: Family of UCLA lab fire victim criticizes investigation (June 22nd 2009)

Update 30: LA Times: Cal/OSHA chief to oversee criminal investigation of fatal UCLA lab fire (June 30th 2009)

Update 32: An intensely detailed account of the experiment that caused Sangji her life. C&EN — Learning From UCLA (August 3rd 2009)

Update 33: ChemJobber and Chemical Space

Update 34: C&ENtral Science — Evaluating Safety (August 3rd 2009)

Update 35: C&ENtral Science — Personal Protection from Fire (August 4th 2009)

Update 36: C&ENtral Science reports their timeline of the accident and allegations of tampering — Tampering with Evidence? (August 5th 2009)

  • The fire occurred shortly before 3 PM on Dec. 29, 2008. Sheharbano (Sheri) Sangji was taken to the emergency room and Harran followed.
  • After Sangji and Harran left, Los Angeles County hazardous materials crews cleaned up the lab. (Recall that medical personnel had put Sangji under the safety shower. Showers are supposed to run at a minimum of 75.7 L/minute for 15 minutes, so there should have been about 1,100 L of water to test and mop up.)
  • Harran returned to the lab around 7 PM and was asked by fire officials to shut down the experiment to ensure the hood was safe.
  • Sometime after Harran shut down the experiment, UCLA deputy fire marshal Christopher Lutton took photographs of the lab and Sangji’s hood. Lutton also told Harran that the lab would be locked and investigated, although there’s no record of exactly what Lutton said.
  • At around 7:30 PM, Lutton left the lab and went down to his vehicle remove his gear, call the locksmith, and call one of his colleagues.
  • At about 8:30 PM, Lutton returned to the lab to find Harran and postdocs Weifeng Chen and Hui Ding in the lab. In a later interview with Gene Gorostiza, the UCLA police detective who investigated the scene tampering allegations, Ding said that he and Chen removed six empty flammable liquids containers from the lab and put them in the building’s trash. They also put other solvent containers into a lab storage cabinet.
  • Lutton ordered everyone out of the room and stayed on the scene until the locksmith arrived at 9:55 PM.
  • The locksmith finished changing the locks at 11:35 PM. At that point, the doors were locked and Lutton took possession of the only key, put up yellow barrier tape, and left.
  • Lutton returned to the lab the next morning to find that the restraining bolts in a side panel to one of the doors had been released, allowing the door to open freely. Lutton told Gorostiza that at that point he discovered that the room contents had been tampered with. A timeline of the incident included in UCLA fire marshal documents says that, comparing photos of the lab taken in the morning to the ones taken the previous evening, containers of flammable liquids were removed, other containers were moved into a walk-in fume hood, a cabinet door was left ajar, and some items in the fume hood where the fire had occurred had been moved around.

Update 37: C&ENtral Science — Promoting Safe Research Practices (August 6th 2009)

Update 38: C&ENtral Science — Some Thoughts on Lab Incidents (August 7th 2009)

Mitch (Our best thoughts, from everyone at Chemistry Blog, go to her family at this time)


Paul Bracher from ChemBark is back.

by mitch on Jan 18 2009 (1920 Views)

Paul Bracher from ChemBark fame is currently blogging for C&EN Blog in case you missed it.

chembark2

Link: Proper Usage Of PTNs

Mitch


Posted on : Jan 18 2009
Tags: , ,
Posted under Uncategorized |

Anti-Freeze and the Automotive Industry

by Jeremy on Dec 28 2008 (3669 Views)

My brother-in-law recently bought a new car with the intention of taking it with him into the Rocky Mountains in a few years.  Worried about sub-zero temperatures, he looked into modifying his coolant/anti-freeze system and learned about a new trend in the automotive industry.  An increasing number of suppliers have begun marketing propylene glycol as an alternative to the widely used ethylene glycol because propylene glycol has a lower freezing point than its two-carbon sibling.  A savvy chemist should instinctively think “freezing-point-depression,” a staple of freshman general chemistry lectures.  Mathematically, it’s identified by the following equation:

1

Wikipedia will inform you that freezing-point depression is a relation of the Clausius-Clapeyron equation and Raoult’s law.  Personally, I have not found use for either of these equations, and I’m not about to BS my way through the derivatives (pchem was not my strong point as an undergrad).  Anyhow, the above equation tells us that a pure compound’s freezing point will drop if you add another solvent to the solution.  For example, water typically freezes at 0 oC and propylene glycol freezes at 59 oC.  According to Sierra Anti-Freeze’s literature, a 2/3 mixture (by volume) of propylene glycol and water will start to crystallize at -4 oC, whereas a 3/2 mixture will begin crystallization at -54 oC.  In fact, the change in water’s freezing point is much larger with propylene glycol than with ethylene glycol. 

2Ethylene glycol is an interesting compound.  The majority of households know that anti-freeze (i.e. ethylene glycol) is highly toxic and that dogs like to drink it.  Upon ingestion mammals digest ethylene glycol by oxidizing it to oxalic acid (among other compounds), which has been linked to kidney failure.  Ethylene glycol purportedly tastes sweet to humans and dogs, which has prompted manufactuers to begin adding a bittering agent.  C&EN covered the issue a couple years back and from what I’ve recently read only Maine, Arizona, New Mexico, California and Oregon require bittering additives by law; Wisconsin’s right behind them.  For whatever it’s worth, the bittering agent (denatonium benzoate) is sold commercially as Bitrex or Aversion and is added to products such as rat poisons to prevent human consumption.  By comparison, propylene glycol is generally regarded as a safe, non-toxic chemical.

If propylene glycol is safer and appears more advantageous than ethylene glycol, why does the auto industry use it?  I couldn’t find an answer.  I did learn that some automobile manufacturers will actually void your warranty if you do not use their “approved” anti-freeze (usually ethylene glycol). Perhaps this issue will be addressed by the Obama-appointed US car czar in January. 
 


Posted on : Dec 28 2008
Tags: ,
Posted under general chemistry |



Google Ads





Recent Chemistry

1H NMR Relaxometry Study of a Rod-Like Chiral Liquid Crystal in Its Isotropic, Cholesteric, TGBA*, and TGBC* Phases
(The Journal of Physical Chemistry B)
ChemFeeds Nav: [Leave a Comment][See Related]

Good Chemistry Books


Computational Medicinal Chemistry for Drug Discovery

Free Energy Calculations in Rational Drug Design


Social Chemistry

- Probably the best chemistry channel on YouTube. [54 minutes ago]
Chemistry Reddit
- An Urgent Question [7 hours ago]
Chemical Forums - Materials Chemistry
- I can't wrap my head around s and p orbitals! [11 hours ago]
Chemistry Reddit
- Free radical reaction of carbon or silicon to aluminum [12 hours ago]
Chemical Forums - Analytical (Undergraduate)
- Primo Levi - Periodic Table of Videos [17 hours ago]
Chemistry Reddit
- Allylic alcohol, configuration inversion. [17 hours ago]
Chemical Forums - Organic (Undergraduate)
- Could a good chemist weigh in on a question I'd like to be more informed about; Is sous-vide cooking safe? [18 hours ago]
Chemistry Reddit
- What is the most dangerous substance according the NFPA 704 System? [19 hours ago]
Chemistry Reddit
- Solubility Software - Salting Out [20 hours ago]
Chemical Forums - Analytical (Undergraduate)
- File Format Conversion from GCMS raw data to .CDF format [22 hours ago]
Chemical Forums - Analytical (Undergraduate)
- transport number [1 day ago]
Chemical Forums - Physical (Graduate)
- Dear Chemit, I have a college Chemistry 102 proficiency exam tomorrow. What should I know? [1 day ago]
Chemistry Reddit