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Villian of the week: asbestos

25 July 2012 - Be scared

It is summer time, everybody is on vacation or so it seems (this is Europe) and if it wasn't for sports the media would have nothing to report. Last year's media-aggrevated event was the the case of the contaminated cucumbers in Germany (source never found) and the year before that a big cat was on the loose in the Dutch countryside (also never found). This years hype is possibly an asbestos scare in the city of Utrecht.
Over a 100 residents of a group of apartment buildings were told by the police on Sunday they could not return to their homes because the place was contaminated by asbestos as a result of renovation work. This raised a lot of eyebrows: the renovation work had already started earlier in the week and the asbestos they knew was there was handled by a specialised company. Also curious: the reports to date fail to identify the type of asbestos involved and according to city officials and the owner of the building the analysis results will take up to week to arrive.
The technicians on the scene (see pic here) are busy with air sampling devices so it is also an airborne threat under investigation. According to this report from the U.S. Environmental Protection Agency (2004) phase contrast microscopy or TEM are the weapons of choice for actually counting the number of asbestos particles in samples. But why would this take so long?

In this news report a representative of the building society explains that as many labs as possible were contracted for the analysis work. A total of 6500 samples, 33 per apartment according to another source. The results were already in but analysing exactly what was going on would require more time. If nothing was found you can return to the contaminate site and filter air samples for a much longer time in order to get a significant result. When the results from the various laboratories contradict each other of course you also have a problem.
Simon Roozendaal of Elsevier was quick to comment the government should not scare the public. Asbestos is a serious occupational hazard but you have nothing to fear from a single exposure. Twitter is equally sceptic: smoking is a larger health risk. And has anyone already mentioned the neighbourhood is wedged in between 2 of the countries busiest highways?

Update 26-07: Asbestos specialist estimates risk illness 1 in 1.7 billion (VK)
Update 26-07: building society has already spent over 1 million euros(VK)
Update 27-07: the culprit is so-called spuitasbest (nu.nl). Mostly amosite, highly concentrated but not coagulated and therefore more dangerous than other asbestos types(infomil.nl)
Update 27-07: Another specialist has doubts about the spuitasbest story. Used to processed exclusively in industry for treatment of large metal surfaces like those on ships but not in housing! (nos.nl)
Update 27-07: Next specialist: spuitasbest has consistency of pur foam and cannot contaminate a site like this. Contamination of a house is not possible from the outside to the inside because a house is always overpressurised. (nrc.nl). Does this make sense from a physics perspective?
Update 02-08: It is getting worse: police force 42 people out of their homes in Rotterdam in new asbestos scare (nrc.nl)
Update 02-08: And worse. Another evacuation now in Emmeloord (nos.nl)
Update 02-08:In the meanwhile the Utrecht residents can return home: no asbestos was found... (nos.nl)
Update 02-08: Twitter complaints. In the Netherlands four million homes have been built in the 1970's and 1980's possibly containing asbestos. Will Germany be able to handle that many refugees? or will the authorities come to their senses?
Update 16-08: Forgot to mention, another 2011 non-event in the Dutch media was the highway shooter and of course never found. Another 2012 event is the Rijkswaterstaat shaking building. Cause unknown.
Update 16-08:The report is in!

Target: Dow Chemical Terneuzen

20 July 2012 - The Law

120px Inhallation Hazard.jpgIn a previous episode here we have seen how Chemie-Pack senior management was hauled into prison for blatant disrespect of Dutch safety- and regulatory laws. This time the management of Dow Chemical location Terneuzen has to worry. The company will be prosecuted for a series of offences (Link) that took place between 2005 and 2008. Examples are the release of a large amount of naphtha gas (Link) and a release of 2000 liters of benzene. According to the prosecution office Dow Chemical puts production before maintenance and personnel safety. On several occasions the company did not bother to report the incidents to the local authorities.

In related news in the Netherlands half the companies working with hazardous materials violate safety regulations (link). Agencies responsible for monitoring the chemical industry have pledged to take their work more seriously: less paperwork and more actual physical presence at the plants (link). According to the provinces already more visitations take place and more companies get fined (link). Example at hand: today an oil terminal in Rotterdam owned by Odfjell was shut down on suspicion of poorly maintained fire fighting equipment. (Link). According the local environmental government agency this facility too, like Dow Chemical, has a long history of neglecting the rules.

It is all too clear that in the aftermath of Chemie-Pack the Dutch government has toughened up its image. With violators prosecution is certain. Jail time for management is an option. The Chemie-Pack trial starts in October (Link)

Target: Cetirizine

06 July 2012 - The Free Chemical Abstract Service

cetirizine synthesis Reiter 2012  Target: Cetirizine
Authors:Reiter, Trinka, Bartha ,Pongo, Volk, Simig
Publication: DOI
Synthetic scale: 50 - 150 Kg
Step 1: 4-chlorobenzophenone organic reduction (sodium borohydride), methyltrioctylammonium chloride phase-transfer catalyst (toluene/water)
Step 2: thionyl chloride chlorination (toluene)
Step 3: N-(2-hydroxyethyl)piperazine amine alkylation (toluene)
Step 4: free amine liberation NaOH water/ toluene
Step 5: 2-chloro-N,Ndimethylacetamide O-alkylation (toluene), HCl workup
Step 6: Amide hydrolysis, NaOH / water
Features: patent noninfringing, single solvent system toluene/water.

Higgs in the media

04 July 2012 - Physics

NOS Higgs announcement.gifCERN today announced they have successfully detected the Higgs boson. Congratulations! Particle physics is a tremendously difficult to understand science and it is interesting to see how the news is presented in the media. Dutch television news is dominated by tax-payer financed NOS News (50 million euro budget) and commercial RTL Nieuws (25 million budget).
A RTL newsman correctly stated that the Higgs particle is so important because it gives everything its mass and not only to this brick (man is holding a brick in his hands). His colleague incorrectly stated that the Higgs particle is coming from outer space and therefore also known as the "God particle" .
The NOS news people were also preoccupied with a brick. Their item (with animation) starts with the assertion that everything consists of elementary particles. The animation against a backdrop of planet Earth shows a dog, a tree, then the Dutch prime-minister (?), then a (subliminally connected) banana and then a brick! What happens next is confusing. The animation shows a brick, a magnifier and an atom, right? The voice-over however states that that if you could really zoom in you would see it is composed of really tiny particles, the quarks and electrons. This does not make sense. As a minor offence the voice-over repeatedly feels the need to translate mass as weight. Otherwise the viewers will not understand?
The animation should have stressed that the research was aimed beyond molecules and atoms at the properties of subatomic particles like protons and electrons. They could have drawn inspiration from the classic 1977 Powers of Ten.

Two views on anti-Markovnikov Wacker oxidation

01 July 2012 - Catalysis

Wacker oxidation Teo grubbs 2012  Chemistry can be a slow-paced science when it comes to sorting out specific problems. Take for example the anti-Markovnikov Wacker-Tsuji oxidation of styrene. Peilli Teo of the grubbs lab has just published (DOI) a novel variation to a procedure first established in 1986 by Ben Feringa (DOI).
In a regular Wacker oxidation an alkene is oxidized to a ketone with a palladium(II) catalyst in presence of water. Pd is continuously regenerated by copper chloride which is in itself regenerated by oxygen so the reaction is potentially cheap to run as none of the metals is actually consumed. The addition however is Markovnikov because somewhere a carbocation must be accommodated and hence the ketone is formed. So how to get to the aldehyde instead?

Feringa in 1986 only had to replace one chlorine ligand by a nitro ligand in the catalyst and replace solvent DMF by tert-butanol to make it all happen. As often happens in chemical research this finding was entirely "unexpectedly". We have to admire Feringa's sense of creative accounting. The yield is appalling (just 9%) so the main table only has the yields listed in mmoles (you have to do the math yourself). One claim mentioned in the text itself reports a fantastic 280% yield but that one is measured against palladium of course.
So how has the Grubbs team improved on this procedure? Copper and oxygen have been replaced by stoichiometric p-benzoquinone, the original Pd catalyst is restored and very smartly: they added water. The isolated yield jumps to 83% and the team notes that although adding water is not strictly needed (tBuOH is wet enough) without it, the yield drops again to 38%. Feringa reported adding water did nothing.
Mechanistically there is not a lot of agreement either. Feringa has a prominent role for the nitro ligand to play. The PdNO pentacycle falls apart in the beta-elimination. In the Grubbs model the first intermediate is the tert-buyl vinyl ether which is then hydrolysed. Considering the steric bulk involved only the Grubbs model makes sense.