Letters: July 2019

Fluorine trouble

I responded the article ‘C–H fluoroalkylation tackles plastic waste’ (see p44) by tweeting: ‘This framing drives me crazy. It sounds like someone tackling the problem of plastic waste, right? But, no, it’s a group turning a persistent (non-fluorinated) material into an even more persistent fluorinated material.’

I am an environmental chemist who studies the environmental fates of both plastic materials and fluorinated compounds. We have chosen to work on both classes of materials in my group precisely because of their exceptional environmental persistence and their accompanying potential for environmental contamination. Converting conventional hydrocarbon plastic into hydrofluorocarbon plastic is certainly not tackling plastic waste, but in my view is a step in the wrong direction.

My doctorate involved organometallic chemistry and this gave me a deep appreciation for novel reactions and interesting approaches to otherwise difficult to prepare compounds. However, as someone who now studies environmental chemistry, I am deeply dismayed as I watch the growing wave of talented synthetic chemists being attracted to developing new routes to fluorinated organics. Indeed, we are already living through a crisis of polyfluoroalkyl substances (PFAS) contaminating groundwater throughout the US and other countries. What we need more than developing new ways to synthesise fluorinated organics is a deeper understanding of which fluorinated functional groups will not increase the persistence of the molecules we are making. If we cannot find such functional groups, then we should avoid mass-produced fluorinated organics altogether.

Kristopher McNeill FRSC
Zurich, Switzerland

Questioning methods

As a one-time forensic analyst in the drugs field at the Laboratory of the Government Chemist, I was flabbergasted to read that “There is a notable dearth of peer-reviewed, published studies establishing the scientific bases and validity of many forensic methods” (Chemistry World, June 2019, p12).

Almost invariably when giving evidence in a court of law I was questioned about my methodology by a defence or prosecution barrister. That the method I used (whether developed by myself, my colleagues or by another laboratory) had been published in a peer-reviewed scientific journal, often of international standing, generally satisfied the court that my conclusions were sound. If an expert witness is using unvalidated methodology, how does he/she answer this simple question?

Peter B Baker FRSC CChem
Great Missenden, UK

Clean chemistry

Plastic pollution is a problem of proportions approaching that of atmospheric pollution that is believed to be the cause of global warming; a problem full of uncertainties as suggested by Philip Robinson (Chemistry World, June 2019, p1). While measures to reduce emissions of carbon dioxide and methane are being introduced, there seems little that society can do to change public attitudes on the use and disposal of plastics. The bigger problem will be that of recovering the waste from the oceans and landfill. Cost will be the rate determining step, but it is my contention that once recovered most, if not all plastics can be degraded by UV and gamma radiation, treated chemically and recycled into materials used to generate clean energy.

Nuclear waste presents a similar problem. At a recent alumni visit to Leicester University I was most impressed by the development of americium-based thermocouple technology to power satellites; unwanted plutonium can be similarly useful. It has been said that plutonium contained in PCM (plutonium contaminated material) waste is too expensive to recover. ‘Costing’ is not my field but it seems to me that bacteria can be used to reduce its volume and existing chemistry can do the rest.

In the 20th century, chemists developed technological wonders; surely chemists now have a duty to clean up lab!

David Bradley FRSC
Liverpool, UK

Leading by example

I agree with Patrick Walter’s piece on laboratory safety (Chemistry World, May 2019, p6) in that those in charge should set an example.

Safety in laboratories depends ultimately on those working in them applying sound laboratory practice and the precautionary principle. In my experience, industrial laboratories tend to be safer than academic laboratories. 

The major hazard in industrial laboratories is managers who know no science. My candidate for the worst industrial laboratory was one where management had implemented a no tea or coffee break policy. Everyone was supposed to drink tea or coffee at their place of work, totally neglecting the fact that this should not be done in a laboratory.

The major hazard in university laboratories in my experience is PhD supervisors. The other hazard is PhD students. Some lack sound laboratory skills. Some lack any understanding of electrical earthing. Others lack both.

In my least favourite academic laboratory I can remember seeing a postgraduate student heating a five litre beaker of chloroform over a Bunsen burner in an open laboratory. The safety equipment in this laboratory consisted of one long thermal glove. I always wondered if it was originally part of a set of two. Perhaps the laboratory is haunted by the ghost of a chemist who lost an arm in a fatal explosion.

Bill Edwards FRSC CChem CSci
Braintree, UK

Your May 2019 issue discusses safety in the laboratory, repeating the conventional and well-meaning warnings. I would like to bring attention to a different view. Most institutions have safety rules which are enforced in a rigid manner. This fosters ignorance because rigid rules (about pipetting by mouth, for example) teach that water is just a dangerous as bromine. Are molecular biology laboratories subject to the same perils as laboratories that use butyl lithium? Ignorance is dangerous. One should know the properties of the substances and equipment that one works with. I have expanded on this in an article in J. Chem. Health Saf., 2018, 25, 41.

E. J. Behrman FRSC
Columbus, US