Your views on terminology, SI units and antifouling paint

Word search

With regard to the editor comment on the letter published about use of the word ‘radioisotope’ in the last issue (Chemistry World, January 2019, p4) I was dismayed to see that the writers point was considered etymological.

The writer was clearly stating that regardless of the root of the word it was being used to describe something incorrectly.

While the evolution of everyday language is fascinating and perhaps even to be encouraged scientific terms have precise meanings that relate to a specific thing and cannot and should not be interchanged. The atom may now be recognised as being divisible but we all know what an atom is and it allows us to communicate effectively as scientists.

The misuse of technical terms with specific meanings is in no way etymology and I would expect the Royal Society of Chemistry to understand that.

Gayle Cairns CChem, CSci, MRSC
Gloucester, UK


Making me SI

There are several problems with the new SI units (Chemistry World, January 2019, p9). The first is that it is based on the assumption that the fundamental physical constants are universally constant. We do not know this. Indeed, some cosmologists speculate that the speed of light in a vacuum may vary under certain conditions.

A second problem is that it complicates the teaching of mass. Mass is a basic physical quantity. It comes at the beginning of a course in science. Linking the kilogram to the Planck constant brings in the quantum theory. This complication could have been avoided if the kilogram had been redefined as the mass of a fixed number of silicon-28 atoms.

A third problem is that fixing the value of the Avogadro constant affects the molar mass constant (the constant that converts relative atomic and molecular masses to molar masses in g mol‒1). On the old system this took an exact value (MƟ = 1g mol‒1); on the new system it has to be experimentally determined.

Peter Nelson MRSC
University of Hull, UK


Seems to me that there is no major difference between the new and old definition of the mole. The new definition is just some arbitrary number, while the old definition relates to something tangible.

Franz Wimmer, via website


Out with a Bangor

Editor: In January, we reported the closure of the chemistry department at the University of Bangor, north Wales (see p9). The news was not well received…

How much would you wager that the university will continue offering soft sociological or even pseudoscientific subjects? What kind of educational system is so enfeebled that it cannot even produce a quorum of students interested enough in real knowledge to sustain a core curriculum? Rhag cywilydd!

John, via website


This is unsurprising. Other universities have been cutting chemistry courses – or even whole departments – for years. Like most practical science, technology, engineering and mathematics courses it costs a lot more than the [student] fees to run, and given the very limited student base (‘currently the only one that can be partly taken in Welsh’) it’s hard to see any way to recruit more students.

Neil, via website


As a studying chemist, I would argue the requirements are too rigorous and unnecessary [to enter at degree level]. Requiring maths courses makes our field unattractive and intimidating. Business has ‘business maths’ – we need a ‘chemistry maths’. Chemistry is cool and the shut down of the department is depressing news.

Khayyam, via website

No harm, no foul

Editor: We also reported on the move away by AkzoNobel and others from copper-bottomed ships and the role of antifouling paint (p18), which sparked this response.

Although main task is to remove fouling organisms from the ships’ hull, special care should be taken for fouling organisms. The fouling process is a ‘natural’ process – therefore, the anti-fouling processes should be natural. Have you ever seen a shark whom emits UV light to remove fouling organisms from its skin? We should mimic the nature, I believe. Although I do not have the detail of the work of AkzoNobel, I know that UV light can be very dangerous for fouling organisms. The green formulas should be prioritised in R&D studies. We are still remarkably far from the amazing chemistry of marine organisms when it comes to antifouling strategies, who have based their methods on millions of years’ experience in the field.

The consumers of the antifouling paints should know that 70 million tons of copper-based biocides, 6 million tons of booster biocides, and 20 million litres of solvent are released into oceans and also atmosphere per year, respectively. This is not a sustainable process, and I am not happy with the releasing very stable compounds such as copper and zinc in the oceans. Readers should also know that the development of a new antifouling agents are so costly. I found the estimated costs regarding development of an antifouling agents from published papers are as follows: toxicity studies on active substances, €1–3 million (£0.8–2.6 million); environmental studies and ecotoxicity €0.6–4 million; formulation studies €1 million; risk assessments and exposure scenario expertise €1 million; plus costs such as dossier preparation, registration fees and task forces.

Levent, via website