Letters: Confusing public on chemistry

Wednesday August 14, 2019 Published in Letters to the Editor
Letters: Confusing public on chemistry

Dear editor,

I refer to an article in Cook Island News, Wednesday August 7, 2019 headed “Causing more harm than good” a most appropriate headline for other reasons than those aired in the article.

 

As an industrial chemist of 50 years I am constantly amazed by people with little understanding of chemistry who go into writing on a subject, that they are obviously passionate about, but either, through their lack of understanding of the subject or by inadvertent or deliberate misinformation, lead to confusing the reading public.

The author quotes from the Safety Data Sheets supplied by the manufacturer of 'Calcium Hypochlorite' which is the same dry powder chlorine many people use to disinfect their swimming pools with virtually no side effects.

The nasty safety aspects they list only apply to the concentrated dry powder.

In the swimming pool and the water supply the product is so dilute that none of these concerns apply.

To illustrate the point concentrated Hydrochloric acid is highly corrosive but when diluted is the acid produced in our stomachs to digest our food. The author erroneously refers to the product as 'chlorine' which it is not; however the disinfectant has the characteristic odour of chlorine.

In addition, whether or not it was a typographical error one of the product names refer to it as 'hydrochlorous acid '(which does not exist) the correct term is 'hypochlorous acid” and while this may appear as 'nit picking' the spelling of chemicals is very precise as the change of one letter can refer to an entirely different compound with properties ranging from benign to fatal. As an example, sulphite, sulphide and sulphate are all different compounds of sulphur.

Last but not least, the article goes on to acclaim 'Anolyte' as a safer method of disinfectant, however Anolyte is a brand name of the same, hypochlorous acid, produced in solution by a different means: but the sterilising agent is the same.

Without a doubt chlorination via hypochlorous acid is the cheapest most effective form of water pathogen treatment and has been used for close to 100 years around the world.

The majority of the negative hype is scaremongering to frighten the uneducated.

Rodney Fletcher

Nikao

1 comment

  • Comment Link Ian Calhaem Wednesday, 14 August 2019 17:43 posted by Ian Calhaem

    I must correct some of the statements made by Rodney Fletcher in his letter to the editor. When comparing different products it is very important to have all the facts. The Safety data sheet quoted by Papa Williams in his letter of the 7th August, is factually correct and defines the danger of Hypochlorite. If managed strictly according to the Code of Practice, then Hypochlorite can and has been used as a water disinfectant for many years. However, we live in a real world and mistakes can and do happen.
    In February this year, Pawawai School in Thames. New Zealand had the area cordoned off by the Fire Brigade whilst they decontaminated the area following a "Chlorine spillage". The caretaker had made the simple mistake of treating the school pool with acid and then forgetting to rinse out his bucket before adding calcium hypochlorite. The result was Chlorine gas, which is highly toxic. Eighteen people were taken to hospital for treatment.
    Papa Williams correctly pointed out that new technology is available - Electro-chemistry that removes the chance of such a mistake happening. He goes on to suggest that there should be open debate to learn about and understand what options for disinfection exist today, so that everyone can make informed decisions about how they want Cook Islands water to be disinfected.
    Anolyte is NOT a brand name - the particular form of Anolyte being talked about in the Cook Islands is Envirolyte - ANK Neutral Anolyte, which is a brand name and uses patented technology.
    Rodney Fletcher claims that chlorination which he attributes to Hypochlorous acid (and ignores the presence of hypochlorite ions) is the cheapest and most effective for of water disinfection. He is ignoring the fact that so many scientific papers and real world testing by research organisations have proven Anolyte to be 80-100 more effective that hypochlorite. He also ignores the fact that many cities worldwide are changing from Hypochlorite disinfection to Anolyte, giving the reasons as safety and cost.
    There are many technical reasons why the products are different, but perhaps the most convincing argument is a simple Comparison of the two products.
    If they were the same why is the Safety data sheet for ANK Neutral Anolyte so different to the Safety Data Sheet quoted by Papa Williams?
    At Maximum concentration (100%) ANK Neutral Anolyte is specified in the MSDS as:-
    Non-dangerous according to 88/279/EWG)
    In its strongest form MAY cause irritation to the eyes
    MAY cause slight irritation to open wounds
    MAY cause irritation to the throat and digestive tract if swallowed
    First Aid
    Flush with clean water
    Fire fighting measures
    None

    Clearly Anolyte is NOT the same as Hypochlorite.

    Another simple test is to compare the behaviour of the two products

    Comparison
    Hypochlorite (Chemical) Anolyte (Electro-Chemical)
    • Dangerous Good • 100% safe
    • Slow – needs 20 min contact time • Fast Acting (10-60 sec)
    • Leave toxic by-products • By-products salt and water
    • Special handling • No Special handling
    • Does not kill crypto & giardia • Kills crypto & giardia
    • Difficult to use • Simple to use

    Rodney Fletcher does not appear to understand why Electro-chemistry produces chemical reactions that are not obtainable from conventional chemistry. I do admit that this is a highly technical subject and the scientific papers are heavy reading. However, the physical properties speak for themselves, and in practice the important thing is to know that the process works and that it is much more effective that traditional disinfection methods. How it works is a "nice to know" for most users.

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