Ask Carol – All About Disinfectants

Happy Monday, Friends! As promised – here is the next segment of the Ask Carol series.

JdM asked: “How do disinfectants destroy viruses?”

But first, a quote: ‘Bleach is one of the strongest anti-virals known to man, but don’t drink it.’– Carol’s virology professor, circa 1995.


DNA (deoxyribonucleic acid) and RNA (ribonucleic acid): AKA ‘genetic material’.  These are the blueprints for an organism.          

Organism: Life form – whether single-celled viruses or multi-cellular creatures like ourselves. Some argue that viruses are not technically alive – but they can infect other organisms to make copies of themselves – so let’s just call them living for the sake of this post, OK?         

Proteins: Genetic material is translated (transcribed) into proteins, which are one or more long chains of amino acids, and along with fats are the building blocks of every kind of cell.

Common Disinfectants:

Alcohol: This means ethyl alcohol or isopropyl alcohol, which have germicidal (germ-killing) properties. They work best in concentrations of 60%–90% alcohol in water (volume/volume). The germicidal activity drops sharply in concentrations of less than 50% – which is why you shouldn’t use whiskey or vodka as disinfectants. While alcohols destroy viruses, bacteria and many types of fungus, they do not destroy bacterial spores.

How it works: The most likely answer is that alcohol solutions of 60-90% denature (destroy) the structure of proteins. In single-celled organisms like bacteria and viruses, this is deadly because their outer protein coats become compromised, and other proteins important for their function become inactive.

Chlorides: The most common of these types of disinfectants is good old’ bleach (5.25-6.15% Sodium hypochlorite in water). Bleach, as you know, is corrosive to skin (and metal), but solutions of as little as 10% bleach in water are effective disinfectants and not as harsh.

How it works: The most accepted answer is the chlorine released from the bleach (as a free radical) oxidizes proteins, DNA, RNA in living organisms. Oxidation is any chemical reaction that involves the moving/loss of electrons and is damaging. Again, because bacteria and viruses are single-celled organisms, serious damage to their genetic material or outer coats is deadly.

Hydrogen peroxide: You know – the weird fizzy stuff you Mom used to slap on cuts.

How it works: The peroxide produces hydroxyl free radicals that attacks and destroys essential cell membranes, proteins and DNA – thus destroying the microbes

Phenolics: The most common phenol-containing disinfectant is Lysol, which contains 5-6% p-Chloro-o-benzylphenol (along with many other ingredients).

How it works: Lysol and other disinfectants like it work by inactivating essential proteins that are needed for function or for the integrity of cell walls.

Conclusions: So, there you have it. The common disinfectants we all know are not subtle operators. They are like bazookas to microbes (i.e. viruses and bacteria) and work by basically destroying the microbe’s genetic material (and ability to make more of itself) or by poking holes into its little virus/bacteria suit. However, while effective, these disinfectants act the same way on all cells, meaning when taken into your body they will harm your own cells as fast as they kill bacteria and viruses.

Want to read more?

Our friends at the CDC published the guide on disinfecting your home.

Someone close to me published this nifty review a few years ago.

Disclaimers required by my lawyers (Dewey, Cheatham & Howe): Isopropyl and methyl alcohol are extremely poisonous when taken into the human body by injecting or swallowing. And even though most hand sanitizers are made from ethyl alcohol (which is the stuff found in wine, beer and cocktails), please don’t drink that either as the other ingredients are gross-tasting and possibly toxic.

All household disinfect products are meant to clean surfaces and should be used as directed on their labels. They should never be injected or ingested – as they are very harmful and poisonous.

Stay safe and curious, Friends!

1 Comment

  1. Larry

    Someone close to you thanks you for linking his old review 🙂

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