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Q: Does sanitiser have to contain alcohol? May 12, 2020

 

 

0% ALCOHOL LABEL

 

Q: Does sanitiser need to be alcohol-based?

A: No. It depends on the active ingredient.  

The active agent in the sanitiser you use should be suited to the specific situation and the objective of the sanitation.

The purpose of this article is to delve into the positives and negatives of both alcohol-based and alcohol-free sanitisers, and help answer your questions; ‘Does my sanitiser need to be alcohol-based?’ and ‘Which sanitiser should I use?’

 

What are the different types of sanitisers?

 

The most common sanitisers are :

  • Sodium Hypochlorite (NaCIO – Commonly known as Chlorine or bleach)
  • Ethanol or Isopropanol alcohol-based sanitisers
  • Quaternary Ammonium Compounds (QAC’s), which are becoming more widely used in place of Sodium Hypochlorite due to its toxicity. 
  • Hypochlorous Acid (HOCl) is a non-toxic sanitising agent that has been experimented with for many years.  It is now approved and recognised in most countries as an effective sanitiser and disinfectant.

 

Let’s compare the different types …

 

Sodium Hypochlorite | NaCIO

This chlorine compound works by denaturing the proteins in practically any micro-organism through a process called oxidation. It is a highly effective sanitiser and disinfectant.

Sodium Hypochlorite is composed of Sodium (Na), Chlorine (CI), and Oxygen (O). Its structure involves the ionic bond between hypochlorite ion (CIO-) and Sodium ion (Na+), producing the neutrally charged NaCIO.

Sodium Hypochlorite Chemical Structure
Sodium Hypochlorite Chemical Structure.

Positives:

  • Highly effective against all main pathogens (Bacteria, Viruses, Spores, Fungi and Biofilm).
  • Ability to disinfect and sterilise.

Negatives:

  • Very toxic
  • Affected by organic soil

 

 

Alcohol-based sanitisers | Ethanol & Isopropanol

Both alcohols work by penetrating the cell wall of micro-organisms, denaturing proteins and dissolving lipids. Ethanol has been proven to be more effective against viricidal activity, and Isopropyl has is shown to be more efficacy against bacterial activity. Both are ineffective against spores.

Ethanol (C2H6O) is the most common alcohol active ingredient in sanitisers. This compound is composed of Carbon (C), Hydrogen (H) and Oxygen (O).

Isopropyl alcohol (C3H8O) is another very common active ingredient used in sanitisers. This compound is again composed of Carbon (C), Hydrogen (H) and Oxygen (O).

Positives:

  • Effective against bacteria and viruses.
  • Broad and immediate action

Negatives:

  • Strips moisture from the skin, potentially causing irritation and reduced natural bacterial resistance to pathogens.

 

 

 

 

Quaternary Ammonium Compounds | QAC

QAC’s are catatonic disinfectants (meaning they carry a positive charge) and work by inhibiting the functions of the cell membrane through electrostatic reaction, causing leakage of the cell components and eventually destruction or neutralisation of the cell.

QAC’s are a class of chemicals that are surfactants, often used in disinfectants but also used in a wide range of other applications. They have the basic structure NR4+, but each compound has its own molecular structure. The most common QAC that is used for sanitising is Benzalkonium Chloride (C19H34ClN), therefore the one we will focus primarily on for this article.

This QAC is composed of a mixture of ABDACs – alkylbenzyldimethylammonium chlorides – a alkyl group of molecular chains.

 

Benzalkonium Chloride Chemical Structure.
Benzalkonium Chloride chemical structure

Positives:

  • Effective against most bacteria, enveloped viruses (i.e. Coronavirus) and some fungi.
  • Good stability and toxicology
  • Effective for surface sanitation due to surface-active nature.

Negatives:

  • Some strains are very dangerous.
  • Banned in some industries (i.e. Food industry)
  • Affected by organic soil.
  • Tends to cling to surfaces – can make them difficult to rinse off.
  • Requires up to 10min wait time to be effective.

 

 

Hypochlorous Acid | HOCI

HOCl is the same chemical produced by the human immune system to fight infections and kill invasive organisms. Each HOCl molecule is neutrally charged and can penetrate the cell wall, slime layers and protective layers of viruses, bacteria and other microorganisms, killing or neutralising the cell.

‘Hypochlorous acid oxidises (explodes) the cell wall of all pathogens causing necrosis (rupturing of the cell) or apoptosis (programmed cell death) and destroys them. Though viruses are not technically living organisms, they too are destroyed by hypochlorous acid.’ (British Dental Journal – https://www.nature.com/articles/sj.bdj.2018.302)

Hypochlorous Acid composes of Hydrogen (H), Oxygen (O) and Chlorine (Cl).

 

Hypochlorous acid chemical structure

Positives:

  • Highly effective against all main pathogens (Bacteria, Viruses, Spores, Fungi and Biofilm).
  • Non-toxic. Completely safe to humans and animals – Same acid as produced by our natural immune systems.
  • Very low concentration required to be effective.
  • Safe to use in Food Processing/Manufacturing plants
  • Effective as a disinfectant and sterilising agent.

Negatives:

  • Limited shelf life

 


 

How efficient are each of these sanitisers?

 

 

What sanitiser should I be using?

 

So… alcohol-based sanitisers and alcohol-free sanitisers are BOTH effective; it simply depends on the purpose and objective of your sanitation.

 

Personally, I will almost ALWAYS recommend a sanitiser with Hypochlorous Acid (HOCl) as the active agent. It is the most natural and effective known biocide known to man – eradicating all bacteria, viruses, spores, fungi and biofilm. ‘It disinfects 200 to 300 times better than bleach’ and the most amazing part – it is 100% safe to humans and animals!

 

Other summary points:

  • For hand sanitising to combat viral infection, an ethanol-based sanitiser with 80% or greater alcohol concentration is most effective.
  • For hand sanitising to combat bacterial infection, an isopropanol-based sanitiser with 80% or greater alcohol concentration is most effective.
  • QAC’s are most effective for surface sanitation.
  • If you require complete sterilisation of all main pathogen groups (Bacteria, viruses, spores, fungi and biofilm), this is where Sodium Hypochlorite is most used.
  • Hypochlorous acid is a completely non-toxic alternative in this situation, with the same ability to disinfect all the main pathogen groups, whilst being 100% safe.

 


Denver Prestidge, business development manager

About the Author:

Denver Prestidge is a fresh Industrial Hygiene and Air Quality apprentice for Presco Environmental.

Focused on sourcing and developing innovative, industry leading products for New Zealand’s food producers, Denver is always looking for ways to challenge and improve the status quo.

If you would like to get in touch with Denver, feel free to reach out at any time – denver@presco.co.nz.


 

References

 

 

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