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Why 70% Iso propyl alcohol effective instead of other dilution?

Started by , Feb 17 2016 08:14 AM
9 Replies

Hi,

 

I need some help please.

 

Last time during HACCP Audit, the auditor asked why did we use 70% alcohol for sanitizing instead of using other dilutions. I know that it is the most effective dilution compared to other. But i need a proof to to show to the auditor that we using that study as a reference.  Tried to find one, but couldnt find it.

 

Can anyone help me regarding this matter.

 

Thank you

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Hi,

 

I need some help please.

 

Last time during HACCP Audit, the auditor asked why did we use 70% alcohol for sanitizing instead of using other dilutions. I know that it is the most effective dilution compared to other. But i need a proof to to show to the auditor that we using that study as a reference.  Tried to find one, but couldnt find it.

 

Can anyone help me regarding this matter.

 

Thank you

Hi jaejay,

 

From Google

The answer is apparently similar for both EtOH and isopropyl alcohol -

 

https://www.research...l_working_areas

https://bion3rd.word...a-disinfectant/

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Thank you Charles.C, 

 

I did explained the mechanism, but the auditor insist on the study or reliable reference that i used to refer the concentration i used. I searched for journals, but i couldnt find any.

Thank you Charles.C, 

 

I did explained the mechanism, but the auditor insist on the study or reliable reference that i used to refer the concentration i used. I searched for journals, but i couldnt find any.

 

Hi jaejay,

 

You may have been unlucky enough to encounter a nit-picker. Or one who liked playing dumb as a test.

 

If no NC was involved I suggest you simply ignore the auditor's comment.

If there was an NC involved, you may have to waste some time scanning text books or look for a standard micro. procedure using this dilution to use as a reference.

 

I recall an auditor who requested validation that maintaining foods below 4degC in a refrigerator is a "safe" procedure from a micro. POV. I was tempted to enquire if he was certified to audit Frozen Food facilities but forbearance is the safest response. :smile:

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When in doubt, check the CDC website.  They are the definitive word on sanitation.  This page is about healthcare facilities, but the statements about the effectiveness of the alcohol dilutions would be the same for a food environment.  And they would carry weight with an auditor.

 

http://www.cdc.gov/h...sinfection.html

 

Martha

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Oh, yea no NC involved. She just asked me to give her something to justify my choice. Since it is my first time doing HACCP on my own, i'm a bit nervous.  :ninja:

Thanks Charlie.C

 

 

MWidra,

 I have to start combing through the article for a backup plan if she insist on the reference. Thanks a lot  :happydance:

Hi JaeJay

 

There is a lot of literature and published studies on the efficacy of Alcohol as a sanitiser. We have also done our research as a comparison to our blended alcohol products for the Australian Market and I am curious as to why you use a 70% Isopropanol. Typical market concentrations are 60% Isoporpanol or 70% Ethanol for a number of reasons like efficacy, cost, etc.

 

Being in Malaysia I suspect Isopropanol would better suit any religious issues for you ( Ethanol is not accepted for Halal) and your supplier may only have a 70% available.

 

We also know from our research that some bacteria exhibit a stress response to alcohol, and it is reasonably well known that very high concentrations of alcohol are less effective as the water is needed to penetrate the cell membrane. ( Very loosely explained ). Perhaps this is why the Auditor is questioning your choice of a 70% and not a 60%. I would ask your supplier to produce the evidence, they are selling it to you let them earn their money.

 

Also the advice from Martha to use the CDC is great, as typically the CDC provides references to published studies which you can also use.

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Hi jaejay,

 

You didn’t actually mention what you were using the sanitizer for which might have some relevance. I anticipate the iso propyl alcohol (IPA) is cheaper.

 

I like the CDC reference but it does have one minor criticism – not updated since 2009 although  I doubt that the science base has changed that much in last 7 years plus other more recent documents are still mostly using equally old references.

The CDC article very well demonstrates that there are always pros and cons – the perfect sanitizer probably does not exist from a micro. POV.

 

Different test studies may use different reference targets which may well influence the results (see below).

 

I selected 2 fairly official-looking studies you can look at -

 

Sanitizers Study 1, 2011.pdf   237.6KB   44 downloads

Sanitizers Study 2, 2007.pdf   120.72KB   31 downloads

 

Study 1 (bacterial target), 2011, suggests WHO-EtOH (80%) is pretty similar to WHO-IPA (70%) although both were ultimately somewhat  inferior to some customized commercial products. Also contains quite a nice review.

 

Study 2 (virus target), 2007, using a variety of commercial products indicated EtOH (60%) is far superior to IPA (70%).

 

I daresay you may prefer the first one. :smile: i also daresay an auditor may relate to price differences and possibly other factors as in Saraya's post.

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A little something I hijacked from the Google:

 

"0% is optimal for most cell types, especially those with a cell wall like prokaryotes. 

Wikipedia is a little off here. The reason you add water is to make the solution hypotonic. 

The alcohol disrupts the hydrophobic forces holding the phospholipids of the membrane while dehydrating any peptidogylcan of the wall enough to cause it to become less fluid/more brittle.

Now that you have essentially made the protection of the cell like brittle glass, the hypotonicity causes the cell to swell and now easily burst.

Bacteria aren't going to last long in 100% either. They fix instead, which although irreversible takes a little longer to occur.

It's also a little more economical and less wasteful to use 70% if it's just as, if not a little more, effective

1 Thank

Thank you everyone for your opinion and help.

 

 I have passed the HACCP Audit yesterday. She didn't asked much regarding the dilution as when she came for stage 1 audit.

 

Thank you so much Guys  :happydance:


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