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Author Topic: What percentage of germs does bleach kill?  (Read 13914 times)

Andy

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What percentage of germs does bleach kill?
« on: 16/02/2009 18:07:12 »
Andy asked the Naked Scientists:
   
Well known disenfectant brands advertise "kills 99.9% of all germs",
does this mean it kills 99.9% of the number present on a treated surface or 99.9% of the types of bacteria commonly found?

What do you think?


 

Offline Don_1

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What percentage of germs does bleach kill?
« Reply #1 on: 16/02/2009 18:15:04 »
It's the manufacturers 'get out' clause. In fact bleach will kill any germs, but that 0.1% just keeps them on the safe side, just in case.
 

Offline Chemistry4me

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What percentage of germs does bleach kill?
« Reply #2 on: 17/02/2009 08:04:21 »
I doubt it really will be 99.9%. It'll also depend on how you use it.
 

Offline Phil1907

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What percentage of germs does bleach kill?
« Reply #3 on: 01/03/2009 15:29:53 »
These are not "get out"clauses.   The EPA regulates these products and has specific protocols that have to be followed and the products registered before they can be sold with the claims.
Sanitizers reduce the counts of specific bacteria by 99.9% and disinfectants completely kill the bacteria.  The bugs are Staph aueus, Salmonela and Pseudomonas aeruginosa.

There's no way they could or do claim to kill 99.9% of all germs.  We can grow only a small % of the world's bacteria in the lab so they could never get the data.
 

Offline Bored chemist

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What percentage of germs does bleach kill?
« Reply #4 on: 01/03/2009 19:36:45 »
IIRC the tag line on the advert was "kills all known germs; dead." which is correct - if you use enough hypochlorite you will destroy any bacteria, viruses, fungi or whatever simply because hypochlorite destroys proteins.
 

Offline Phil1907

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What percentage of germs does bleach kill?
« Reply #5 on: 02/03/2009 00:07:20 »
What advert?   
 

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What percentage of germs does bleach kill?
« Reply #5 on: 02/03/2009 00:07:20 »

 

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