Sporicidal_Disinfection

About Sporicidal Disinfection

Most of the time companies that sell disinfectants state on
their packaging or website that their product kills "99.9% of
germs", "kills all know toilet germs" or something similar. They are essentially taking advantage of your lack of knowledge about the harmful pathogens that are in our environment. To help you shop for your home infection control products we have put together some information to help you choose the right product for your needs. We've tried to be as unbiased as we can, and we are certainly not saying that the Tristel products are necessary for everyone (see vulnerable people).

What are germs?

A germ is the non-scientific term for a microorganism.
Microorganisms are extremely small and are not visible to
the naked eye. They are the most abundant forms of life on
earth and come in different types and strains. They exist
practically everywhere in the world and some are good for
us and some are harmful to us.

What are the different types of germs?

Germs fall into different scientific categories: bacterial
spores, mycobacteria, bacteria, fungi and viruses.

Can you give me examples I might have heard of?

Bacterial Spores: Clostridium difficile (also known as C. diff).
Mycobacteria: Tuberculosis.

Bacteria: Clostridium difficile, Enterococcus coli (also
known as E. coli).

Fungi: Aspergillus niger.

Viruses: Hepatitis A, B and C, HIV, Norovirus (also known
as Winter vomiting virus), Influenza, SARS.

What is biocidal performance of disinfectants?

For a product to be classed as a disinfectant it must be biocidal. This means that it is capable of killing one or more of the types of microorganisms shown above. More specifically, if it can kill spores then it is sporicidal, mycobarteria then it is mycobactericidal, bacteria then it is bactericidal, fungi then it is fungicidal, and viruses it is virucidal.

Spores are the most difficult form of microorganism to kill and they are said to be the most resistant. This means that if a disinfectant claims to be sporicidal, it is almost certain to be mycobactericidal, bactericidal, fungicidal and virucidal. The
following diagram explains the resistance hierarchy of the
germ types:

So when choosing a disinfectant you should check to see
what it's biocidal performance is. If it simply states that it kills
germs then it is not really telling you anything scientific. Also,
for a product to be sold as bactericidal for example, it must
have passed the appropriate European testing standards.
Therefore, shop for products that claim to be biocidal
because at least they should have passed some sort of
tests.

Most importantly, what is the disinfectant contact time?

The contact time of a disinfectant is the time that it takes to
destroy the germs that it says it can kill. This is
extremely important because this reflects the practical use
of the products. For example, if a product doesn't say how
long it needs to be in contact with a surface for, then you
stand no chance of knowing that it will kill the germs that in needs to before it dries out. If the product states that it is bactericidal or fungicidal then it should have passed EN 13697. However, the contact time that needs to be passed for this standard is 5 minutes, which is actually a very long period of time. For it to be effective, you will need to make sure that you can keep the disinfectant at the correct concentration of liquid, and in contact with the surface for that amount of time; otherwise it is not proven to work.

The Tristel products are so popular in hospitals because
they have been proven to be sporicidal with a contact time
of just 30 seconds. There are other chemicals that can be
used that have a similarly short contact time like peracetic
acid, and hypochlorous acid (link to ordinary cleaning and
disinfectant products). But these are really nasty dangerous
chemicals that nurses would certainly not want to use around
patients. And they would not be appropriate for home use
either.