Plastics. Measurement Of Antibacterial Activity On Plastics Surfaces (British Standard)
ISO 22196:2007 specifies a method of determining the antibacterial activity of antibacterial / anti-microbial-treated plastic products such as our Si-Quat Products.
In this test the coating has been tested through an aging process to certify the activity after 12 months.
It is not intended to be used to evaluate the effects and propagation of bacteria on plastics without antibacterial treatments and is specifically designed to test products like Si-Quat and Clean N Coat. ISO 846 describes tests to evaluate the effects and propagation of bacteria on plastics, which are different from those covered by ISO 22196. For some test it is good to test plastics that are not treated to create a control group. Secondary effects of antibacterial treatments, such as the prevention of biodeterioration and odour, are not covered by the standard although it would be a side effect of our Si-Quat active coatings.
SUMMARY OF THE ISO 22196 TEST
The test microbes are prepared, usually by development in a liquid culture medium. Per the method, two representative microbes are specified, S. aureus and E. coli. Are standard and also used by AFFIX Labs to test the Si-Quat active coating.
The suspension of the test microorganism is standardized by dilution in a nutritive solution that enables the bacteria to grow during the test.
Control and test surfaces are inoculated with microorganisms, and then the microbial inoculum is covered with a thin, sterile cover. Covering the inoculum helps it spread better and prevents it from vaporizing, it also helps to ensures close contact with the antimicrobial surface which is needed for a mechanical kill like with our Si-Quat active molecule.
Microbial concentrations are established at the start of the test by elution followed by dilution and plating.
A control is run to verify that the neutralization/elution method effectively neutralizes the antimicrobial agent in the antimicrobial surface being tested.
All the samples and control group are incubate and remain undisturbed in a humid environment for 24 hours.
After incubation, microbial concentrations are determined. The reduction of microorganisms relative to initial concentrations and the control surface is calculated.