Performance : Excellent
Quick acting & long-lasting

Simulating a 'splash' of contaminated water; then testing efficacy after artificial ageing

4MED was tested using a modified procedure based on ISO 22196, using a suspension of E Coli in water, simulating a splash of contaminated water. The sample was tested at various time intervals to determine how fast the coating destroyed the bacteria. The test was repeated after artificially ageing the test samples by 120 dishwasher cycles.

The graph shows 4MED achieving a fast rate of kill of the bacterial population, resulting in a reduction of 99.5% in three hours and a reduction to below the limit of detection in six hours.

The artificially aged samples produced similar results. The test samples were reduced to below the limit of detection within 6 hours. Simply stated, the 120 dishwashing cycles did not have a statistically significant impact on the performance of 4MED antimicrobial efficacy.

Simulating a 'splash' of contaminated heavy soil / body fluids

The sample used in this test is a mixture of vegetable oil and bovine albumin serum simulating a heavy soil or body fluid contaminated with E Coli. Using a modified version of the ISO 22196 test, a reduction in the growth of the bacterial population of 99.5% was achieved within 24 hours

Efficacious against antagonistic agents

The antagonists fall into two types, proteins and cleaning agents. Subsequently, the sample pieces were tested against E Coli and the surviving populations determined by the method described in ISO 22196.

Proteins can act as competitive inhibitors to the coating, either by blocking the release of the antimicrobial additive or absorbing it. The protein antagonist tests involved egg albumin, widely used in the food industry, and full-fat dairy cheese. Both substances are rich in cysteine. The results, in Table 1, show clearly that exposure had no impact on antimicrobial activity.

The surfactants and disinfectants were chosen to represent the major groups used in cleaning systems. The results in the table below show that the immersion of the test pieces in anionic, cationic and non-ionic surfactants had no impact on the activity of 4MED. Exposure to sodium hypochlorite and gluteraldehyde has imparted biocidal activity to the untreated coating but on subsequent examination, does not appear to have affected the substrate in any way. Both substances are notorious for damaging surfaces, but it has not happened in this case. Exposure to a peroxygen donor-based disinfectant also had no impact on 4MED activity. Multiple exposures to high pressure steam was used to simulate high pressure washing. This also had no impact on 4MED's antimicrobial activity

Activity of 4MED against E Coli (suspended in 1/500 Nutrient Broth)

after 6 hours contact with antagonists

Geometric mean of 3 replicates as CFU cm^-2

Test Results

Determination of Antibacterial Activity using Test Based on JIS Z 2801:2000

IMSL 2007 11 010 1A Certificate 120 dishwasher cycles

IMSL 2007 11 010 2A Certificate Stain Resistant