Laboratory testing of Antimicrobial Copper reveals 3 key benefits
Extensive laboratory testing has proven that Antimicrobial Copper continuously kills pathogenic microbes, never wears out, and is safe to use.
Laboratory research on the antimicrobial efficacy of copper
alloys has been carried out and verified at leading institutions
around the world, including the UK, US, South Africa, Germany and
Japan. Results have been peer reviewed and published.
In the US, laboratory results were independently verified by the
Environmental Protection Agency, leading to the only EPA public
health registration for a touch surface material. For this
registration, Antimicrobial Copper alloys had to demonstrate
efficacy under rigorous, EPA-approved test protocols. Three test
protocols were developed to test Antimicrobial Copper's ability to
kill bacteria* that cause infections. A description of the
testing is provided below:
Required Testing for US EPA Regulatory
Approval
The three EPA approved Good Laboratory Practice (GLP) test
protocols used to register Antimicrobial Copper with public health
claims are:
- Efficacy as a Sanitizer - which measures viable bacterial count
after two hours.
- Residual Self-Sanitising Activity - which measures bacterial
count before and after six wet and dry wear cycles during which
bacteria are added in a standard wear apparatus (shown as a
schematic in Figure 1).
- Continuous Reduction of Bacterial Contaminants - which measures
bacteria after inoculating an alloy surface eight times in a
24-hour period without intermediate cleaning or wiping.
Figure 1: Residual Self-Sanitizing test protocol
schematic.
The results of the 216 GLP tests, involving three test
protocols, two to three lots of six different alloys, and six
bacteria*, are summarised in Table 1. In both the Efficacy as
a Sanitizer test and Residual Self-Sanitizing test (wear test), a
reduction in live bacteria greater than 99.9% is seen in all
seventy two tests when compared to stainless steel (S304). In the
Continuous Reduction of Bacterial Contaminants test, a reduction of
greater than 99.9% is found in sixty-three out of the seventy-two
tests, again when compared to S304. In the remaining nine tests,
reductions ranged from 99.3% to 99.9%. In summary, a
reduction greater than 99.9% was seen on 207 out of 216 tests. The
reduction seen in the remaining nine tests ranged from 99.3% to
99.9%. These results indicate that the antimicrobial response of
copper alloys is effective, enduring and reproducible.
Figure 2: Continuous Reduction test results for
MRSA on Antimicrobial Copper C11000 and Stainless Steel
S30400. Each inoculation adds 650,000 CFUs.
- Click on graph to enlarge
Table 1: Average Percent Reduction of Bacterial
Contamination (Good Laboratory Practice Studies)
|
|
Group
|
Alloy
|
%Cu
|
S.aureus
|
E.aerogenes
|
MRSA
|
P.aeruginosa
|
E. coli O157:H7
|
|
Efficacy as a sanitiser
|
I
|
C110
|
99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
II
|
C510
|
94.8
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
III
|
C706
|
88.6
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
IV
|
C260
|
70
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
V
|
C752
|
65
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
VI
|
C280
|
60
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
|
|
|
|
|
|
|
|
|
Residual Self Sanitising
|
I
|
C110
|
99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
II
|
C510
|
94.8
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
III
|
C706
|
88.6
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
IV
|
C260
|
70
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
V
|
C752
|
65
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
VI
|
C280
|
60
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
|
|
|
|
|
|
|
|
|
Continuous Reduction
|
I
|
C110
|
99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
II
|
C510
|
94.8
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
III
|
C706
|
88.6
|
>99.9
|
>99.9
|
99.9
|
>99.9
|
>99.9
|
|
|
IV
|
C260
|
70
|
99.6
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
V
|
C752
|
65
|
99.7
|
>99.9
|
>99.9
|
>99.9
|
>99.9
|
|
|
VI
|
C280
|
60
|
99.8
|
>99.9
|
99.9
|
>99.9
|
>99.9
|
*Peer reviewed scientific publications show Antimicrobial Copper
to be effective against bacteria, viruses, fungi and moulds,
including MRSA, Influenza A (H1N1), Clostridium difficile
and VRE.
Antimicrobial Copper is the only touch surface material to have
efficacy data independently verified through the US Environmental
Protection Agency (EPA) registration which supports the claim to
continuously kill more than 99.9% of the bacteria that cause HCAIs
within two hours of contact. Organisms tested are MRSA,
Staphylococcus aureus, Enterobacter aerogenes,
Pseudomonas aeruginosa, E. coli O157:H7 and
Vancomycin-resistant Enterococcus faecalis.
Further work1 has demonstrated that Antimicrobial
Copper outperforms two commercially available silver-containing
coatings under typical indoor conditions.
A study2 on a busy medical ward at Selly Oak Hospital
showed a 90-100% reduction in contamination on Antimicrobial Copper
surfaces compared to surfaces made of conventional materials.
Trials in the US and Chile confirm these results. Antimicrobial
Copper surfaces are a supplement to, and not a substitute for,
standard infection control practices and have been shown to reduce
microbial contamination.
[1] Effects of temperature and humidity on the
efficacy of methicillin-resistant Staphylococcus aureus
challenged antimicrobial materials containing silver and
copper. H T Michels, J O Noyce and C W Keevil, Letters in
Applied Microbiology, 49 (2009) 191-195.
[2]
Role of copper in reducing hospital environment contamination.
A L Casey, D Adams, T J Karpanen, P A Lambert, B D Cookson, P
Nightingale, L Miruszenko, R Shillam, P Christian and T S J
Elliott, J Hosp Infect (2009).