How do infectious diseases spread?
Disease causing microbes are commonly spread by tiny droplets of body fluids, for example from when we cough or sneeze. A single droplet can contain enough microbes to cause infection. Where those droplets land on our hands, or surfaces that we frequently touch, spread of the infection can occur.
When we touch surfaces, any microbes on our hands can be transferred to that surface. When someone else then touches the surface and then their face, the microbes can be passed on. This is why we are reminded to wash our hands and avoid touching our faces to avoid infectious diseases.
Many microbes can live for several days on materials such as stainless steel, ceramic tiles or plastics.1 On copper-based materials however, the number of surviving microbes rapidly decreases, often becoming undetectable in hours or even minutes. 1
How does the KeepSafe help?
- It prevents direct contact with commonly touched surfaces. This reduces the chances of you transferring microbes to or from that surface to yourself or anyone else using that surface.
- The area of contact with surfaces is likely to be much lower than if you use your hands or fingers directly, so the chances of picking up microbes are lower.
- It is made with a copper-based alloy, so any microbes that do get on to the device will have much shorter survival times than they would on other materials, or your hands.
Which infectious diseases has copper been tested on?
Laboratory tests have shown copper to be highly effective in killing a broad range of bacteria and fungi, and inactivating viruses. 2 These include human coronaviruses responsible for respiratory diseases ranging from the common cold to pneumonia1, MRSA, VRE, E. coli, influenza, norovirus, C. difficile, Enterobacter aerogenes, Pseudomonas aeruginosa, Acinetobacter baumannii, Listeriamonocytogenes, Klebsiellapneumonia, Salmonella enterica, Campylobacter jejuni, Candida albicans, Fusarium culmorum, Fusarium oxysporum, Fusarim solani, Penicillium chrysogenum, and Legionella pneumophila. 2
Clinical trials showed an 83% reduction in bacteria on touch surfaces when replaced with copper. This resulted in a 58% reduction in hospital acquired infections. 2
What about Covid-19?
The virus responsible for the current coronavirus pandemic, or Covid-19, is officially known as SARS-Cov-2. In laboratory tests, the virus was undetectable on copper surfaces in only four hours. This compared to up to 72 hours for stainless steel and plastic surfaces. 3
The number of virus particles decreased exponentially on the copper surface, with the number halving approximately every 1.1 – 1.2 hours. On stainless steel it took almost five times as long at 5.6 hours, and on plastic even longer at 6.8 hours. 3
How does copper inactivate microbes?
The exact mechanism differs between microbes. 1 However, in general terms, ions (electrically charged particles) are released from the copper when microbes land on the surface. The ions cause the physical breakdown of the outer structures of the microbes, prevent them from respiring, and breakdown the DNA or RNA inside that is required for replication. 1,4
The destruction of the DNA or RNA is particularly important, as without it the microbe cannot reproduce or mutate, which means they cannot develop resistance to the copper, or transfer resistant genes between microbes. 4
In the case of bacteria, they can also produce small amounts of hydrogen peroxide. This reacts with the copper surface to create highly reactive oxygen radicals that attack and damage the bacteria further. 4
How long does copper work for?
The beauty of copper, is that its properties are permanent and work 24/7. Even if it becomes tarnished, it still works. Moreover, it works on resistant microbes such as MRSA, those for which we have no vaccine such as norovirus, and those that rapidly mutate making annual vaccination necessary such as influenza.
What alloy do you use?
The KeepSafe is a copper-zinc alloy with a minimum 79% copper content.
Hygiene and cleaning
Copper surfaces reduce the risk of transmission of infectious particles, but do not eliminate it entirely. It is therefore still essential to maintain good hygiene, a regular and thorough cleaning regime, and to follow government and workplace guidelines on preventing the spread of infectious disease.
1. Warnes, S. L., Little, Z. R. & Keevil, C. W. Human Coronavirus 229E Remains Infectious on Common Touch Surface Materials. Mbio 6, e01697-15 (2015).
2. Michels, H. T., Keevil, C. W., Salgado, C. D. & Schmidt, M. G. From Laboratory Research to a Clinical Trial. Herd Heal Environ Res Des J 9, 64–79 (2015).
3. Doremalen, N. van et al. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. New Engl J Medicine 382, 1564–1567 (2020).
4. Keevil, C. W. Copper is great at killing superbugs – so why don’t hospitals use it? The Conversation (2017).