Dear Member

Following the recent announcement by Prof Keevil at a conference in Bejiing that copper is effective against Influenza A (H1N1), the body of scientific evidence for antimicrobial copper continues to grow. A recently published study compares the performance of copper and silver under indoor conditions and a new trial has been launched to investigate the health benefits of copper for air conditioning systems. On the practical application side, CDA is working with manufacturers to develop new products which exploit copper's antimicrobial efficacy, engaging healthcare contractors to offer 'ward packages' and talking to trusts who are interested in incorporating copper in the clinical environment.

CDA will be exhibiting and presenting at a variety of events in the coming months and we would be happy to see you on our stand. For details please click here.

In this issue:

Copper and silver - how do they compare?

Design guidance

Copper - a breath of fresh air?

Silver and copper have been used for their antimicrobial properties for centuries and now manufacturers are incorporating these metals into consumer products, particularly touch surfaces, and making antimicrobial claims. A new study, published in Letters in Applied Microbiology, answers the question of whether these applications actually work under real-life conditions. Materials containing silver-ions have been shown to be effective under conditions of high temperature (35°C) and high humidity (90% or higher relative humidity), but until this study, they had not been tested at lower temperature and humidity levels typical of indoor environments, such as those found in hospitals.

The researchers used copper alloys as a point of comparison because laboratory testing has shown that they are effective in reducing over 99.9% of bacteria within two hours at room temperature and normal humidity (50%). The silver ion materials showed no measurable antimicrobial efficacy and behaved as the stainless steel controls whereas the copper showed a seven log reduction in 75 minutes. This data, along with clinical trial data, supports the use of copper for antimicrobial touch surface applications for indoor environments.

Design guidance

CDA has produced some new publications on antimicrobial copper touch surfaces aimed at architects, designers and specifiers. The Specifiers' Guide is launched with a series of one-pagers covering architectural ironmongery and provides an overview of available alloys, colours, product forms, finishes and typical dimensions. Next in the series will be sanitary fittings.
Specifiers' Guide

A new introductory brochure for architects and designers is also now available.
The Benefits of Designing with Antimicrobial Copper Alloys

New research is under way to investigate how copper can combat the bacteria and fungi that cause foul odours and reduced efficiency in HVAC units where the damp and dark environment is the perfect breeding ground for germs.

The trial is comparing the ability of copper and more commonly used aluminium HVAC components to control the growth of odour-causing bacteria and fungi in HVAC units. Components being replaced with copper are cooling coils, heat exchange fins and drip pans. The study is funded by the U.S. Department of Defense and is taking place at the military barracks at Fort Jackson in Columbia, South Carolina. Professor Charles Feigley, principal investigator for the study, explained the need for this research: “Improvements in building and construction methods have generally led to increased energy efficiency but, at the same time, these ‘tighter’ building envelopes tend to trap bacteria, leading to odours. The results of this real-world trial should encourage advancements in the design of HVAC systems.”