Copper masks are masks infused with a copper metal mesh layer; copper oxide is known to display antiviral properties.
Research shows that copper oxide impregnated face masks may filter above 99.85% of aerosolized viruses when exposed to the H1N1 virus and avian influenza virus (H9N2) under simulated breathing conditions . Another important finding from the research was that no infectious viral titers were recovered from the copper oxide masks within 30 minutes.
A cloth mask embedded with a copper mesh filter can significantly increase its efficacy and can be a viable alternative to a better mask unless being exposed to an environment that requires surgical masks .
Impregnation of copper oxide into protective face masks enables them with potent anti-influenza biocidal properties without making any change to their physical barrier properties. This will assist in significantly reducing the risk of hand and environmental contamination and hence subsequent infection due to improper handling and disposal of the masks.
Several tests carried out show that the amount of copper eluted to air from test mask in a time period of 5 hours under simulated breathing conditions was 0.467±0.47 pg, which is far below the respiratory copper permissible exposure limit (PEL) set by USA Occupational Safety and Health Administration (OSHA) . The outer layers of the masks which contain copper oxide particles also did not cause any skin sensitisation or skin irritation.
Properties of copper masks
Mass distribution of copper masks was done in Hong Kong around the month of May. CuMask+™, developed by the Hong Kong Research Institute of Textiles and Apparel (HKIRTA) consists of six layers with two layers specially made with small quantities of copper as shown in Figure 6.
This is capable of deactivating bacteria, common viruses, and other harmful substances. CuMask+™ complies with the American Society for Testing and Materials (ASTM) standards for particle filtration efficiency, bacterial filtration efficiency, resistance to penetration by synthetic blood, flammability, and pressure resistance .