knowledge bank

Why can't you use masks with air valves under pandemic

On November 25, 2021, the Centre for Health Protection (CHP) of the Department of Health of the Government of the Hong Kong Special...

Respirators, such as N95 and EN149 FFP2 NR, are designed in a three-dimensional figure. Their edges are close to the face to ensure that...

As COVID-19 raged for more than two years, vaccination and wearing masks are the most important protection measures against infection. In...

The National Institution of Occupational Safety and Health (NIOSH) in the United States is and the only agency authorized to issue N95...

Living with the overwhelming COVID-19 pandemic for more than two years, it is known that wearing masks is a vital protection against...