In June 2020, Belgium received a delivery of 15 million cloth masks from a company based in Luxembourg. Residents could pick up the masks for free in local pharmacies.
The masks sold by a company called "Avrox" are now suspected of being potentially harmful.
According to a confidential report from the Belgian Institute for Public Health, the fabric contains nano silver and titanium dioxide, which can be toxic if they are released.
These nano particles, which are supposed to have an antibacterial effect, can be particularly harmful to people already struggling with respiratory problems.
While the Institute refused to comment on the report in front of the cameras of Belgian broadcaster RTBF, it did state in a press release that the study is not available to the public at the moment. The Institute explained that there are still uncertainties as to whether the nano particles are actually being released.
While Avrox is based in Luxembourg, the masks were manufactured in Asia.
Belgium still has around three and a half million of these masks in stock.