Fact Check-Microscopic fibres in face masks, swabs and sanitary pads are not living organisms; they are safe fibres that move due to static or moisture

Social media users have continued to misinterpret videos of moving fibres in COVID-19 test swabs, face masks and sanitary pads as tiny living worms.

As Reuters has outlined in a previous fact check (here), these videos actually show safe synthetic fibres under a microscope that move due to static electricity or moisture.

Despite the debunking of a series of videos that dissuade people from using face masks and test swabs, similar claims have emerged (here). Some users have also expanded their experiments to sanitary pads and nappies (here). One user wrote: “After seeing the Post (sic) about nappies.. I decided to try out my spare back up sanitary towels..Wilkos own brand! They have THE SAME WORM PARTICLES AS THE NAPPIES!! I'm convinced this is why women are having bad periods!” (here).

These images do not show live particles or worms. Medical experts at the Meedan Health Desk (here) wrote in an explainer (here) that synthetic fibres in such products can sometimes move due to static electricity. This is a process also explained in a BBC explainer for school pupils (here).

Moisture absorbed from human breath or water is another reason for movement (here), which explains why a fibre “appears to come to life” in a “warm breath test” that has been viewed over 14,000 times on Facebook (timestamp 40, here).

The Meedan experts added that real microscopic worms would not survive on dry products like face masks because they need to be surrounded by water. They also pointed out that worms would look different to fibres under a microscope, due to their organs being visible, as well as other characteristics.


False. Videos do not show microscopic worms in products such as face masks or sanitary pads, but synthetic fibres that are completely safe and sometimes move due to static electricity or moisture.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here .