How can we ensure facemask efficacy and availability?

Can facemasks be steam-sterilised like other equipment?

Hospitals around the world use steam to effectively sterilise hospital equipment and instruments. Many hospitals asked TNO if the same steam could make hospital-grade facemasks reusable. They hoped this might prevent a supply shortage during the coronavirus outbreak. Roberto Traversari and Jos van der Vossen, specialists in contamination control at TNO, developed a test to find out.

TNO already had a method to test the protective properties of packaging material for medical equipment after heat sterilisation. With a few modifications, that same test was used on facemasks. More than 50 healthcare organisations steam-sterilised a hospital-grade mask and sent the sample to TNO to determine the effect on the mask’s efficacy and efficiency. ‘The conclusion was not positive,’ Roberto concludes. ‘The FFP2 masks currently on the market are primarily for single use. The majority of the masks we tested were damaged by the steam, and therefore were no longer effective. In line with this, reuse of facemasks after heat sterilisation should not be common practice unless a specific mask thoroughly tested for this.’

Microbiology expertise needed now more than ever

TNO set up an accelerated testing process and a methodology for constantly improving testing capabilities, together with testing teams at private companies and Dutch universities. ‘Our primary focus is on the materials that the facemasks are made of. We can offer advice and insight into potential alternative materials in the event that hospital-grade masks are running low.’

But the efficacy of a facemask is not only based on the material’s filtering ability. The mask’s fit and potential for leakage are also factors. In March, TNO tested FFP2 facemasks delivered to the Netherlands. The test revealed that nearly half the supply was defective. ‘In a shipment of 1.3 million FFP2 masks, we discovered that 600,000 were ineffective, either due to improper fitting around the face which causes leakage, or defective membranes intended to filter out virus particles. That’s why it is so important for healthcare organisations to test a sample facemask before making a large purchase. TNO can help determine if the masks satisfy the regulatory requirements for protection. Unfortunately, an FFP2 label is not enough to ensure this.’

TNO helps address challenge of diminishing supplies in developing countries

Questions have also come in from developing nations about the challenge of diminishing supplies and rising infection rates. The team recently helped a non-profit organisation focused on Nepal. Healthcare workers there were struggling to find effective alternative materials to support their depleting facemask supply. ‘We’re happy to answer questions about material efficacy,’ Roberto says. ‘We can also test the protective capacity of different materials, test the effect of sterilisation attempts, or advise about resources for the purchase of effective masks.’

Latest scientific insights for the efficacy of facemasks

In developing countries, TNO can contribute its knowledge and insight, collected from years of extensive research. We’re looking for partners that aim to develop reusable, hospital-grade facemasks or to set up expert panels or laboratories for wide-scale testing. All that is needed is the right partners with the drive to help find solutions.

Do you have a question about facemask material testing? Are you wondering if the facemasks you bought are effective? Want to develop a reusable, effective facemask and need expert advice? Contact TNO to explore the possibilities.

This TNO project supports the following sustainable development goal