Radiation effective for PPE, but not masks, says IAEA

01 May 2020

Radiation is an "effective and established" tool to sterilise personal protective equipment (PPE) that is in high demand during the COVID-19 pandemic, except for respiratory face masks as it weakens their filters, the International Atomic Energy Agency (IAEA) said yesterday.

Tests carried out by institutes in France, Israel, Republic of Korea, Poland, and the USA showed that the level of radiation required to sterilise respiratory face masks decreased their filtering performance (Image: IAEA)

The IAEA has reviewed findings from five institutions that tested the use of ionizing radiation - gamma and electron beams - to sterilise used respiratory masks, such as models N95 and FFP2 commonly worn by medical personnel.

"Many governments are looking to expand the availability of PPE by sterilising them with chemicals, UV light or radiation," said Celina Horak, radiation processing specialist at the IAEA. "Face masks are of particular interest, as they are indispensable for hospital staff but also used among the general population for protection while shopping or using public transport."

N95 and FFP2 masks filter out at least 95% of external airborne particles, but they differ from surgical masks, which for the most part only guard others against the wearer’s own respiratory emissions.

Byungnam Kim, head of the irradiation facilities at the Advanced Radiation Technology Institute of the Korea Atomic Energy Research Institute, which carried out tests using electron beams, said masks showed no significant changes in fit or measurable structural changes when exposed to the 24 kGy dose of radiation needed to kill viruses and bacteria, but filtering capacity was "significantly compromised".

About 50% of healthcare products, such as gloves, syringes and single use protective clothing, are sterilised using gamma rays, electron-beams or X-rays prior to their use.

Researched and written by World Nuclear News