A study published in the journal Emerging Infectious Diseases, says that the N95 respirator, touted to be the most effective in preventing the entry of viruses and bacteria, can be used thrice after decontamination.

The authors, including the researchers from the University of California, of the study suggested that the N95 respirator can be used after decontamination even if it has contracted the SARS-CoV-2 before.

Researchers noted that N95 respirators reduce exposure to airborne infectious agents.

The researchers said that the reuse of the N95 respirator will help the health administration address the shortage of the device.

Study co-author James Lloyd-Smith from UCLA said in a statement: “Although N95 respirators are designed for just one use before disposal, in times of shortage, N95 respirators can be decontaminated and reused up to three times. But the integrity of the respirator’s fit and seal must be maintained.”

For the research, the scientists examined four decontamination methods on small sections of N95 filter fabric that had contracted SARS-CoV-2. The researchers said that all four methods destroyed detectable virus from the N95 fabric test samples.

The scientists then treated fully intact, clean respirators with the same decontamination methods to test their reuse durability, following which they asked some volunteers to wear the masks for two hours to determine if they maintained a proper fit and seal over the face.

They decontaminated each mask three times, using the same procedure with each.

According to the study, masks treated with vaporised hydrogen peroxide experienced no failures, suggesting they potentially could be reused three times.

Those treated with UV light and dry heat began showing fit and seal problems after three decontaminations, indicating these respirators potentially could be reused twice, the researchers said.

They concluded that vaporised hydrogen peroxide was the most effective method because no traces of the virus could be detected following a mere 10-minute treatment.

Researchers also asked people who wish to decontaminate an N95 respirator to closely check the fit and seal over the face before each reuse.