A Simple Rubber Band Trick Can Improve Surgical Mask Seal to N95 Levels, Study Shows

Surgical masks are usually inferior to N95 respirators because they lack a seal around a user’s face to protect against exposure to particles. 

N95 masks are considered the gold standard of personal protective equipment, and they have been the most sought after whether it is for protection from air pollution or that from air-borne infections like Covid-19. However, while a standard surgical mask is easily available, N95 respirators are more expensive and more difficult to produce and access.

Surgical masks filter 95% or more submicron particles but they are less protective against air-borne infections because they lack a seal around a user’s face to protect against exposure to particles that may be carrying a virus. 

A new study has now shown that a simple modification to these surgical masks can improve their protective seal to the level of N95 respirators. As part of the study, a surgical mask was modified using rubber bands to create a protective seal against particle exposure. The study tested the performance of this modified surgical mask and found that it passed N95 standards.

The study conducted by a research team led by a surgeon at Michigan Medicine, University of Michigan, was recently published in PLOS ONE.

According to the university, the team worked with 40 healthcare workers to test the normal surgical masks that were modified with “two 8-inch rubber bands over the crown of the subject’s head, bridge of the nose, around the cheeks and under the chin within the boundaries of the mask”.

To achieve the protection level of N95, the respirators had to demonstrate a minimum score of 100 on a standardised number of tests — the passing threshold set by the Occupational Safety and Health Administration — against the passage of particles with the potential to expose the wearer to infection. 

What The Study Found

As many as 31 subjects — 78% of the total 40 — wore modified masks that passed the fit test with a score of greater than 100, the study said. An average of 151 was the score of the passing masks, which is significantly better than a standard surgical mask score of 3.8. A properly fitted N95 mask scored 199. But by the last day of the investigation, the study claimed, all of the modified masks passed the N95 threshold. A greater experience with the use of bands improved the fit and performance of the masks, the researchers found.

Jaimo Ahn, senior author of the paper and professor of orthopaedic surgery at University of Michigan Medical School, said this easy modification could address N95 respirator shortages worldwide, especially in under-resourced regions, and provide healthcare workers and individuals practical means for increased personal protection.

Stating that this approach strasses “prevention rather than treatment”, Ahn said: “While not sophisticated, it has the potential to save lives and preserve wellness. Its effect will last as long as there are respiratory diseases and PPE demand exceeds supply. It is immediately impactful and sustainable, yet simple and cheap.”