The Science Behind N-95 Masks

By Kuhu Bhattacharya


The novel coronavirus pandemic had come as a bolt out the blue. With schools, shops and public places closing down, fear had filled the air. At the beginning of the global crisis, we were all forced to adapt to a “new normal”. Online activities rose and masks became the new uniform.

The N-95 mask, also known as the Non-Oil- 95% efficient mask was seen gaining the most popularity amongst all masks; but what makes it so special?

The astounding science behind the manufacturing of this one mask!

How does a N-95 mask work?

It would be very difficult to breathe through a dense, strainer-like mask with tiny openings to block microscopic particles. N95 masks take advantage of one of the characteristics of tiny things: their property of being sticky. Due to Van Der Waals force of attraction, the particles that touch a fiber will stick to it thus preventing the further movement of the same.

By creating an array of fibers between the particle and a person’s mouth, N95 masks can catch both large particles as well as small ones. They have a comparatively harder time with medium-sized particles as airflow around the fibers helps these particles avoid them.

However, N95 masks have a solution for it too! The fibers of the mask possess an electric charge, which helps them attract particles of all sizes and capture them.

Is a N-95 mask efficient?

There have been several studies which have examined the efficiency of these masks broadly based on 4 main categories: Breathing, Talking, Jaw movement and Coughing.

N95 respirators are usually tested against non biological particles. The penetration of biologic particles through the respirator filters may vary from that of their corresponding non biological simulations.Results of a study demonstrated that N95 masks were reprocessed using ethylene oxide sterilization.Though masks that are up to 11 years past expiration, maintain very high filtration efficiency under laboratory conditions, N95 masks with suboptimal fit still have a comparable filtration efficiency of more than 90%.


Though we are almost at the end of this deadly ailment of the SARS-CoV-2 or simply, the Covid-19 pandemic with the introduction of vaccines, we must consider and ponder over the science behind it.


  1. N95 masks explained. Home. (n.d.). Retrieved May 2022, from,have%20a%2099%20percent%20efficiency

  2. Sharp, N. (2020, July 14). How N95 masks work. FYFD. Retrieved May 2022, from

  3. Jama Internal Medicine—Anu Name And More - (n.d.). Retrieved May 2022, from

  4. Effectiveness of N95 masks against SARS-COV-2: Performance efficiency, concerns, and future directions. ACS Publications. (n.d.). Retrieved May 2022, from