Personal protective equipment including masks are vital for protecting healthcare workers from infection with covid-19. But during this pandemic with masks in high demand by hospitals and individuals alike it's not surprising that many institutions are facing shortfalls and are left scrambling to find alternatives.
There are two basic mask types commonly used in a clinical setting:
- SURGICAL MASKS - These masks are generally loose-fitting and provide good protection against larger droplets. This refers to coughs and sneezes.
- N95 RESPIRATORS - Just in contrast with the surgical masks the N95 respirators which form a tight seal around the nose and mouth protect better against small aerosolized or airborne particles and are therefore considered the best type of protection against Covid-19.
Now, many regulatory bodies such as FDA have guidelines for how to address a shortage of appropriate masks during a global pandemic.
- Single use masks to be worn continuously throughout an entire shift known as extended use.
- Or allowing masks to be removed and put back on multiple times between patients within the same shifts which is known as reuse.
Many institutes around the world are already requiring their staff to reuse the Masks. But what are the risks of reuse?
According to CDC the most significant risk of reuse and extended use is contact transmission i.e.,the person might touch the surface of a contaminated respirator and then infect themselves by touching their face.
It was found out in a study that nurses touch their face, eyes or N95 Respirators an average of 25 times per shift during extended use. In addition to all of this the respirators could also be contaminated with other common hospital pathogens MRSA etc., which could also be transmitted through direct or indirect contact.
To reduce the risk of contact transmission the CDC recommends using a cleanable face shield over an N95 respirator to avoid contamination and also that the respirators be discarded if they are obviously contaminated or damaged or are hard to breathe through them.
It is also a very vital point that those who wear these masks should wash their hands thoroughly before and after touching the respirators.
Since the masks are in short supply so is there a way to disinfect, cleanse or decontaminate these masks between uses?
Any decontamination process should not compromise the proper fit of the mask while maintaining the mask ability to filter out small particles like the virus. In 2009 a team at the National Institute of Occupational Safety and Health also called NIOSH showed that a single treatment with hydrogen peroxide vapor, UV irradiation or dry heat below 100 degree Celsius did not affect the ability of N95 masks to filter small particles. Although they didn't look at whether their treatment protocols were effective in decontaminating nor whether they affected the proper fit of the mask. This study paved the way for several more recent investigations.a group at Duke University recently released a procedure for sterilizing N95 masks using hydrogen peroxide vapor. Their technique did not alter the fit of the mask it left no residue other than water and it provided valid decontamination. Although they didn't use coronavirus but instead tested using other biological indicators. Using this technique they were able to repurpose 500 marks in one roughly four hour cycle. They also suggest that most masks could undergo this process at least 30 times without loss of fit.
FDA has finally approved the decontamination of masks using the STERIS sterilization systems.
What is the STERIS sterilization for bio decontamination?
STERIS is known to deliver a complete solution for sterilization or decontamination all over the world. Steris's proprietary dry process helps ensure that peroxide remains in the vapour phase without potentially damaging condensation or fog enabling significant advantages compared to alternative technologies. The advantages being:
- Safety: PHP decomposes into harmless by-products water and oxygen upon completion of the process.
- Speed: high capacity next generation equipment reduces cycle times. Thus decontaminating a lot of marks in a less period of time.
- Efficacy: VHP is proven to destroy a wide range of microorganisms including bacteria viruses and fungi. Thus safeguarding us from Novel Coronavirus.
- Material Compatibility: The dry VHP process safely decontaminates the most sensitive of the layers of the mask.
- Convenience: It has a world class service team with expertise located around the globe to manage the project very well.
What are the strict guidelines laid on by FDA to be followed while undergoing the decontamination of the masks?
FDA has surely given a green flag to the decontamination, cleaning or disinfecting of masks at a higher numerical level due to the deficiency of masks all around the globe but there have been some very strict ground rules laid by FDA. Following are the guidelines by FDA that are to be followed while cleaning or decontaminating of the N95 masks for their reuse:
- The STERIS sterilization systems are forbidden from bringing in use the following:
- Respirators containing cellulose-based material.
- Restorations with an exhalation valve incorporated.
- Respirators not authorized by NIOSH
- The N95 respirators that are to be sterilized should be free of any visible damages or should not be soiled specially from blood, makeup or body fluids.
- The soiled N95 respirators need to be discarded immediately.
- The respirators whose number of decontamination cycles cannot be recorded backward should also be discarded.
- Decontaminated compatible N95 respirators are not sterile.