Before the pandemic, N95 masks or N95 respirators were some of the most popular and available respirators out there, and they also filter out dust and smoke. They’re the best disposable face mask for virus protection, with higher antiviral properties than those found in other face masks. But, the days in which medical PPE (personal protective equipment) was easily found for sale online, available to buy in wholesale or bulk, are a thing of the past.
The United States has been going through shortages of PPE and supplies, affecting mainly healthcare centers. These supplies include surgical masks, KN95 masks, face shields, gowns, and gloves. This is why learning about how to maximize the use of the existing supplies is important for healthcare facilities in the USA, and in this article, we’ll talk about some of the best sterilization techniques.
Personal protective equipment (PPE) can be sterilized and reused to maximize their availability. But, some other methods to achieve this goal are recommended first before starting with limited reuse of the equipment, particularly N95 respirators. For example, the approval by the Food and Drug Administration (FDA) still applies to expired equipment, so in times of emergency, some stocks can still be considered functional in some facilities. Here are some techniques to use before considering sterilization:
- Minimize the use of the supplies: take the necessary measures to reduce the overall need for PPE, and this should be the first step. If lowering the amount of PPE required isn’t possible, you can also prolong the lifespan of your current supplies. Some strategies to achieve this include:
- Reserving PPE only for COVID-19 patients that require direct contact, and for source control, only use other barrier precautions.
- Cancel the elective or non-COVID-19 procedures that may need PPE.
- Separate staff from patients as much as possible when contact isn’t necessary using engineering controls, like shields or physical barriers, to minimize the paths to infection.
- Rotate the existing stock of PPE: the CDC devised a strategy to reduce the need for respirator sterilization, based on the fact that the SARS-CoV-2 has a relatively short life inside the filter media.
- Issuing healthcare workers only five respirators for a five-day work shift.
- After the worker uses one respirator through an entire day of work, it is stored in a breathable paper bag, and left there until the next week.
- The same thing is done with the next respirator the following day.
This way, seven days pass between two uses of one respirator, a time that is thought to be enough for the pathogens to become inert. However, these respirators still have to be handled and treated as if they were contaminated, with precautions when putting them on. This is because there’s still uncertainty surrounding this virus, and this half-life hasn’t been completely determined yet.
When all these strategies have been implemented, healthcare facilities can start thinking about decontaminating and sterilizing their PPE. If the supplies are still running short, following the CDC’s guidance for decontamination and reuse of FFPs might be necessary. This guidance isn’t definitive, and they recommend to listen to the manufacturer’s recommendations if they’re available.
3M N95 masks are some of the most popular types of respirators, particularly the 3M 8210 and 3M 8511 models. They’ve issued an update in April about how to decontaminate their N95 masks. These recommendations supersede the CDC guidelines.
The CDC establishes that a successful decontamination process must have the following requirements:
- Avoid damaging the filter media
- Avoid affecting the fit of the respirator
- Effectively inactivate the target organisms in the respirator
According to them, the three most promising potential methods for decontamination are ultraviolet germicidal irradiation, moist heat, and vaporous hydrogen peroxide. Although they’ve been tested extensively on respirators, they can be applied to any type of PPE. All these methods have to be evaluated and considered for each specific respirator model, always following the guidance of the manufacturer and third parties if needed.
- Ultraviolet germicidal irradiation: the exposure to ultraviolet exposure can decontaminate many masks simultaneously. You can set up an entire room with masks, and the UV lights can be set up around the room. Both sides of the mask need to be exposed to this light, and the monitors need to ensure that they’re delivering the proper dose. This is the fastest method among the three, and only about 15 minutes are required.
- Vaporous hydrogen peroxide: FFPs are gassed for 45 minutes with a sterilizant released from a specialized generator, which are already present in many hospitals because this decontamination method is used for MRSA. Over 50 cycles of success has been proven with this method, after that, the elastic straps showed degradation.
- Moist heat: multiple cycles under a temperature of about 65 to 80 degrees Celsius with a humidity of 50 to 85 percent can be more effective than exposure to ultraviolet light. This method is the hardest on the face masks of the three since they show a partial separation of the nosepiece foam from the mask.
After the respirators have been sterilized, a slightly different approach is needed for using PPE. Extra precaution and infection control is needed, including the following measures:
- Properly washing the hands before and after handling the respirator, be it to put it on, taking it off, or to adjust it.
- Avoid as much as possible to touch the inside of the respirator.
- When taking the respirator off, use clean gloves.
- Check the fit of the mask every time it’s going to be used.
- Check if there’s been any degradation to the straps, nose foam, or nose bridge before using it.