I've done some research on elastomeric respirators due to the COVID pandemic and expected upcoming holiday travel.
Elastomeric respirators, such as half facepiece or full facepiece tight-fitting respirators where the facepieces are made of synthetic or natural rubber material, can be repeatedly used, cleaned, disinfected, stored, and re-used. They are available as alternatives to disposable half mask filtering facepiece respirators (FFRs), such as N95 FFRs, for augmenting the total supply of respirators available for use by HCP. While elastomeric respirators are not cleared by FDA for fluid resistance, based on their NIOSH approval, they can provide at least equivalent protection to N95 FFRs. Some types of elastomeric respirators can offer higher assigned protection factors (APFs) than N95 FFRs. They are equipped with replaceable filter cartridges or flexible, disc or pancake-style filters, which are not housed in a cartridge body. All elastomeric respirators equipped with the proper air-purification filters, cartridges, or canisters would also have utility in this application. Elastomerics may also have sealing surfaces and adjustable straps that accommodate a better fit.
While it is often possible to decontaminate the hard outer casing of filters, the filter material itself typically cannot be cleaned or disinfected for reuse. Instead, filter components should be discarded when they become damaged, soiled, or clogged.
Viruses and bacteria that cause acute respiratory infections can survive on respirator components for variable periods of time, from hours to weeks. Consequently, contaminated respirators must be handled, cleaned, and disinfected carefully and properly to reduce the possibility of the device carrying infection and contributing to disease transmission.2
Manufacturers typically recommend that filter cartridges be discarded after each use when cleaning an elastomeric respirator. Following manufacturer recommendations may be possible for some employers, but others may find discarding the filter component with each cleaning of an elastomeric respirator to be a cost factor when selecting between FFRs and elastomeric respirators, but especially in times of shortage, users may find it difficult to replace the filter cartridges due to supply difficulties. OSHA only requires replacing filters “where necessary,” for example, when soiled, contaminated, or clogged. Additionally, cleaning and disinfecting respirators can damage or deteriorate respirator facepiece component materials and adversely affect their performance when re-using after disinfection.
Generally, in industrial settings, filters are replaced when soiled or contaminated, damaged, and when breathing resistance increases. However, in healthcare settings breathing resistance will unlikely be a reason for filter replacement since filters should seldom if ever become loaded with heavy concentrations of dust. Depending on use, one manufacturer recommends the filter be discarded after each use, while another recommends the filter cartridge be disposed no later than 30 days after the first use if no oil mists are present.5 6 The respirator’s other elastomeric components should not be cleaned with solvents (e.g., acetone, ethanol) or exposed to temperatures greater than 50°C (122°F).
NOTE: P-series filters can generally be re-used until they are soiled, damaged, or difficult to breathe through. Caution should be used when using the filter for a live virus, and thorough disinfection of the filter cartridge should be completed.
Source: Elastomeric Respirators: Strategies During Conventional and Surge Demand Situations
An N95 FFR is a type of respirator which removes particles from the air that are breathed through it. These respirators filter out at least 95% of very small (0.3 micron) particles. N95 FFRs are capable of filtering out all types of particles, including bacteria and viruses.
Check to confirm that the product you are considering is certified as a respirator (such as an N95, FFP2, or KN95). Certified respirators contain filtration material capable of capturing particles, including ones that are too small to see with your eyes.
In the CDC’s questions and answers regarding personal protective equipment they state that “an N95 filtering facepiece respirator will protect you and provide source control to protect others. A NIOSH-approved N95 filtering facepiece respirator with an exhalation valve offers the same protection to the wearer as one that does not have a valve.
As source control, findings from NIOSH research suggest that, even without covering the valve, N95 respirators with exhalation valves provide the same or better source control than surgical masks, procedure masks, cloth masks, or fabric coverings.
The National Institute for Occupational Safety and Health has conducted research on valved N95 Filtering Facepiece Respirators (FFR) and found that “FFRs with an exhalation valve provide respiratory protection to the wearer and—according to the findings from this study—can also reduce particle emissions to levels similar to or better than those provided by surgical masks and unregulated barrier face coverings.”
For certain workplaces where exposure to COVID-19 cannot be controlled through administrative controls, physical distancing, barriers and ventilation employers may need to utilize personal protective equipment for this purpose. This includes “respirators (N95 filtering facepiece respirators or better, including elastomeric respirators, without exhalation valves or vents), face shields, protective gowns and gloves, to the workers at no cost.”
Source: Understanding Valved Filtering Facepiece Respirators in Non-Healthcare Workplaces