One of the activities that has changed the most since the start of the COVID-19 pandemic is work. Most of the country was forced indoors when the shelter-in-place was enacted, resulting in many people either losing their jobs or creating home offices. After several months, businesses are re-opening and implementing policies and procedures to prevent the transmission of COVID-19 among their employees and customers. The CDC recommends the use of respiratory protection and face coverings as infection control devices. There are several types of respiratory protection/face coverings available, with varying levels of effectiveness.
Surgical Masks: FDA Cleared; Large Droplet Protection
The use of surgical masks dates back to the early 1900’s when they were made of multiple layers of gauze and worn by hospital surgical teams as a means of preventing the contamination of open wounds. Modern surgical masks vary in their effectiveness for disease prevention. The standard surgical mask is cleared by the FDA. Surgical masks do not protect the wearer from inhaling small particles. The surgical mask does provide protection from large droplets, splashes, and body or other hazardous fluids. This mask is effective in protecting patients from healthcare providers’ respiratory emissions. Surgical masks do not provide a tight face seal, resulting in leakage when users inhale. When used in healthcare settings, they should be disposed of after each patient.
Respirators: From Hazards to Healthcare
The first respirators were also created in the early 1900’s, to protect those in hazardous positions, like miners, firefighters and soldiers. Healthcare providers began using them in the 1990’s. Today, there is the standard N95 respirator and the surgical N95 respirator. Both can be used as protection from small aerosol particles, as well as large droplets. Surgical N95 respirators are reserved for healthcare providers, in that they provide protection against airborne particles and hazardous fluids. When mandatory for the performance of an individual’s job, these devices must be fit tested to ensure a tight-fitting seal against the face. Some N95 masks are equipped with exhalation valves which makes breathing easier. These are not recommended for sterile environments, however.
Respirator effectiveness is measured by the percentage of particles being filtered, the amount of oil resistance and the APF (Assigned Protection Factor). For example, an N95 mask collects at least 95% of particles. The letter refers to the amount of resistance to oil aerosols, which reduces the filter’s effectiveness. An “N” type respirator offers no oil resistance; a respirator with the letter “R” is somewhat resistant to oils, and may be used for 8 hours in an industrial setting; “P” means the mask is strongly resistant to oils and has no time limits. An APF is the workplace level of respiratory protection that a respirator or class of respirators is expected to provide to employees…” (OSHA.gov, “Assigned Protection Factors for the Revised Respiratory Protection Standard,” February 2009) For example, N95 respirators have an APF of 10, which means only 1/10 of aerosols/particles in the air will be inhaled by the wearer. Respirators should be discarded after each patient, and when they become soiled, damaged or difficult to breathe in. NIOSH (National Institute of Occupational Safety and Health), an agency within the CDC, grants approvals for respirators.
NIOSH-approved Respirator Lists:
Elastomeric Respirators: Best Kept Secret
A third type of protection is the Elastomeric respirator, which is a NIOSH-approved, reusable device utilizing N95 filter cartridges. This respirator is constructed of synthetic or natural rubber material. Because the Elastomeric respirator is reusable, less money is spent over time, when compared to the costs associated with disposable respirators. It is roughly 10 times less expensive than N95 respirators. The Elastomeric is also a viable substitute when disposable masks are in low supply. It is easily disinfected with a bleach and water solution and has an APF of 10. A supply of replaceable parts must be stocked, such as inhalation/exhalation valves (and valve covers), filters, cartridges, canisters and straps. The Elastomeric is available in half or full facepiece versions. Full facepiece respirators cover the eyes, which is very important in preventing the spread of illness.
Elastomeric respirators with exhalation valves are not suitable for surgical environments. Any of the three filter types may be used with this device: N, R or P. A fit test must be passed when first adopted and every year thereafter. In a study at Allegheny Health Network, close to 2,000 healthcare workers were given Elastomeric respirators for one month. The results were very favorable. Users felt the mask was comfortable, and patients did not have adverse reactions. All workers chose to continue using the Elastomeric respirators, instead of returning to N95 respirators.
Powered Air Purified Respirators (PAPR): Highly Effective and Flexible
The Powered Air Purified Respirator (PAPR) is a battery-operated system which removes aerosols and droplets (as well as gases and vapors) from the air through filters, cartridges and canisters. There are three versions: full facepiece; loose-fitting hood/helmet; tight-fitting half-mask. The full facepiece has an APF of 1,000 and requires fit testing; tight-fitting units require fit testing and have an APF of 50; loose-fitting devices do not require fit testing and have an APF of 25. These devices are very effective, allowing only a minute percentage of airborne contaminates to reach the user. However, some of the drawbacks include the loud blower, limited field of vision, and higher initial costs.
Face Shields: From the Hospital to the Classroom
Face shields are made from rigid, clear plastic and cover the entire face, from the top of the forehead to beneath the chin. They protect the wearer from sprays of hazardous substances, such as coughs, sneezes or vomit. In some healthcare environments, face shields are worn along with N95 respirators. Face shields are wonderful options for teachers because students having the ability to see facial expression is a major key to learning.
Cloth Face Coverings: Wear These to Protect Others
Finally, there are the cloth facemasks, which became popular when the volume of available N95 respirators was limited. Many retailers are selling cloth masks with a plethora of stylish designs, making them appealing to large numbers of consumers. The jury is still out on their effectiveness, however. The CDC does not recommend cloth masks for children under 2 years old, or anyone who has trouble breathing, is unable to remove mask without assistance, or is unconscious or incapacitated. The CDC recommends that individuals wear cloth masks to prevent spreading the virus to others. The mask should cover the nose and mouth and fit snugly against the sides of the face. Cloth masks should be washed after each use.
There are many options for respiratory protection and face coverings, depending on the environment. It is important to keep in mind that a face covering, regardless of its effectiveness, is only one element of a prevention plan. The CDC maintains that people should continue practicing preventative habits, even while wearing a face covering, such as social distancing, regular hand washing (or using hand sanitizer when soap is not available), and avoiding sick people. As the economy struggles to re-open, it is crucial that everyone do their part in preventing the spread of this illness. A collective effort is required to see a substantial reduction in the number of COVID-19 cases.
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