Surgical masks, homemade masks and respirators have become a symbol of the COVID-19 pandemic. Which is the right choice to use? How do they protect us?
An N95 mask is made from a material able to remove at least 95% of particles, mists, and droplets, including those that may carry viruses. When worn properly by individuals who have been medically approved, trained, and fitted for the mask, it provides protection from inhalation of such materials. Its effectiveness is dependent on its ability to form a seal on the face in order to prevent materials from entering through the sides of the mask. One size does not fit all, and there can be no facial hair that interferes with the seal of the mask.
N95 masks are in short supply and are only to be worn by individuals, including healthcare workers and emergency responders, who are in direct contact with ill patients. The shortage is so severe that many healthcare workers are reusing masks rather than disposing of them.
The Occupational Safety and Health Administration (OSHA) respiratory protection standard applies to employees wearing N95 masks. Per this standard, at least once each year an employee must complete training provided by Environmental Health and Safety (EHS), receive medical clearance by Occupational Health (OH), and have EHS or University Health Services (UHS) conduct a fit-test to ensure that the mask seals to the face properly.
Surgical masks are made from a material that traps or filters large particles and droplets. They do not seal to the face, so smaller particles and droplets can be inhaled.
Wearing a surgical mask helps reduce the amount of particles and droplets released into the air, especially from coughs and sneezes. They provide limited protection to the person wearing the mask.
In healthcare and emergency response, surgical masks are worn by sick patients to reduce exposure to the healthcare workers and emergency responders. Surgical masks are also in short supply and should not be used by the general public.
Cloth Face Coverings
Cloth face coverings do not filter or trap small particles and droplets and do not seal to the face. They can help reduce the spread of such particles outside of the mask. A cloth face covering may be a homemade mask made from fabric or household materials following one of many patterns available online or may be a scarf or bandana covering the nose and mouth.
Cloth face coverings provide little protection to the person wearing them, although they do help avoid touching the nose and face. The CDC recommends wearing a cloth face covering when in public, especially in situations where social distancing is challenging, to help prevent spread of the virus.
Other Respirators and Masks
There are several types of respirators and masks used for respiratory protection, each serving a specific purpose. A few examples:
- Nuisance Dust Masks – These are loose-fitting masks (do not create a seal between the user’s face and the device) made from materials intended to provide relief from nuisance dusts, such as common house dust, pollen, and grass. These are not medical masks.
- Powered Air Purifying Respirator (PAPR) – These can be loose or tight-fitting. The tight-fitting masks cover the entire face, including the eyes, nose, and mouth. The loose-fitting include a helmet and a hood that cover the entire head. They all have a motor that pushes contaminated air over a filter that cleans it, such that the user inhales filtered air. These can be used in healthcare as an alternative to an N95, and are more effective against COVID-19. They require disinfection after each use.
- Half-facepiece respirators – These are tight-fitting masks made of rubber or silicone with interchangeable cartridges that filter out different contaminants, based on the type of cartridge. Examples include particles like asbestos, chemical vapors, droplets and mists. HEPA (high efficiency particulate air) cartridges are effective for protection from COVID-19. However, these respirators are not comfortable for long-wear, need to be disinfected after each use, and require medical surveillance, fit-testing, and training.
- Full-facepiece respirators – These are tight-fitting masks that cover the eyes, nose and mouth. They work in the same way that a half-facepiece respirator functions, but are more protective since they cover more of the face. The same restrictions apply.
- Self-Contained Breathing Apparatus (SCBA) – These are tight-fitting full-face respirators that are attached to a tank of air or an air compressor. The air from the tank is pushed through the face of the mask to the user, providing the highest level of protection. These are impractical for protection against COVID-19.
- Surgical masks and N95 respirators are in short supply and are needed to protect the nation’s healthcare workers. CDC and NJ DOH currently do not advise the use of either by the general public.
- Other types of masks might provide protection from Covid-19, but require fit-testing, training, medical clearance, and frequent disinfection. Most are impractical for daily use.
- Cloth face coverings made from household items or fabrics can help reduce the spread of Covid-19, especially during times when social distancing is challenging.
For More Information
- Recommendation Regarding the Use of Cloth Face Coverings, Especially in Areas of Significant Community-Based Transmission – US Centers for Disease Control
- Use of Cloth Face Coverings to Help Slow the Spread of Covid-19 – US Centers for Disease Control. Includes instructions for how to make cloth face coverings from fabric and household materials.
- Cloth Face Covers: Questions and Answers – US Centers for Disease Control
- Respirator Fact Sheet – National Institute of Occupational Safety and Health. References SARS, but information is also useful for Covid-19.
- Respirator Use – Princeton University Environmental Health and Safety