From the Guidelines
The current guidelines for wearing masks to prevent COVID-19 transmission recommend using well-fitting masks in crowded indoor settings, on public transportation, in healthcare facilities, and when you're sick or caring for someone with COVID-19, as supported by the most recent evidence from 2021 1.
Key Recommendations
- Medical-grade masks like N95, KN95, or surgical masks provide better protection than cloth masks, and should be used in healthcare settings or when interacting with someone who has COVID-19.
- The mask should completely cover your nose and mouth with a snug fit against the sides of your face.
- Disposable masks should be discarded after use in high-risk settings or when visibly soiled, while reusable masks should be washed regularly.
- Proper mask wearing includes washing hands before putting on and after removing the mask, touching only the ear loops or ties, and avoiding touching the front of the mask.
Rationale
Masks work by creating a physical barrier that blocks respiratory droplets and aerosols containing the virus from being inhaled or exhaled. They are most effective when combined with other preventive measures like vaccination, good ventilation, physical distancing, and hand hygiene.
Special Considerations
People with certain medical conditions or young children under 2 years may have exemptions from mask wearing, as noted in various guidelines 1.
Evidence-Based Practice
The use of masks, particularly in conjunction with hand hygiene, has been strongly recommended for the prevention of viral transmission, including COVID-19, based on a systematic review of nonpharmacological interventions 1.
From the Research
Mask Guidelines for COVID-19 Prevention
The guidelines for wearing masks to prevent COVID-19 transmission are as follows:
- Always wear a face mask or respirator in indoor public settings to reduce the risk of acquiring SARS-CoV-2 infection 2
- Perform hand hygiene frequently with an alcohol-based hand rub or with soap and water if hands are dirty, regardless of the type of mask used 3
- Use a well-fitting face mask or respirator that filters virus-sized particles, such as N95/KN95 respirators or surgical masks 2, 4
Types of Masks and Their Effectiveness
- N95/KN95 respirators offer the highest level of personal protection against acquiring infection 2, 4
- Surgical masks are also effective in reducing transmission of infection, but may not provide the same level of protection as N95/KN95 respirators 2, 4
- Cloth masks may not be as effective as N95/KN95 respirators or surgical masks in reducing transmission of infection 5
Adverse Effects of Mask Wear
- Healthcare workers may experience adverse effects such as headaches, respiratory distress, facial irritation, and pressure-related injuries when wearing respirators compared to surgical masks 6
- Effective mitigation strategies are important to ensure the uptake and correct use of respirators by healthcare workers 6
Special Considerations
- Airborne precautions, including goggles and respiratory protection with the use of an N95 or equivalent mask respirator, may be necessary during aerosol generating procedures to prevent airborne transmission 3
- Keeping a distance and wearing medical masks and eye protection during close contact can efficiently protect against respiratory diseases transmitted via droplets 3