Skip to main content
King County Courthouse Third Avenue entrance closed until January 1, 2020. Please use alternative routes.  
King County logo

This guidance is intended to assist employers, including governments, businesses, community-based organizations and others in developing policies to decrease transmission of influenza in workplace settings. During an influenza pandemic, additional guidance specific to the pandemic virus may be provided by Public Health to health care providers, government agencies, private businesses, and the general public.

Overview

In the event of a pandemic, employees serving at work will seek guidance about the effectiveness of masks* in protecting them from getting influenza from colleagues or members of the public, including if masks will be made available to them in order to conduct their work.

Based on existing scientific knowledge, it is not known if mask use would provide protection from influenza infection for general use in the population. Over-reliance on masks could hinder the use of strategies believed to be more effective in stopping disease transmission. Further, mask availability is almost certain to be limited during an influenza pandemic, and supplies will need to be prioritized for situations where their use would be most effective.

Interim mask recommendation

Public Health recommends mask use** for all persons symptomatic with influenza and for home care givers of influenza patients as one part of a comprehensive infection control approach to prevent influenza transmission. In some circumstances, it is also reasonable for employers to consider masks for use in the workplace.

Rationale

In order to contain infectious droplets from persons with symptoms of influenza from spreading to others, symptomatic (ill) persons should wear a mask when they must go out in public and when contact with others is unavoidable. This would include when an ill person is receiving medical care in a facility and when an ill person is in close contact with others in the home. Employers may consider having a supply of masks at work available for employees who become sick during the work day, providing them with a mask as they leave the workplace.

Masks are used by healthcare workers to protect the wearer's mucous membranes of the nose and mouth from contamination by infectious droplets from someone with influenza. Although the effectiveness of mask use is not known in the home care setting, masks may also be of benefit for persons caring for ill family members in the home (both for themselves and to put on their sick family members) during close contact (within 3 feet). Employers may choose to purchase masks for employees as part of a home preparedness kit in the event that they or a family member becomes ill.

The effectiveness of mask use in the workplace is not known. However, during a severe pandemic, it is reasonable for employers to consider mask use for workers who, as part of their job, come in close contact with large numbers of persons on a regular basis, and for whom alternative workplace infection control measures are not available. Examples of people who fall into this category include bus drivers, clerks, and police officers. When possible, it is preferable to modify the work environment to eliminate close contact with symptomatic people, which will eliminate the need for masks and provide better protection. For example, retail stores and banks may be able to restructure how people enter the facility, where they stand, and how many workers come in close contact with them.

Prevention of influenza transmission primarily requires strict attention to hand hygiene as the main protective measure, as well as adherence to other recommended measures such as environmental cleaning and social distancing. Employers should reinforce and support these messages and behaviors with their employees through strategies such as making alcohol-based hand gel and tissues, along with convenient waste disposal container, widely available, sending people home who exhibit symptoms or become ill, and creating policies that do not penalize workers for not coming to work when ill.

Using masks in one situation will not be an effective preventive measure if exposure to influenza occurs outside of that setting. If masks are worn during certain situations, they should be worn at all times in that situation for the duration of the outbreak.

* In this document, the term masks refers to medical masks, not respirators.

Medical masks, also called surgical (which have ties or a single elastic band) or procedure masks (with ear loops) are designed to prevent the wearer from spreading germs to others through sneezing and coughing and to protect the wearer’s mucous membranes of the nose and mouth against infections spread by large respiratory droplets, generated by actions such as coughing, sneezing and talking.. This is the way influenza viruses primarily spread.

Respirators often look like medical masks, and are used primarily in health care facilities. They are designed to protect the wearer from inhaling very small particles. Some respirators are made for single use and some are reusable, with filter cartridges that must be replaced periodically. Respirators are used in the medical setting to protect health care providers from airborne germs. Each individual must undergo a procedure called fit testing to be certain the respirator will be effective. Respirators labeled as “NIOSH-certified” N95, N99 or N100 protect against very small particles, although no respirator can ever guarantee full protection. Respirators are recommended for health care workers during certain high-risk settings and procedures.

**Any time masks are used, it is important that:

  • They should be changed when they become moist.
  • Masks should not be left dangling around the neck.
  • Upon touching or discarding a used mask, hands should be washed or a hand sanitizer used.

Frequently Asked Questions

  1. Should employers consider purchasing a supply of masks now for employees?
    YES.
     – For the following purposes during an influenza pandemic:
    • employees who become ill at work
    • part of an employee’s emergency home supplies kit
    • employees having frequent contact with large numbers of people at work for whom modification of the work environment to minimize close contact with others is not feasible

  2. Should masks be used at work by all staff regardless of their work environment?
    NO. 
    Masks may be part of a comprehensive infection control strategy for workers who, as part of their job, have frequent contact with large numbers of people, and for whom alternative workplace infection control measures are not available.

  3. Are masks a primary component of an infection control system for employers, employees, individuals and families?
    NO. 
    We do not know if mask use will be effective for general use by the public. The most important ways to avoid influenza infection for employers, employees, individuals and families are:
    • Minimize exposure to other people as much as possible and stay away from ill people
    • Stay at home and away from others when ill
    • Wash hands frequently and avoid touching your nose mouth and face unless you’ve just washed hands.
    • Always cover your cough

  4. How often should I change masks, and how should they be handled and disposed?
    When using surgical or procedure masks:
    • Change masks when they become moist
    • Do not leave masks dangling around the neck
    • Upon touching or discarding a used mask, wash hands or use alcohol sanitizer
    • Dispose of used masks with other routine waste