What Does the “Six-Foot Rule” Really Mean?

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TAG has received questions on the “six-foot” social distancing rule, including how it relates to defining a “close contact” in business for the purpose of requiring self-quarantining and the underlying scientific evidence.

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Coupled with the everchanging science and varying recommendations from health authorities, there are various estimates for social distancing, close contacts, and the six-foot rule. As of the beginning of April:

• CDC considers a “close contact” as a person who has been within six feet “for a prolonged period of time,” describing that time as ranging from 10 to 30 minutes or more. (For CDC’s most current information, see its Public Health Recommendations for Community-Related Exposure.) 

• Europe’s CDC (ECDC) defines “close contact” as face-to-face contact with a COVID-19 case within six feet and more than 15 minutes. But, it adds, the 15-minute limit is arbitrarily selected for practical purposes; more prolonged duration of contact increases the risk of transmission.

• As a qualitative measure, each individual exposure should be considered based on the conditions under which it occurred, and TAG recommends thinking about a 15-minute timeframe as a general qualitative measure of exposure – not an absolute maximum or minimum exposure limit. There may be an example of close contact exposures where less than 10 minutes may represent significant risk, especially if social distancing isn’t practiced. There may be other situations where prolonged exposures of more than 15 minutes represent low-risk exposures. This can happen if social distancing is adequate and other underlying programs such as active employee wellness checks, good hygiene practices, regular cleaning and disinfection of common areas, and proper PPE are also used. 

• TAG has found that each situation is unique. If a company is uncertain about who may be a “close contact”, they should reach out for outside assistance. 

 

While CDC’s “close contact” time range is extensive, research has demonstrated that infection within 10 minutes is possible. As seen in CDC’s March 6th MMWR, 104 (23%) of 445 individuals identified as a “close contact” of the first 10 travel-related U.S. confirmed COVID-19 patients had spent at least 10 minutes within 6 feet of a patient with confirmed disease – suggesting that infection can occur within 10 minutes.

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Because the science of COVID-19 transmission is still undergoing, it is essential to use timeframes as general guidance. Other factors must be considered, too, including:

• Proximity and the duration of exposure can both impact transmission (e.g., longer exposure time and/or closer proximity likely increases exposure risk).

• The symptoms and type of interaction can increase risk (e.g., if the person coughed directly into the face of the individual).

• If there is widespread mask usage in the facility or area; mask usage can reduce the risk of droplet transmission. 

 

Other high-risk contact situations include:

• Living in the same household.

• Having direct physical contact (e.g. shaking hands) or unprotected direct contact with their infectious secretions (e.g. coughed on, touched used Kleenex, etc.)

• Being a healthcare worker (HCW) or other person providing direct care without proper PPE.

 

With all this, TAG’s advice is to consider close contacts at work to be those with whom you work closely,  or are within six feet of during meals or breaks. Those that you pass in the hallway even numerous times, during a shift, may not necessarily count.