Fed OSHA’s COVID-19 ETS: What You Need to Know About Ventilation

By Conn Maciel Carey’s COVID-19 Task Force

Today’s topic on the Fed OSHA COVID-19 ETS is ventilation.


29 C.F.R. Section 1910.502(k) establishes ventilation requirements for covered facilities.  This summary describes the standard’s requirements for ventilation.

The ventilation provisions of the ETS do not require employers to purchase new HVAC systems or to reconfigure existing duct work to comply with the standard.  Rather, employers are required simply to increase indoor ventilation to the maximum extent possible on existing systems. New filtration equipment may be required, however, depending on the existing air filters in an HVAC system.

OSHA ventilation requirements are based on the concern that, without adequate ventilation, continued exhalation can cause the amount of infectious smaller droplets and particles produced by people with COVID-19 to become concentrated enough in the air to spread the virus to other people.  OSHA explained in the preamble that the more outdoor air the HVAC system is capable of drawing into the building, the greater the impact may be on limiting the potential for the virus to accumulate.

Accordingly, the ETS establishes five main requirements that employers who own or control buildings or structures with an existing heating, ventilation, and air conditioning (HVAC) system(s) must follow to comply with the ETS:

    • Verify that the HVAC systems are used in accordance with manufacturer instruction and design specifications and functioning as designed;
    • Maximize to the extent appropriate the amount of the outside air circulated throughout the HVAC system and number of air changes per hour;
    • Install MERV-13 or higher air filters if compatible with the existing HVAC system (*if the HVAC system is not compatible with such filters, filters with the highest compatible filtering efficiency for the existing system must be used);
    • Air filters must be maintained and replaced as necessary to ensure the proper function and performance of the HVAC system(s); and
    • All intake ports that provide outside air to the HVAC system(s) must be cleaned, maintained, and cleared of any debris that may affect the function and performance of the HVAC system(s).

The ETS does not require covered employers who do not own or control the buildings in which their services are provided to comply with the ventilation requirements of the standard.  Thus, employers that lease space in another employer’s building and have no authority over or responsibility for the HVAC system under the lease are not required to comply with these requirements.

The ETS states, however, that all employers should consider implementation of measures to increase and improve ventilation identified in CDC’s Ventilation in Buildings Guidance.  This Guidance includes multiple tools to improve ventilation, such as opening doors and windows as often as possible; using strategically placed fans to increase the effectiveness of open windows; setting the fan to “on” rather than “auto” on HVAC systems; using portable HEPA filtration systems to enhance air cleaning, etc.  As stated, though, implementation of the measures identified by the CDC is not mandated by the ETS; the CDC guidance is described as a recommendation to consider.

Please contact any of the OSHA attorneys in Conn Maciel Carey’s national OSHA Practice if you need help determining ETS requirements regarding ventilation.  Also, check out our articles about other sections of the ETS, including:

Look for another blog soon!

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