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CDC Guidelines for Reopening K-12 Schools 2021

Understand what the new CDC guidelines for reopening schools means for your or your child's school and why an IAQ focus is important.

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cdc guidelines for reopening schools

Schools have been in the limelight since the beginning of the pandemic. Debates about in-person vs. remote instruction have seemingly been ongoing for the entirety of COVID-19. And that’s for every kind of educational and childcare setting. As the Fall 2020 semester came and went with a majority of schools conducting remote classes or hybrid instruction, interest shifted to 2021 and what classroom settings would look like in the new year. Parents, teachers and faculty, facility managers and school administrators alike waited in anticipation for official guidelines from the Centers for Disease Control and Prevention (CDC) on reopening plans. Suggestions were finally released in February, but what do the CDC guidelines for reopening schools actually recommend? 

The CDC states to prioritize schools for reopening and remaining open during the pandemic. It is the organization’s opinion that schools are crucial to a child’s educational and emotional progress. In order to return to in-person instruction–schools need to create safe, healthy and clean classrooms and spaces. And a focus on indoor air quality is critical to create that healthy environment.  

CDC Recommendations for Schools Reopening During the COVID-19 Pandemic

The CDC released its K-12 schools operational strategy guidelines on Feb. 12, 2021. The guidance’s purpose is to provide schools with clear steps and suggestions to both reopen and remain open during the pandemic. The main takeaway? K-12 schools can open and stay open for in-person learning if schools strictly implement layered prevention strategies.

Layered prevention simply means utilizing multiple mitigation methods at once. The idea is that layered prevention = transmission prevention in schools. The guidance lists five main suggestions:

  • Universal and correct use of masks
  • Physical distancing 
  • Routine hand washing and respiratory etiquette 
  • Cleaning and maintaining healthy facilities 
  • Contact tracing with isolation and quarantine 

The CDC’s position is to prioritize the first two suggestions in schools–universal mask use and physical distancing. Additional suggestions include monitoring community transmission, controlling case clusters (defined as any number of cases above two), organized COVID-19 testing and prioritized vaccinations for school staff. Initial public reactions to the CDC guidelines were varied. Many schools viewed the 6 feet physical distancing recommendation as a barrier to opening. And IAQ and HVAC experts in particular were disappointed by the lack of focused communication on indoor air quality solutions. 

CDC Revises Operational Guidelines

Then, roughly a month after the initial release, the CDC updated its official guidelines. The March revisions reduced the physical distancing recommendation from 6 feet to 3 feet in certain circumstances and placed a greater emphasis on ventilation in school buildings. The 3 feet change is notable. It allows more schools to open for in-person instruction because more students can fit in the classroom. School districts across the country felt that the change provided more flexibility and opportunity to reopen school buildings. 

However, this shift makes indoor air quality even more significant. New risks include: higher classroom occupancy, periods when masks aren’t possible like lunchtime and overall difficulties with universal mask wearing. These factors make IAQ a necessary prevention strategy. 

As more and more schools across the country set reopenings dates and/or promise in-person instruction in the fall, let’s take a closer look at the IAQ takeaways from the CDC guidelines for reopening schools.  

Cleaning and Maintaining Healthy Facilities

The hard truth about our surrounding environment impacting health and wellness means that how we care for the built environment truly impacts us. This is why as IAQ experts, we view cleaning and maintaining healthy facilities as a crucial CDC guideline to implement. The healthy facility suggestion is to: make changes to the physical space to ensure a healthy indoor environment through ventilation and regularly cleaning high-touch surfaces. Other CDC pages and resources provide more in-depth information about how to implement increased building ventilation in schools and childcare facilities. 

1. Bring in as much outdoor air as possible

…by opening windows and doors when possible.

IAQ.Works Tip: Relying on natural ventilation alone is not the only option–or the best option! Weather, outdoor air quality and window locations in the classroom are all factors that hinder natural ventilation. Whole-building ventilation systems such as ERVs and HRVs offer improved ventilation rates and increase the amount of fresh air indoors. They also install directly into the building’s HVAC system. Mechanical ventilation is the better option. 

2. Ensure building HVAC settings maximize ventilation

… according to ASHRAE 62.1. Increase HVAC system total airflow and minimize air recirculation. Building HVAC systems should be serviced regularly and meet code.

IAQ.Works Translation: ASHRAE 62.1 and 62.2 (AKA the American Society of Heating, Refrigerating and Air-Conditioning Engineers) are the recognized building ventilation standards. These are the minimum indoor ventilation rates. Maximizing ventilation is when the HVAC system is bringing in as much outdoor air as possible, reducing the need to rely on air recirculation. Recirculation is often used to save money and keep indoor temperatures comfortable. The CDC suggestions say to prioritize ventilation rates instead. They also suggest running the HVAC system before school and after school. 

3. Filter and/or clean indoor air by improving filtration level

IAQ.Works Translation: The highest level air filters can actually be too good. (It sounds strange, we know.) But the best air filters can actually choke an HVAC system’s airflow. Thus, the best filter depends on the specific HVAC system. And the best school building air filter is the highest filter level possible that does not reduce airflow. Air filters also need to be sized correctly and checked or replaced routinely. Cleaning indoor air is air purification. This is possible with either a whole-building purification system or portable HEPA filter air cleaners.

4. Use the exhaust fans in restrooms and kitchens

IAQ.Works Translation: This type of ventilation is known as spot ventilation. It’s using the localized exhaust fans to ventilate a smaller targeted space–such as the bathroom or kitchen. These fans should be on and running at full capacity the entire time students and staff are in the building.  

5. Open windows in buses and other school transportation methods

All of these solutions help reduce the number of indoor air pollutants and concentration of particles in the air–including virus particles! This is why improving ventilation and indoor air quality in school settings is necessary. It helps reduce the spread of infection and germs indoors. 

Indoor Air Quality Perspective

According to a recent poll, 69% of parents are somewhat concerned and 42% are very worried about their child’s potential learning setbacks because of the pandemic. And yet, 64% also say they are somewhat concerned and 33% are very worried about increased infection from in-person learning. Many parents are conflicted about the benefits vs. risks of returning to school. 

Layered prevention means the safest school building is one that utilizes multiple strategies. As in–a focus on IAQ in addition to masks and physical distancing. Indoor air quality upgrades and solutions can help create a safer and healthier indoor environment. Make sure your school, your child’s school or even your local community’s schools are pursuing IAQ solutions and doing everything they can to improve ventilation in school buildings. Supplementing masks and distancing with indoor air quality upgrades will wildly benefit the classroom setting and hopefully aid your peace of mind. 

K-12 Schools in 2021 

The CDC’s guidelines for reopening schools continuously emphasize the importance of layering several suggested mitigation strategies. Schools need to use preventative actions in combination. From an IAQ approach, we know that indoor air quality solutions will help keep students and teachers safe in school settings. 

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