Coronaviruses have been found in a diverse array of bat and bird species that seem to act as natural hosts. Molecular clock dating analyses of coronaviruses suggest that the most recent common ancestor of these viruses existed around 10,000 years ago. Now fast forward to late 2019: The world learned about the COVID-19 virus shortly after a cluster of severe pneumonia cases were reported on New Year’s Eve in the city of Wuhan, China. From there, COVID-19 developed into a worldwide pandemic. It has had a major impact worldwide on all areas of life. 

Most definitely included in this impact have been schools. In less than a year, the pandemic brought about new types of instructional modalities, including hybrid and virtual learning, and a new school community featuring Zoom meetings, socially-distanced classrooms, and students wearing masks, stuck in their seats, harkening to the sterile classroom environment of a foregone compliance-based educational system.

At this time, many schools across the country are planning to have students return to face-to-face, on-site instruction. This commentary will review current updates in students/teacher safety protocols for science/STEM laboratory work.

The Centers for Disease Control (CDC) has had a number of changes in recommendations for school instruction, resulting from scientific research findings over the last year. The following is an updated list of the most recent safety protocols to help protect students and teachers actively working in school science and STEM laboratories.

• Wash hands regularly using soap and water (preferred) or hand sanitizer. (Be careful when using hand sanitizers. The Food and Drug Administration (FDA) has listed more than 230 hand sanitizers that are dangerous and should not be used. For a complete list, see https://www.fda.gov/drugs/drug-safety-and-availability/fda-updates-hand-sanitizers-consumers-should-not-use#products. Do not bring in your own sanitizer from home. Hand sanitizers that are used on campus should be board-approved, and the Safety Data Sheet (SDS) should be on file.)
• Minimize sharing of equipment, materials, and other items. Always wash your hands before and after use.
• Clean common surfaces at the end of the hands-on activity: e.g., table tops, equipment, etc.
• Maintain an appropriate social distance from others at all times.
• Wear a cloth mask or disposal surgical face mask and other appropriate personal protective equipment (PPE) according to the manufacturer’s instructions.
• Follow the manufacturer’s instructions on how to properly use sanitizers/disinfectants provided if required for use.

What are the current recommendations for cleaning common surfaces in science and STEM laboratories? The following is a basic list of considerations.

• Clean surfaces as directed by the manufacturer’s instructions. The current science research has shown that people can get infected via contaminated surfaces, but the risk is low. The CDC notes that regular cleaning of these surfaces with soap or detergent works. Disinfection is not normally necessary. If you are compelled to disinfect a surface, only do so after cleaning it first.
• Disposable paper towels or other wipes may be placed into the regular trash.
• Equipment and laboratory stations shared by multiple people or lab groups should be cleaned after each use as per usual lab safety protocols using soap and water, unless other cleaning protocols are suggested by the manufacturer.
• After removing hand PPE, wash hands and forearms thoroughly for at least 20 seconds with soap and warm water.
• Cleaning with soap and water, followed by disinfection of surfaces, is only recommended in indoor settings like schools where there has been a suspected or confirmed case of COVID-19 within the last 24 hours.
• As we have learned more about the coronavirus, protocols have been amended. Both the CDC and the Environmental Protection Agency (EPA) have issued guidelines that are now in mutual agreement. The EPA will stop expediting requests to approve disinfectants, as there is a low risk of transmitting the coronavirus through surface contact. (See https://content.govdelivery.com/accounts/USAEPAOPPT/bulletins/2d5b5f3.) Disinfectants should only be used as needed, as their overuse, or errant use, can do more harm than good. (See https://www.epa.gov/sites/production/files/2021-04/documents/cleaning-disinfecting-one-pager.pdf.)

When considering cleaning delicate surfaces or electronics, the following are basic procedures that should be used.

• Make sure to power off all devices. Unplug all external cables, cords, devices, and power sources.
• Always wear the recommended PPE according to the manufacturer’s instructions.
• Avoid spraying soap and water or disinfectants directly onto surfaces and potentially getting liquid into equipment openings. Follow the manufacturer’s instructions for cleaning equipment.
• Use only cleaning agents as provided by your local board of education. Make sure that you have appropriate SDS for the cleaner on file.
• For delicate surfaces, such as computers, electronics, instruments, keyboards, microscopes, screens and tablets, and equipment, use a paper towel or cloth with soap and water. Follow the manufacturer’s instructions for cleaning equipment.
• Gently wipe the surface until it is visibly wet. Allow it to evaporate.
• Computers, tablets, and keyboards that are shared should be cleaned with soap and water or sanitizer under the same conditions as noted above in the section titled Cleaning Common Surfaces. Follow the manufacturer’s instructions for cleaning equipment.
• Wash hands and forearms thoroughly for at least 20 seconds with soap and warm water after removing PPE.

Finally, when cleaning PPE, the following two-step protocol should be adopted.

1. Wash goggles and/or glasses with antibacterial soap and warm water.
2. After washing and drying, place them in the goggle sanitizer with UV-C bulbs, and your teachers will run the sanitizer for the amount of time recommended by the sanitizer manufacturer.

Early in April, the CDC released the latest recommendations on when and how to use disinfectants. (See https://www.cdc.gov/coronavirus/2019-ncov/community/disinfecting-building-facility.html.)

As previously noted, cleaning simply by using soap or detergent as cleaning agents helps to reduce germs on surfaces. These cleaning agents can remove the contaminants and also may weaken or damage some of the virus particles, therefore decreasing the risk of infection from surfaces. When no people with confirmed or suspected COVID-19 are known to have been in a space, cleaning once a day is usually enough to sufficiently remove the virus that may be on surfaces and help maintain a healthy facility.

Disinfecting by using EPA’s List N products (see https://www.epa.gov/sites/production/files/2020-06/documents/sars-cov2_listn_06122020.pdf) will kill any remaining germs on surfaces. This further reduces any risk of spreading infection. Disinfectants should be used only after general cleaning has been first completed. The CDC recommends either cleaning more frequently or disinfecting (in addition to cleaning) in shared spaces under certain conditions, including the following:

• High transmission of COVID-19 in your community;
• Low number of people wearing masks;
• Infrequent hand hygiene; 
• the space is occupied by certain populations, such as people at increased risk for severe illness from COVID-19; or
• if a sick person or someone who tested positive for COVID-19 has been in your facility within the last 24 hours, you should clean and disinfect the space.

Again, teachers should check this CDC website (https://www.cdc.gov/coronavirus/2019-ncov/community/disinfecting-building-facility.html) for specifics on how and when to disinfect laboratory surfaces, equipment, etc. 

With the advent of increased access and use of vaccinations in the population, along with additional research, the following protocols are recommended by the CDC.

• For all laboratory/classroom occupants at the middle and high school levels, students should be at least 3 feet apart in areas of low, moderate, or substantial community transmission. In areas of high community transmission, middle and high school students should be 6 feet apart, if cohorting is not possible.
• Maintain 6 feet of distance in the following settings: Between adults in the school building (teachers and staff), and between adults and students. 
• Given use of cohorts at the elementary level, social distancing may be reduced to at least 3 feet between students, but make sure face masks are worn.
• Recent research, which is still undergoing the peer review process, suggests that social distancing provides a false sense of security. Other factors, such as the size of the room, how many people are in the room (related to social distancing), what the room is used for, and the ventilation in the room are more important factors affecting the spread of the coronavirus. The study does not state that you should forgo social distancing and stand next to others in enclosed spaces; it just states that it is less important than other factors (see https://www.pnas.org/content/118/17/e2018995118). Remember that the study has not been thoroughly vetted as of the publication of this blog post. More details will follow at a later date.
   

Being vaccinated is an excellent layer of protection against the coronavirus. However, vaccinations only make you safer. If you are vaccinated, you still need to remain masked and follow social distancing protocols in your school. For more information, consult these links:

• https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fcommunity%2Fschools-childcare%2Fcloth-face-cover.html
• https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated.html. 

On April 27, the CDC relaxed mask guidelines for vaccinated individuals who are outdoors or with family members in enclosed spaces (see https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated-guidance.html). Despite these changes, masks should still be worn in schools. Depending on your state and local school board, you may still have to wear masks on campus while outdoors. Check with your building’s principal for more information. The CDC is continually monitoring the situation and updating its website. Please periodically check their website for accurate and complete information.

Over time, with the advent of additional science research and applications for reducing or ending the COVID-19 pandemic, there will be a continued evolution, and in some cases, revolutionary changes on how to deal with the COVID-19 virus through safety protocols. Teachers and administrators need to check the CDC’s and other websites regularly to address these changes. Hopefully the end will be in sight sooner than later!

One final note—Cleaning up after laboratory work has always been the standard safety protocol; nothing new! Remember that chemical and biological hazards (flu virus, bacteria, etc.) exist to which students and teachers may be exposed. In this way, using the original COVID-19 safety protocols for cleaning, sanitizing, and disinfecting also helps to lower risk of exposure to all of these hazards.  

For additional updated CDC protocols, see Operating Schools During COVID-19: CDC’s Considerations: https://www.cdc.gov/coronavirus/2019-ncov/community/schools-childcare/

Submit questions regarding safety to Ken Roy at safersci@gmail.com or leave him a comment below. Follow Ken Roy on Twitter: @drroysafersci.

Safety Blog Acknowledgement: NSTA Chief Safety Blogger Dr. Ken Roy wishes to sincerely thank nationally recognized District Supervisor of Science Kevin S. Doyle, Ed. D., Morris Hills Regional District, Rockaway, New Jersey (kdoyle@mhrd.org) for his professional review of and contributions to this commentary.