The way to Reopen Workplaces Safely

Many American offices have been virtually empty for the past 15 months. Conference rooms and booths remained unused, elevators not called, files untouched. Whiteboards became time capsules. Succulents had to take care of themselves.

However, many of these jobs will slowly come back to life in the coming weeks. According to a recent poll by the Partnership for New York City, around half of the million office workers in Manhattan are expected to return to their desks at least part-time by September.

Although the risk of contracting Covid-19 in the United States – especially those who are fully vaccinated – has decreased significantly, it has not gone completely and many workers remain nervous about going back to their desks. (Many others, of course, never had the luxury of working remotely.)

“If you’re still feeling uncomfortable or anxious, that’s totally understandable,” said Joseph Allen, a healthy building expert who teaches at Harvard TH Chan School of Public Health. “This pandemic has had a profound impact on all of us, and people will be ready to get back into life or interact with people again at other times.”

But scientists have learned a lot about the virus over the past year, and there are some clear, evidence-based steps employers can take to protect their workers – and workers can take to protect themselves. Some of these strategies are likely to pay dividends that will last out of the current crisis.

“I think it’s important for us as a community, but also for individual employers, to think about these questions for more than just this week and this month,” said Alex Huffman, an aerosol scientist at the University of Denver. “How do we make decisions now that will also benefit the safety and health of our workplaces in the future?”

Although Covid-19 is the number one health problem, long-term building closures can pose their own risks. For example, unused sanitary systems can be colonized by Legionella pneumophila, bacteria that can cause a type of pneumonia known as Legionnaires’ disease.

“Long periods of standing, lukewarm water in pipes – the exact conditions in many understaffed buildings currently – create ideal conditions for Legionella to grow,” said Dr. Everyone.

Some schools have already reported that they found the bacteria in their water. In buildings with lead pipes or fittings, high amounts of the toxic metal can also accumulate in standing water. Employers can reduce both risks by flushing their faucets thoroughly or turning the water on and running before opening it again.

“We know that flushing water during periods of inactivity usually reduces lead levels and also reduces potential bacteria that can build up,” said Jennifer Hoponick Redmon, senior environmental health scientist at RTI International, a North Carolina-based nonprofit research organization. She added, “A general rule of thumb is 15 minutes to an hour of flushing for long-term closings, such as for Covid-19.”

The Centers for Disease Control and Prevention also recommend companies test for mold and pest infestation before reopening.

Since the coronavirus is believed to spread primarily through tiny airborne droplets, employers should upgrade their ventilation and filtration systems before bringing workers back, experts said.

“One thing you can do before going back to work is just ask them what they did,” said Dr. Everyone. “And when you hear things like, ‘Yes, we hit code,’ it is an indication that something is wrong. They should exceed the minimum ventilation and filtration rates. “

In general, while the ideal rate of ventilation varies, employers should maximize the amount of fresh air that gets in from the outside, he said. In a relatively small room – about the size of a typical school classroom – employers should aim for four to six air changes per hour, which means that the air in the room is completely renewed every 10 to 15 minutes. Opening windows can also improve airflow.

Good quality air filters, such as those rated MERV 13 or higher, can trap a majority of the virus particles in the air. Some commercial buildings are not equipped for these high-performance filters; In these offices, portable air purifiers equipped with HEPA filters can be effective, experts said.


June 11, 2021 at 11:34 a.m. ET

“These types of portable units are great at removing particles from space,” said Dr. Huffman. “And the next level is even a desktop-level HEPA filter where you have a really small unit that delivers clean air into your direct breathing zone.”

These personal units can be particularly useful in poorly ventilated offices, although experts stressed that it is employers, not employees, that should be responsible for improving indoor air quality.

While ventilation and filtration are critical, employers and property managers should stay away from fog machines, fumigators, ionizers, ozone generators, or any other “air purifying device” that promises to neutralize the coronavirus by adding chemical disinfectants to the air. “These are all really terrible ideas about what to do with indoor air,” said Delphine Farmer, an atmospheric chemist at Colorado State University.

The compounds these products emit – which can include hydrogen peroxide, bleach-like solutions, or ozone – can be toxic, inflame the lungs, cause asthma attacks, and lead to other types of respiratory or cardiovascular problems. And there’s no rigorous, real-world evidence that these devices actually reduce disease transmission, said Dr. Farmer.

“A lot of employers now think – and school districts and property managers – think that using these devices has solved the problem,” said Dr. Farmer. “So then they don’t increase the ventilation rates or add other filters. And that means that people think they are safer than they actually are. “

Surfaces pose a minimal risk of coronavirus transmission, and unnecessarily applied disinfectants can also get into the air and be toxic if inhaled. In most normal workplaces, wiping the desk with bleach is likely to do more harm than good, said Dr. Farmer. (Some specific workplaces – such as hospitals, laboratories, or commercial kitchens – may still require disinfection, according to experts.)

There is also no particular need for special antimicrobial wipes or detergents that can encourage the emergence of antibiotic-resistant bacteria and wipe out communities of benign or beneficial microbes. “As tempting as it is to try to sterilize everything, it will never happen and it can have serious consequences,” said Erica Hartmann, an environmental microbiologist at Northwestern University.

In the first few months of the pandemic, plastic barriers emerged in schools, shops, restaurants, offices, and other common areas. “They can be great for stopping the bigger droplets – they’re really big sneezers,” said Dr. Huffman.

But the smallest and lightest particles can simply float above and around them. These barriers “may not offer enough advantages to justify their costs,” said Martin Bazant, a chemical engineer at the Massachusetts Institute of Technology. They can even increase the risk of disease transmission by encouraging riskier behavior or obstructing airflow.

There are some environments where these types of barriers can still be useful. “It can be a really good idea for people who otherwise have very close personal contact, such as grocery store clerks,” said Dr. Farmer. “But beyond that, in offices where you sit for a long time, there is no advantage in being in a plexiglass cage.”

Social distancing can still have some benefits; When an employee exhales infectious viruses, people sitting directly in that person’s breathing zone are likely to be exposed to the highest doses. “If you are sitting at a common table half a meter away from someone, there could be potential value in moving a little further away,” said Dr. Huffman.

But aerosols can stay in the air for hours and travel well over six feet, so moving desks further apart is likely to have diminishing returns. “Strict distancing orders like the six-foot rule protect little against long-distance aerial transmissions,” said Dr. Bazant, “and can convey a false sense of security in poorly ventilated rooms.”

In offices where most people are vaccinated and local case numbers are low, the benefits of distancing are likely to be minimal, scientists said. At higher risk workplaces, de-compression should be considered or the number of people present at the same time – any of whom could be infectious – should be reduced. “For me, that was the biggest benefit of this indoor social distancing,” said Dr. Farmer. “There are just fewer potential sources of SARS-CoV-2 in a room.”

Companies could allow a subset of employees to work from home indefinitely or on alternate days or weeks. You could also consider “cohorting” or creating separate teams of employees who do not have face-to-face interactions with those who are not on their team.

Forming such cohorts could also facilitate the response if someone becomes infected with the virus, so that the affected team can be quarantined without having to shut down an entire workplace. “When thinking about reopening, do we have to think about what to do when we inevitably see a case?” said Justin Lessler, an infectious disease epidemiologist at Johns Hopkins University. “There are creative ways to reduce the impact.”

Regular hand washing, which can reduce the spread of all types of pathogens, is always a good idea. “The message at the beginning of the pandemic to wash your hands and wash your hands for at least 20 seconds – that is absolutely valid and still very important,” said Dr. Hartmann.

And if the office needs to be cleaned yourself, a mild detergent is usually enough, she adds, “Soap and water are great.”

Masks also remain effective. “If you are someone who has been vaccinated and is still afraid of going back to work, it is best to keep wearing a mask for the first few weeks until you feel better,” said Dr. Everyone.

Scientists recommended that unvaccinated workers continue to wear masks in the office. But for those eligible, the most effective risk reduction strategy is obvious, said Dr. Allen: “Number one is to get vaccinated.”