Employers and employees around the world are anxious to get back to work as soon as possible. A picture of how that will unfold is starting to emerge – and it’s far from straightforward.

Businesses have long relied on a five-tier inverted pyramid called the “hierarchy of controls” to reduce workplace risks to employees, ranging from chemical exposure to physical injury. This framework will also be the basis for companies’ plans to get back to work, occupational safety experts say.

Companies in China have already begun following the hierarchy to restart production. But the process has been expensive and slow, as it is likely to be in the United States. That’s because many of the standard tools for workplace safety are ineffective against a risk like the coronavirus.

Distributing face masks and nagging employees to wash their hands count among the more uncertain methods for ensuring employee safety, experts say. But these are largely the methods that Chinese companies have been relying on as they have restarted production – and American businesses may not have many better options.

Governments and companies face a difficult choice in coming weeks: They can either reopen business with layers of stifling and expensive hygiene controls, or return to work with fewer controls and accept the risk of second-wave infections. Either way, there is no silver bullet against further community spread, and the global economy cannot sustain a lockdown until a vaccine is developed – which could take at least another year.

Susan Arnold, an associate professor at the University of Minnesota’s School of Public Health, said the most effective way – the top rung of the hierarchy of controls – to keep workers safe from a health risk is to eliminate it from the workplace. This is easy if the risk is a toxic chemical or dangerous machine, but not currently possible for the virus, she said.


“When we have a vaccine that’s widely available and accessible, then we will be in the position to eliminate that hazard from the workplace,” she said. “The only other way to do that right now is to shut workplaces down.”

As Chinese businesses return to work, Beijing has sought to reduce the transmission risk by requiring employers to check employees’ health and temperature daily, with quick quarantines for anyone showing symptoms. But some COVID-19 patients are asymptomatic, and test kits can produce false negatives, making these checks far from foolproof.

The next most effective method on the hierarchy of controls is to find a safer substitution. Again, this works when swapping out a toxic chemical for a safer one in a manufacturing process, but is not applicable to COVID-19, said Kirsten Koehler, an associate professor in environmental health and engineering at the Johns Hopkins Bloomberg School of Public Health. “In this case, we can’t swap one virus for another.”

That leaves the three rungs that workplace safety experts have long considered the least effective and most costly: engineering controls, administrative controls and personal protective equipment, or PPE.

Engineering controls, or redesigning workspaces to physically prevent virus transmission, are the next line of defense. In the United States, the Occupational Safety and Health Administration is recommending that retailers consider installing “sneeze guards,” or walls of plastic or glass, to protect cashiers. Companies should also consider adjusting production lines to provide more space between workers.

At many Chinese factory canteens, cardboard dividers have been set up on lunchroom tables to separate diners. Some factories also have placed mats soaked in disinfectant at entrances.


One engineering control is to improve ventilation, either through air filtration or introducing outside air, said Koehler.

Many of the measures that are easiest for businesses to adopt are administrative controls, which are safety protocols for workers to follow – for instance, frequent handwashing.

Also included are work schedules that minimize employee crowding. Some Chinese Internet companies have returned to work in recent weeks on “AB shifts,” with two teams coming into the office on alternate days. ByteDance – the parent company of viral video clip platform TikTok – recently reopened its office in Wuhan on such a schedule, as has Chinese Internet search giant Baidu.

Koehler said factories may face limits in how much they can space out assembly lines, but they could at least consider leaving some time between shifts to minimize crowding.

The small, pointy base of the hierarchy of controls is personal protective equipment, which occupational safety experts consider the least-effective method and the safeguard of last resort. The emergence of the term “PPE” as a household phrase in recent weeks reflects how the other four rungs have proved ineffective at stemming the spread of the virus.

There is growing international consensus that workers outside the health-care industry should also wear face coverings for protection, though also concern that scarce mask supplies might be diverted from hospitals if the general public scrambles for them. The Centers for Disease Control and Prevention has recommended the American public wear cloth face coverings, not medical-grade masks.

In China, some manufacturers like Foxconn have begun producing their own masks to ensure a steady supply for their assembly-line workers.

Arnold said employers should consider what they can do at each of these five levels, as they prepare to reopen.

As for employees preparing to go back to work, she said: “Just be mentally thinking that any of my co-workers could still be potentially a source of exposure. Anything I touch could potentially be a source of exposure.”

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