For more than 25 years, Tom Smith has run 3Flow, a company whose sole mission is to make sure people don’t get sick from airborne hazards in their workplaces.

He suddenly has the attention of a lot of employers who never really gave thought to it before the pandemic.

Typically, Smith’s team focuses on how the air moves through places like labs or factories, but since the pandemic started, his business has been getting calls about open layout offices, conference rooms and auditoriums.

“A lot of people have found out that their systems are dysfunctional,” Smith said.

Office spaces are often a lot harder to work with than labs, Smith said, because they weren’t designed with floating pathogens in mind, and the systems have not been well maintained. He says there’s a simple reason for that: it wasn’t required.

“There is no certification or requirement to provide a risk assessment, to evaluate the effectiveness of the airflow systems or to manage and maintain them,” Smith said. “There’s simply nothing.”

Voluntary guidelines and standards have tried to fill the gap in governmental requirements. Yet even those, experts say, set a bare minimum rather than a standard for healthy indoor air.

However, the lack of individual knowledge and official oversight may be changing. Experts say one silver lining to the pandemic could be much-needed improvements to offices’ poor air quality, and hope that the pandemic could finally lead to formal guidelines.

Many employers are beginning to call their employees back into the office, while nervously eyeing the highly contagious delta variant. The desire to return to offices has put a spotlight on how workplaces can maintain high indoor air quality and, hopefully, prevent COVID-19 from spreading in the air from one desk to the next.

Over the years, there have been major advances improving health and safety protections in various aspects of our daily lives — our water, sanitation and food.

“But we haven’t done the same for indoor air — and it’s overdue,” said Joseph Allen of Harvard’s School of Public Health and author of Healthy Buildings: How Indoor Spaces Drive Performance and Productivity.

Allen and others have long been warning of the dangers of indoor air quality. Indoor pollutants from things like furniture, flooring, cleaning supplies and mold can create indoor air pollution as much as 20 times worse than outdoor air, he says.

When there’s cleaner indoor air, lives improve: kids score better on tests, productivity goes up and sick days go down. Now that COVID has highlighted that indoor air quality can be a matter of life and death, people are beginning to pay attention.

“I think this is the moment because everyone’s awareness is so high,” said Allen.

“Couple of years ago, I was just trying to get people to listen to me. Now that is not a problem,” said Theresa Pistochini, an expert on indoor air quality and co-director of engineering at the UC Davis Energy Efficiency Institute and Western Cooling Efficiency Center.

For decades, buildings have been able to earn LEED certifications if they are environmentally friendly. Now, the group that grants those certifications — the U.S. Green Building Council — is offering recommendations in light of the pandemic to help buildings manage and design their indoor air quality.

Both the Environmental Protection Agency and the professional organization that sets minimum air quality standards, ASHRAE or American Society of Heating, Refrigerating and Air-Conditioning Engineers, have put out recommendations for how to ensure high-quality air when in an office building.

Experts are hopeful that the heightened awareness and initial steps will lead to more fundamental change.

In the meantime, however, they say that individuals can do several things to protect themselves. First and foremost is getting vaccinated and wearing masks in the workplace. Opening the windows also increases ventilation, experts say.

But there are also several ways to check on a workplace’s indoor air quality. The number-one prioritiy is making sure it’s using really good air filters.

“You should ask pointed questions about ventilation and filtration,” said Allen. “And if they come back and say, ‘We're meeting the standard,’ you should know that the standard is a minimum standard not designed for health — and certainly not designed for protection during a pandemic.”

There’s a scale for filters called MERV, or Minimum Efficiency Reporting Value. The higher number, the better it is at removing smaller contaminants. The magic number for COVID is 13, or higher. The typical building uses MERV 8 filters, and the typical home uses MERV 4.

“If I were working in a building, I’d want to see the receipt. I’d want them to take me to the mechanical room and show me the box of MERV 13 filters. I want to actually see it personally,” said Pistochini.

But, she said, if the building is old or the system can’t support MERV 13 filters, there’s another option. Portable air cleaners with a HEPA filters — from local hardware store or online — are “a good temporary Band-Aid.”

“That is a simple, tried and true and effective measure for cleaning air of particles,” said Allen.

Finally, both Pistochini and Allen said, every employee should know that you can get a sense of the air quality for yourself.

“There’s a terrific way to know if you’re getting enough outdoor air, and that is through the use of carbon dioxide monitoring, or CO2 monitors,” Allen said.

People exhale CO2. So, portable monitors offer a rough gauge of how much we’re inhaling the breath that others are exhaling — it’s a proxy for just how much ventilation there is in a space. Since COVID viruses ride along in the air we breathe out, having a sense of how much fresh air we are breathing is helpful. If the number ticks much past 1,000, experts say, it’s probably time to open some windows or ask your employer for that HEPA filter on your desk.