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How to test for indoor air hazards

By Stefan Dubowski
| www.cos-mag.com

Poor indoor air quality poses serious health risks to workers – learn how to watch for telltale signs of bad air

When a staff member or student at the University of Ottawa complains about the “smell” of carbon monoxide, Michael Histed takes the issue seriously — even though he knows the complaint is off base.

Histed, the university’s director of risk management, knows full well no one can smell carbon monoxide. Although the gas is toxic at certain concentration levels, it is odourless.

Nonetheless, the person reporting the issue may actually be smelling exhaust fumes from the parking garage seeping into the ventilation system. Since car exhaust produces carbon monoxide, the matter is worth an investigation.

“Indoor air quality is important because our staff are here seven, eight hours a day — and our students, sometimes longer,” Histed says. “It’s a matter of the quality of your work environment.”

Thanks to numerous reports, studies and news items about indoor air quality (IAQ), people know it affects their health in all sorts of ways. 

So what can health and safety managers do to ensure good IAQ in their work environments?

According to experts, managers need a solid understanding of common indoor pollutants, and a system for identifying and dealing with problems.

Signs and sources

Poor IAQ can cause a range of problems, including sinus congestion, difficulty breathing, nausea and headache. Mold, chemicals or carbon monoxide may be the source of the issue.

The workplace can be a haven for poor air quality — depending on what type of environment, equipment and materials are present at any given point.

If someone complains about carbon monoxide or exhaust fumes, it’s time to investigate the ventilation system. If the intake is located near a roadway or loading dock, it may be pulling exhaust from vehicles into the office.

Sometimes people worry renovation dust contains asbestos, especially with respect to renovations in older buildings. The carcinogenic material was commonly used as a fire retardant in the past.

People also worry about volatile organic compounds (VOCs) — potential carcinogens from new wood products, paint and carpeting — although carpet manufacturers dispute the notion that carpeting is a major VOC emitter.

Previous studies have shown laser printers, photocopiers and fax machines emit ultrafine particles, which are linked to heart and lung problems.

If the workplace uses chemicals, employees may be concerned about toxic fumes.

People’s lifestyle compounds these problems: most people spend a lot of time indoors, so if IAQ is poor, its effect is more concentrated.

That buildings are practically sealed nowadays complicates matters further.

“Consider what we went through a couple of decades back in the ’70s and ’80s, after the oil crunch, when everybody’s primary concern was making their buildings airtight so they could spend less on heating and air conditioning,” notes Charles Geen, senior project manager at AirZone One, an indoor air quality testing company in Mississauga, Ont.

“The concentration of some of these chemicals inside is higher than it is outside, because the air exchange with the outdoors is quite low.”

Conducting investigations

Health and safety specialists need a system to identify air-quality problems. Fortunately, numerous resources are available to help develop comprehensive investigation plans.

Health Canada’s Indoor Air Quality in Office Buildings: A Technical Guide covers issues such as “sick building syndrome” (complaints from office workers about indoor air pollution), ventilation guidelines and assessing air quality.


Hamilton, Ont.-based Canadian Centre for Occupational Health and Safety (CCOHS) offers a sample inspection checklist of the tasks required for thorough IAQ investigations. This checklist, and other resources on IAQ investigations, can be found on the CCOHS website, www.ccohs.ca.

The University of Ottawa’s office of risk management uses a detailed process to deal with poor indoor air quality — beginning with identifying the source, assessing the ventilation system and implementing a remedy. The process includes reassessments if the prescribed remedy doesn’t address the issue.

The university publishes its process on a public website so faculty, staff and students can see exactly what is in store if they have an indoor air quality complaint.

“Being open about your process is important,” Histed says.

Transparency helps the school’s population understand complaints are taken seriously, and that helps validate the results.

Path to improved IAQ

Creating a reliable process for air quality investigation is one thing — but it’s not the only thing. Managers also need to get a handle on the materials and actions their organization can use to improve IAQ. For instance, in renovations and new construction projects, use low-VOC paint and carpeting.

“Let the building air out for a couple of weeks before you put your employees in,” says Barbara MacKinnon, president and CEO of the New Brunswick Lung Association in Fredericton. That’s because VOCs dissipate over time, she says.

Think about the location of photocopiers, printers and fax machines. Are they situated near an employee work area? If so, consider moving the equipment to a less populated space. The farther away these devices are, the better, since ultrafine particles are concentrated close to their sources, MacKinnon says.

Consider conducting air sampling to identify IAQ problems. While some organizations have their own sampling equipment for temperature, humidity, carbon monoxide and carbon dioxide, third-party specialists typically use finely tuned sampling equipment to identify more obscure sources.

Timing of the sampling is crucial. To fully understand the problem, it is recommended sample collection be done when concentrations of potential substances are likely to be high.

Also, consider the times of day at which the user population is affected. For instance, although delivery trucks arriving overnight emit exhaust fumes at their highest concentrations at 3 a.m., employees don’t arrive until 9 a.m. In this case, there’s no reason to collect samples in the wee hours of the morning.

“You want it to be as representative as possible for the population you’re trying to protect,” says Geen.

An air analysis laboratory will scrutinize the samples, usually providing results within 10 days (although many labs can put a rush on the analysis and have it ready in one day for an extra fee).

A thorough investigation helps pinpoint the cause of poor IAQ — and having a step-by-step process helps ensure investigations are comprehensive. That’s important if the ultimate goal is a healthy work environment.

Experts also point out that it’s essential to acknowledge the high degree to which the general public is attuned to IAQ issues. Employees will need to see that the processes are prescriptive if employers want them to accept the results of investigations.

In that vein, Histed says you need to take things slow.

“Don’t jump to conclusions. It’s easy to say, ‘It’s car exhaust coming into the building.’ Well, maybe. You have to consider the person’s symptoms and the actual complaint.”

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Stefan Dubowski is a freelance writer based in Ottawa. You may contact him by email at [a target="_blank" href="mailto:dubowski@stiffsentences.com"]dubowski@stiffsentences.com

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