sydney skyline in smoke
Unfortunately, not even the top-of-the-line airconditioning filters in premium office buildings stop everything, such as gaseous carcinogenic contaminants such as formaldehyde.

It was a busy summer for Adam Garnys, principal consultant at CETEC, a technical risk management consultancy with expertise in indoor air quality.

The team was run off its feet testing buildings during the summer’s devastating bushfires to see how well they filtered out hazardous smoke particles.

As you might expect, the premium end of the market performed well. The data collected by the consultancy over the prolonged bushfire season showed that Premium Grade Buildings (as defined by the Property Council of Australia’s “Guide to Office Building Quality”) can reduce the outdoor bushfire smoke contaminants by up to 90 per cent.

This is good news for workers in A Grade buildings, which are generally Green Star rated for Design & As Built and therefore have decent indoor environment standards.

But for workers in lower grade buildings, the data suggests the workplace is not necessarily safe from smoke dust.

This is complicated further by the fact that employee homes might not be any safer.

Garnys says this raises questions about employer responsibility for health and safety, and what advice organisations should give about staying home or coming to work under extreme bushfire smoke conditions.

He says that companies have three choices: tell workers to come to the office, stay at home, or take the day off.

It’s a complex business decision because companies are still liable for workers who stay home, that is, your home is still considered a place of work if you get an asthma attack.

The only safe option from a liability perspective is to take the day off. But this means operations grind to a halt.

Garnys says that by engaging his company, his clients were at least equipped to make an informed decision, with many in the position to keep people coming into the office thanks to the quality of their buildings.

“It’s a strong case for high performing buildings.”

So what are premium buildings doing right?

The problem with standard airconditioning units is that the nasty smoke particulates (PM0.7-1.5 microns) and vapours are so small they can easily pass through a typical airconditioning filter.

The microscopic size of these particulates allows them to penetrate deep into the pulmonary regions of the lungs where air exchange occurs, which impacts everyone, especially people with impaired respiratory systems, such as asthma.

“In addition, bushfire smoke’s mix of potentially carcinogenic and hazardous chemicals can have irritating effects to the eyes and throat and this can increase the risk for susceptible individuals which should be taken into account for the business continuity plan.”

Unfortunately, not even the top-of-the-line airconditioning filters in premium office buildings stop everything, such as gaseous carcinogenic contaminants such as formaldehyde.

The testing over the height of the bushfire period (December and January) saw elevated formaldehyde in buildings with “no other reason why”.

While it’s not conclusive that the bushfires were to blame, Garnys says the findings were inconsistent with other times those same facilities had been measured.

That’s why the best protection from all bushfire smoke contaminants is to stop it wafting in in the first place.

He says the buildings with the best results not only had correctly installed filters, ideally of F9 efficiency, but also employed sensible building strategies such as no night air purges when the outside air quality was poor, and above-average HVAC maintenance.

Other strategies include running the HVAC intermittently on “recirculation” so that internal air is also filtered and by turning off the economy cycle (which is using 100 per cent outdoor air to supply air to the space).

These are the sorts of strategies facilities managers and building owners can do to improve air quality in buildings of all standards, he says.

Leave a comment

Your email address will not be published.