Rather than air, they are chemical blowing agents, hydrofluorolefins (HFO), which are injected into the raw material. Thus, the PSX contains tiny gas bubbles, which slow the movement of heat and give their insulating properties to the foams. This blowing agent, used since 2017, has a much less intense environmental impact than its predecessor: it is non-toxic, does not damage the ozone layer and is not considered as a volatile organic compound (VOC) by Environmental Protection Agency (EPA) ( see our article on PSX bulking agents ).

Flame retardant treatment: progress!

Cellulose insulation gets its flame retardant qualities from boron salt, a natural and healthy product. Rigid polystyrene insulation, until recently, contained hexabromocyclododecane, HBCD , a dangerous bromine-based flame retardant. Dangerous because this toxic synthetic molecule hardly degrades and accumulates in living tissue. It is an endocrine disruptor toxic to aquatic organisms, animals and humans. Due to its use in large quantities in the fabric and electronics industry for example, HBCD is found everywhere today: in water and soil, at sea and even in the polar regions. On the polystyrene side, there was no evidence that HBCD trapped in the material also released into the environment. You can go for the Polystyrene cut sheets there.

In May 2013, during the Stockholm Convention on Persistent Organic Pollutants (POP), which brought together more than 150 countries, the HBCD joined the list of the 20 most dangerous pollutants. The polystyrene insulation industry started replacing HBCD at this time, and in 2017 it was completely abandoned for a new flame retardant, Polymeric Flame Retardant (PolyFR or PFR). This non-bioaccumulative flame retardant was developed by the American multinational Dow Chemical, which subsequently sold the patent to various chemical companies, which in turn were able to sell it to insulation companies.

It will still be necessary to wait for the long-term results of its impacts because the new retarder still contains bromine, a persistent element in the environment. The risks are however lower since the PFR is polymerized in polystyrene, a process which completely encloses the flame retardant in the beads. This development is therefore good news.

It is the same material, but the extruded polystyrene is of better quality thanks to a special treatment, and has grooves to facilitate installation.

Extruded polystyrene therefore has better insulation performance .

Main Characteristics Of Polystyrene

Polystyrene is a material which demonstrates good thermal insulation qualities. However, it is not very ecological.

Polystyrene is produced from petroleum, an expensive and polluting resource. It is therefore not an ecological insulator , especially since its manufacturing process is complicated and consumes a lot of energy.

However, it has a very low thermal conductivity , which makes it an effective insulator .

Furthermore, it is absolutely not fire resistant, and must therefore be combined with another material. It is also not resistant to rodents.

Polystyrene is impermeable to water vapor and does not dissipate moisture .

However, its sound insulation is almost zero.

About the Company: Foam Technologies are one of Australia’s leading polystyrene suppliers, servicing the building and construction sector.