With the changing environment, bushfires have noticeably increased their ferocity, leaving many families devastated. Take control and protect your home by choosing UPVC double glazed windows and doors, which are non-combustible and self-extinguishing. UPVC double glazed windows and doors are an excellent alternative to wood for those living in bushfire-prone areas. In fact, one of the few homes to have survived the Marysville bushfire in Victoria had UPVC windows, and PVC was extensively used in other parts of the home.

Our UPVC windows and doors are notoriously difficult to ignite with common ignition sources such as matches and lighters. Furthermore, tests on our products under varying heat intensities have demonstrated that UPVC will only burn while the fire source is applied, and when the source is removed, there is no residual flame. In general terms of ignitability, UPVC is relatively hard to ignite at 390 degrees compared to pinewood at 260 degrees. Once UPVC is ignited, the associated hazard can be measured by applying a Limiting Oxygen Index (LOI) test.

The LOI test measures the concentration of oxygen in an oxygen/nitrogen mixture necessary for sustained combustion. According to some independent testing (Hilado, CJ Flammability Handbook of Plastics, 1990), UPVC has an LOI of 45-50, compared to 21-22 for wood. For material with an LOI of 21 and above, it should not burn in air at room temperature, where air contains 21% oxygen. With a LOI result of 45-50, this indicates that UPVC will only burn in conditions of very high heat.

When UPVC burns, it will give rise to smoke, just like most natural and synthetic materials. However, contrary to popular urban myths, independent scientific studies have concluded that UPVC fire gases are not significantly more toxic than those from other building materials (Horrocks AR, Price D "Fire Retardant Materials" 2001). In terms of heat release, PVC has a higher heat of combustion than wood or paper, but the rate of release is lower than most organic materials, meaning that burning UPVC is unlikely to develop enough heat to ignite nearby objects and spread the flame. The UPVC formulation used for the window profile inhibits the spread of flame through the development of a carbonaceous char when burning instead of dripping.

Smoke is another important consideration because it can be lethal and obstruct a safe exit route. Smoke results from the incomplete combustion of a burning material. Under non-flaming conditions, UPVC produces the same smoke densities as wood. UPVC can produce a greater total quantity of smoke under flaming conditions, but the rate of smoke per unit of time is still lower than that of most organic materials because of PVC's low heat release during burning. This implies that using PVC in a home may allow fire victims additional time to escape without being hindered by smoke. In one experiment undertaken in the US National Bureau of Standards smoke chamber, comparing different materials, UPVC had a maximum specific optical density score of 400 under non-flaming conditions, while pine scored 551 and oak 581.

Today, PVC is used in many safety applications where fire retardancy is critical, such as cable ducting. Of course, no amount of safety features will replace common sense, so we urge our customers to be aware and alert to potential dangers. The UPVC we use has been formulated to combine excellent technical performance and high resistance to ignition and flame spread, allowing our customers to take advantage of science for a more comfortable and safer living environment. All our products are manufactured in Sydney, ensuring the highest quality and standards.