Wool study proves suitability for military and fire fighters
AWI has funded a new scientific study into the fire resistance of various fabrics used as base-layer garments for military and first responder personnel such as firefighters. The study concluded that the wool and wool rich fabrics in the study performed the best, while the 100% synthetic fabrics (polypropylene and polyester fabrics) performed the worst due to their propensity to melt and damage the skin.
From the Battle of Waterloo to the Korean War, wool’s inherent ability to protect the wearer from hostile environments, including extreme cold and fire, made it the military’s fibre of choice for outer layer garments. Nowadays, the military and first-responders are looking to base-layer wool garments due to the health and safety benefits offered by this ‘last line of defence’.
“This growing market demand for wool base-layer garments relates to the already well-researched benefits of superfine Merino wool, including its softness next to the skin, moisture management, breathability – and fire resistance,” said AWI’s Program Manager for Fibre Advocacy and Eco Credentials, Angus Ireland.
The increased demand has in part been driven by the incidence of injuries to military personnel in the Middle East, where battle techniques such as improvised explosive devices (IEDs) were used. Considerably more severe skin injuries occurred when synthetic base-layers were worn, as they can melt onto the skin at high temperatures.
A review in 2017 by AgResearch of base-layer undergarments worn by the military, fire service and police first responders revealed that, worryingly, there are often no required specifications or test method standards relating to these important protective garments. This results in cotton or synthetic base-layers often being chosen by some military and emergency service personnel.
Some personnel choose cotton because it is the cheaper alternative and perceived as being a cooler option. However, there is the risk of large amounts of sweat/moisture building up in a cotton garment when worn in a layered system, which at high heat intensities increases radiant heat transfer and can lead to steam burns and increased levels of stress.
There’s also a trend for personnel to choose synthetic ‘moisture management’ (wicking) sportswear garments. The key concern with synthetic fibres (even flame-retardant ones) is that, when they are exposed to flame or extreme heat, they melt and drip which can result in molten polymer coming into contact with the wearer’s skin and burning it.
“In contrast, wool fibres are known to have a natural resistance to burning, even when exposed to an ignition source for long periods. This is due to wool having a high ignition temperature, high limiting oxygen index and its self-extinguishing behaviour,” Angus said.