Michael Kelly Mort Kondracke Ch. The greater the percentage of polyester in a cotton-poly blend, the safer the garment. Many polyester fibers extinguish on their own, a fact that can go a long way toward limiting the potential for injury. We discovered this during flammability tests performed on some 2,400 fabric swatches cut from a large selection of men's, women's and children's clothing.
All fabrics burn at some point when exposed to a flame, some faster than others.
Smooth fabrics meet the government's highest safety level if, when a flame is applied to a swatch, it takes at least 3.5 seconds to burn a 5-inch path.