Alice Stoll, a research physiologist and pioneer in aerospace medicine, led the development of fire-resistant fabrics in the 1960s. Her work made it possible to rate materials by their ability to protect from thermal burns and demonstrated that fabric constructed with fire-resistant fibers was superior to fabric treated with a flame retardant.
Born on Long Island, New York, in 1917, Stoll earned her bachelor’s degree in chemistry and physics from Hunter College in 1938. Enlisting in the U.S. Naval Reserve during World War II, Stoll was on active duty from 1943 through 1946 before serving in the Reserve for the next 20 years. In 1948, Stoll earned her master’s degree in physiology and biophysics from Cornell University Medical College.
Early in her career at the Naval Air Development Center in Warminster, Pennsylvania, Stoll compiled data from previous studies on the effects of centrifugal acceleration on chimpanzees and humans for applications in aviation and space flight. She used this data to develop a Stoll Curve describing human tolerance to centrifugal acceleration. This work helped aircraft designers determine when conditions required pilots to be protected against high G-force effects.
In the late 1950s and early 1960s, Stoll worked with chemist Maria Chianta to determine the level of heat energy required to cause second-degree burns, and then developed a different Stoll Curve — one that charts the heat levels and durations required to produce second-degree burn injuries and pain under various exposure conditions. Stoll and Chianta found that the degree of skin damage did not depend on the source of heat, whether radiant or convective, but rather on the elevation in skin temperature and the total exposure time.
Stoll’s research yielded foundational knowledge on thermal burns and their prevention. Previously, using fire-retardant treatments on fabrics was considered the best method of protection, but Stoll’s work showed that it was possible, and in fact preferable, to construct fabrics with fire-resistant fibers.
In the early 1960s, Stoll patented a device to test fabrics and measure their properties, including thermal diffusivity, conductivity and flame destruction temperature. The device also measured the fabrics’ ability to insulate against heat, helping to predict the physiological effects on skin beneath one or more layers of the fabric under severe heat conditions.
After testing more than 200 materials, Stoll identified a synthetic polymer called HT-1, later marketed by DuPont as Nomex®, as the best fiber for fire-resistant clothing. When this flame-resistant aramid fiber is exposed to extreme heat, it thickens and carbonizes, absorbing heat rather than transmitting it through the fabric to the wearer. Unlike nylon and other synthetic fibers, Nomex fibers do not melt or support combustion, which exacerbates injuries as hot fibers adhere to skin. Nomex proved to be so effective, it was used to create the first inherently fire-resistant protective clothing for U.S. Navy personnel. The other U.S. military branches also began issuing protective clothing made from Nomex, as did fire departments, and the fiber found use in a wide variety of civilian applications.
In 1966, Stoll retired from the U.S. Naval Reserve with the rank of commander in the Medical Service Corps. She served as the head of biophysics and bioastronautics division at the Naval Air Development Center’s Aerospace Medical Research Department until 1980. She held two U.S. patents and received many honors including the Society of Women Engineers Achievement Award in 1969 and the Presidential Award Citation for Innovation in 1972.