Susan S. Xu, Ph.D. 

Firefighters depend on gloves to shield against extreme heat, yet they typically provide less than 20 seconds of protection before allowing second-degree burns, leading to injury and disrupting critical rescue work.

In 2023, Susan Xu, an engineer at the National Institute for Occupational Safety and Health, deployed 3D modeling to develop a new glove that uses phase-change materials—substances that regulate temperature by absorbing and releasing thermal energy—to provide up to two times as much protection to more than 1 million U.S. firefighters, enabling them to endure more prolonged heat exposure.

She also conducted research to establish safer weight limits for self-contained breathing apparatuses, reducing the prevalence of musculoskeletal injuries in firefighters, and developed new guidelines and technologies that have critically enhanced personal protective equipment for health care workers.

“She’s advancing science that helps protect firefighters so they can withstand higher temperatures and rescue more people,” said Capt. Harold Boyles, deputy branch chief at NIOSH.

“Her contributions have profoundly impacted safety standards and public health, and she continues to lead pioneering research on personal protective equipment. Her 3D modeling and simulation methods reduce the need for extensive human testing in PPE design, saving time and expenses,” added Hom Sharma, a general engineer at NIOSH.

Boyles credited Xu with identifying gaps in NIOSH research and doing innovative “high-risk, high reward” work that makes a real-world difference for workers who use PPE.

Recognizing musculoskeletal injuries as firefighters’ primary cause of injury, Xu led a biomechanical modeling and simulation project in 2022 to establish lower weight limits for the self-contained breathing apparatuses that firefighters use to inhale clean air when entering smoke-filled conditions. The new standards are currently under consideration by the National Fire Protection Association, which sets safety codes for the fire industry.

During the COVID-19 pandemic, she also developed a sensor that can be inserted into masks to alert health care workers to leakage in real time as well as a requirement that powered air-purifying respirators, typically full-hooded masks or body suits that protect against contaminated air, allow health care workers to communicate with each other without removing their PPE. These innovations are helping 18 million front-line employees who rely on NIOSH-certified equipment to prevent infection.

Xu, who has been in government for nearly a decade, said she likes seeing her research being used to make a difference and regularly seeks opportunities to make further advancements in PPE design. NIOSH is currently planning to coordinate with manufacturers about mass producing her new firefighter glove, although significant workforce cuts may impact the agency’s overall work.

“We hear directly from the front-line workers and see the injury rates. Then, I look at the data and think about how to improve outcomes for workers,” Xu said. “It feels really good to help people.”