Children's Burned Hands Inspire Design of Safety Device for Clothing Irons
December 12, 2008
At team of surgeons and chemical engineers from the University of Rochester has designed a device to end the steady stream of five-and-under children who arrive at the hospital with hands burned by clothing irons. Their just-published research results on the new “iron shoe” argue that it could considerably improve home safety.
About once a month, and 212 times since 2003, a child comes into the University of Rochester Medical Center's Strong Regional Burn Program with a contact burn from a clothing iron. They tend to come from lower income families where the ironing is more likely to be done on the bed or floor than on an ironing board. The typical burn is second degree on children who have touched the iron with their fingers, and third degree if the child has yanked on the cord, causing the iron to land and remain on the back of the hand. According to a 2006 study published in the American Journal of Behavioral Health, about 78,000 U.S. infants and toddlers are treated in ambulatory care settings each year for contact burns from a hot object or substance, with clothing irons among the leading causes.
In the fall of 2005, Christopher Lentz, M.D., FACS, FCCM, director of the Burn Program decided to try to design a device that could prevent the burns, and sought a polymer expert who could help him chose the right material. He found Mitchell Anthamatten, Ph.D., assistant professor of Chemical Engineering at the University of Rochester, and together they wrote a successful grant proposal to the International Assoc. of Firefighters for funds to support research into possible solutions. With the grant secured, they formed a task force consisting of the Burn Center, Injury Free Coalition for Kids of Rochester, Finger Lakes Regional Burn Association, Rochester Fire Department and the Department of Chemical Engineering at the University of Rochester. The group’s goals were to identify the groups most at risk, develop a prevention campaign, distribute safety information and create a device to protect toddlers from contact burns.
“Surgery to graft new skin over the area is often necessary with these burns, which comes with a five-day stay in the hospital and month of recovery time,” Lentz said. “Some children suffer a permanent loss in their sense of touch on the injured fingertips, and scar tissue on back of hands may hinder movement. We grew tired of watching these kids come in and decided to try to do something about it.”
The task force first fielded a survey of patients and families in the burn center which found that most people believe a clothing iron, when turned off, takes 20 minutes to cool to the point where it will not cause a burn (120 degrees F), when it actually takes 90 minutes. In response, they developed a safety brochure distributed at the Medical Center (e.g. Ob-Gyn floors) on iron safety.
They also launched a contest for chemical engineering students, challenging them to come up with a low-cost, effective way to prevent content burns. If inexpensive enough, they thought, such a device might even be sold as a package with the iron.
The team settled on a “safety shoe,” a device in which users could leave the iron in when hot, but no longer in use. The surface on which the iron rests within the shoe, they decided, should have raised bumps to create insulating air gaps that further isolate the iron’s hot surface, and the shoe’s sides should come high enough to protect children from the iron’s edges.
They decided to make the shoe out of an insulating polymer made by Dow Chemical’s called SILASTIC® Silicone Rubber, which been shown to retain its shape and performance through 2,000 hours of 500 °F heat. It was also easy to shape. The team next designed and fabricated a low-cost (estimated at $5 to manufacture) safety shoe prototype, and tested it.
Their results, just published online in the December edition of the Journal of Burn Care Research, showed that the shoe was easy to use, safely shielded the edges of the iron and did not melt or deform. They found that the temperature on the outside of the shoe did not exceed the burn safety threshold of 120°F (49°C) when a hot iron was unplugged and placed in it.
Even when the iron’s heating plate was left on while it rested in the shoe, and reached a temperature of 320°F (160°C), the external temperature of the safety shoe reached only 212°F (100°C). That still might cause a lesser burn, but was well below the temperature at which paper, for instance, catches fire (451°F). The addition of a Velcro strap over the top would likely prevent burns caused if a child pulled it off of a raised surface or tried to take it out of the safety shoe, researchers said.
Along with Lentz and Anthamatten, Ryan Beers, Dixie Reid, PA-C, and Steven Kahn, M.D., led the effort.
“The students showed great creativity in addressing this problem, suggesting everything from a glass fiber pillow for the iron to a Kevlar shield,” Anthamatten said. “The elastic polymer shoe proved to be the best idea, and we believe it could really make a difference if a company decides to invest in it.”