Sunscreen’s not flammable; aerosols are

A Massachusetts man was burned severely while using a backyard grill just after applying sunscreen spray. But dermatologists and burn experts called it a freak occurrence caused not by the sunscreen, but by the fact that the man was using an aerosol spray near an open flame.

Sunscreen is not usually flammable. But like hair sprays, deodorants, insecticides, paints and other products that can be sprayed out of a can or bottle, sunscreen can become flammable when used in aerosol form, said Dr. Darrell Rigel, a clinical professor of dermatology at New York University.

The man, Brett Sigworth, got severe burns on his chest and back and an ear. He reportedly had just sprayed himself with layers of aerosolized sunscreen before walking over to his grill.

Rigel said in more than three decades of practicing, he had never seen or heard of a similar occurrence.

“Most of the sunscreen sprays have some kind of alcohol in them,” he said, “and the alcohol vapors are probably what caused the fire.” Other chemicals that are used to make aerosols — things like volatile hydrocarbons, propane and dimethyl ether — are also flammable.

The bottle Sigworth used bears a warning label about flammability, similar to those found on hair spray and other aerosol products.

“He was most likely surrounded by alcohol vapors,” Rigel said. “If you do that with hair spray, the same thing would happen. I suspect even if you sprayed yourself and then lit up a cigarette right away, the match might be a trigger, or the red-hot cigarette might do it, too.”

The company that makes the spray, Banana Boat, said it was unaware of any similar episodes but was taking the matter seriously.

In recent years, the popularity of spray-on sunscreens has risen sharply. But should sunbathers worry this summer that a few spritzes of sunscreen might make them a walking fire hazard?

“People shouldn’t be worried that if they spray sunscreen on they’re going to explode,” Rigel said. Instead, take precautions, most importantly waiting two minutes after spraying sunscreen before getting anywhere near a grill or open flame, he said, which gives the alcohol enough time to evaporate.

Dr. Karthik Krishnamurthy, a dermatologist at the Montefiore Einstein Center for Cancer Care in New York, said he and his colleagues had never heard of someone catching fire after applying sunscreen. “The only real risk is with aerosolized spray cans, and it’s only when the spray is being discharged, just like with hair spray. I would encourage people to take it with a grain of salt.”