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Spray Lights Up The Chemical That Causes Poison Ivy Rash

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Spray Lights Up The Chemical That Causes Poison Ivy Rash

Your Health

Spray Lights Up The Chemical That Causes Poison Ivy Rash

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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Here in California, we have news of breakthroughs on another awful skin condition, this one caused by poison ivy. One scientist developed a spray that can reveal the presence of the oily residue in poison ivy. For people who are highly allergic, the spray would let them know when they are exposed, so they could take aggressive steps to wash the oily residue away.

NPR's Joe Palca was itching to do this story.

JOE PALCA, BYLINE: I wanted to do this story because I am one of those highly allergic people.

REBECCA BRASLAU: Me too. This is how I got started on all this.

PALCA: Rebecca Braslau is an organic chemist at the University of California, Santa Cruz. Braslau has that horribly itchy poison ivy rash more times than she'd care to remember. She knows how to avoid the plant herself, but she can still get still get the rash. How?

BRASLAU: My husband's a geologist. He tramps around in the Santa Cruz mountains.

PALCA: And her husband is one of those lucky people who isn't allergic to the oily compound found on poison ivy leaves.

BRASLAU: When we first got together he wasn't very careful about it and so he would get it on his arm, and he wouldn't even know it.

PALCA: And then he'd put his arm around is wife and the oil on his skin would rub off on her, and she'd wind up breaking out in a rash. Her husband tried to be more careful, but Braslau got to thinking hey, I'm a chemist.

BRASLAU: There's got to be some way to deal with this, and I just had this Eureka moment because I thought about it for a couple years.

PALCA: The Eureka moment involved a class of chemicals known as nitroxides. Braslau studies nitroxides and she developed a nitroxide based solution that would only react with the oil in poison ivy. Then she added a fluorescent dye that switched on when the reaction occurred and bingo, she had a poison ivy detection system. She describes her work in the Journal of Organic Chemistry.

Braslau says it will take a lot of safety testing before she'd be confident enough to use her spray of someone's skin.

BRASLAU: Right now we're talking about maybe spraying it on your hiking boots, or your firefighting equipment, or your backpacking equipment or your chain saw, or inert objects where we wouldn't have to worry about applications onto human skin. Ultimately, I would love to be able to spray it on my arm, or my husband or my dog, and find out where this stuff is.

PALCA: OK, so her spray tells you the oil got on your hiking boots, but then what do you do.

BRASLAU: TecNu is a water-free cleanser. Mark Christensen is a chemist at Oregon State University who works with TecNu's manufacturer, Tec Laboratories of Albany, Oregon. I asked Christensen why TecNu was so good at removing poison ivy oil from someone's skin and he said it was because it contains a benzene ring which has ortho hydroxyls.

MARK CHRISTENSEN: And then para to that, off of that benzene ring it has a long alkyl unsaturated chain, 15 to 18 carbons.

PALCA: A little more technical than I was expecting, but the idea seems to be the chemicals in TecNu can mix with poison ivy oil so you can wash them off your skin.

There are other products if you can't find TecNu. Braslau says the hand cleaner called Goop that auto mechanics use seems to work - as do some dishwashing liquids. Or you can just say no, stay indoors and keep away from any spouse, friend or pet who likes to walk in the woods.

Now there's one other interesting thing I learned while working on this story. Turns out there a tree in Asia that produces great quantities of the poison ivy oil and artists treasure it. Why? Because it the oil makes an outstanding lacquer.

Antoine Wilmering is an expert in Urushi lacquerware, as it is known, at the Getty Foundation in Los Angeles. He says you apply multiple layers of the lacquer with a brush, cure and polish each layer...

ANTOINE WILMERING: And then you get these really beautiful shining surfaces.

PALCA: The good news is the curing process not only hardens the lacquer, it also causes it to undergo chemical changes so it no longer can make you itch.

Joe Palca, NPR News, Washington.


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