It might be the strangest advice imaginable for survivors of a nuclear attack: Don't use hair conditioner. But it turns out to be sound advice as well, reports Live Science. The matter came up when Guam, under threat of an attack by North Korea, recently issued safety guidelines to the public. And there among the usual seek-shelter nuggets was the warning that people should use soap and water to rid themselves of toxic dust but avoid the conditioner. It's all because of how the stuff works, and the upshot it that it could actually cause radioactive particles to bind to your hair.
Hair is shaped almost like scales, which can open up and come apart throughout the day. Conditioner uses compounds like silicone and cationic polymers to pull these scales back down and smooth it, one cosmetic chemist tells Racked. Conditioner is also oily, and any oily products like lotions or cosmetics are likely to encourage fallout to stick around. So there you have it: Wash with soap and shampoo, but let your hair frizz out. NPR also took a look at those safety guidelines and highlights one that would come in handy should doomsday arrive: If you see a flash, get inside anywhere as fast as you can to reduce exposure to fallout, and remove your outer layer of clothing. (Dandruff shampoo could be harming our water.)