After last week's threats from North Korea that it was planning to create an "enveloping fire" around the US territory of Guam, Guam's Office of Civil Defense issued a set of just-in-case guidelines – which you can also find here - on how to stay safe after a nuclear attack. There are a lot of interesting tips and warnings in these guidelines, but one that sticks out is:
"Wash your hair with shampoo or soap and water. Do not use conditioner in your hair because it will bind radioactive material to your hair, keeping it from rinsing out easily." This is especially important if you haven't been able to immediately find inside shelter.
According to NPR:
If you shower carefully with soap and shampoo, Karam says [Andrew Karam, radiation expert], the radioactive dust should wash right out. But hair conditioner has particular compounds called cationic surfactants and polymers. If radioactive particles have drifted underneath damaged scales of hair protein, these compounds can pull those scales down to create a smooth strand of hair. "That can trap particles of contamination inside of the scale," Karam says.
These conditioner compounds are also oily and have a positive charge on one end that will make them stick to negatively charged sections of a strand of hair, says Perry Romanowski, a cosmetics chemist who has developed personal hygiene formulas and now hosts "The Beauty Brains" podcast on cosmetics chemistry.
"Unlike shampoo, conditioners are meant to stay behind on your hair," Romanowski says. If the conditioner comes into contact with radioactive material, these sticky, oily compounds can gum radioactive dust into your hair, he says.
For that matter, Romanowski says in the event of a nuclear blast, you might want to consider forgoing most personal care products that are sticky or oily. "Skin lotions or moisturizing lotions or color cosmetics that have oils — these go on your skin and can attract dust or radiation particles from the air. So that would be a concern," he says.
Fortunately, North Korea has stated that it no longer plans on firing missiles at Guam.
Image: Esther Max