Don’t try this at home, but scientists have come up with a way to
wash those worn and grimy dollar bills you might have in your pocket.
Using something called supercritical carbon dioxide could help
central banks extend the life of their paper notes.
According to a Jan. 8, 2014, post on Popular Science
magazine’s website, “scientists successfully removed the
human gunk and motor oil from dollar bills by using supercritical
carbon dioxide, a fluid commonly used in other cleaning processes that
acts like both a gas and a liquid. The bills’ security features such
as holograms and phosphorescent inks stayed intact, safely and
effectively preserving the banknotes.”
The article notes that “this cleaning method could prevent bills
from becoming the ratty, old ones that vending machines hate and that
eventually need to be disposed of.”
And here’s the part of the story that possibly comes under the TMI
(too much information) heading.
“The primary source of a banknote’s aging and eventual yellowing is
human sebum, the oily waxy substance the body produces. Over time it
builds up on the surface of dollar bills where it reacts with oxygen
in the air and turns an aged yellow,” according to the article.
Read more of Coin World's recent paper money coverage: