It’s expensive to keep cash circulating. Countries print 150 billion new notes each year, at a cost of about $10 billion. Cash attracts grime and dirt, gets stuffed into underwear drawers, is daubed with pens, and exposed to harsh UV light. In other words, money goes through a lot, with the result that 150,000 tons of it has to be destroyed annually.
As a new paper explains, one of the main problems with keeping money in good condition is sebum, the substance the body produces to protect the skin. Waxy and oily, sebum builds up on the surface of the paper and then reacts with the air, eventually turning bills a nasty shade of yellow. From there, it’s a short distance to the shredder.
The paper, published in an American Chemical Society journal, discusses a new process that might keep more notes circulating longer, and therefore cut the cost of printing and distributing new bills. It involves subjecting notes to supercritical CO2–carbon dioxide in a liquid state at a high pressure. In tests, the process led to “significantly fewer notes being classified as unfit due to soiling,” according to the study.
However, there is a simpler way of reducing cash’s cost, and that’s doing without it altogether and moving towards digital forms of exchange. Soiling isn’t the only problem. There’s also the price of securing cash and paying for bank robberies. Then there’s the role of cash in enabling crime and tax evasion, and keeping poor people out of the formal economy. (David Wolman’s book The End Of Money explores these and other problems.) Doing away with cash completely could save countries as much as 1% of GDP, one study showed. For the U.S., that would mean about $150 billion a year.
So, yes, let’s launder banknotes to keep them fresher. But then let’s think about going cashless. It could save even more dough.