The Receipt Problem

Most receipts are printed with heat, not ink

Run a fingernail across a fresh receipt and it leaves a dark line. That is because most receipts are thermal paper. There is no ink cartridge in the register. The paper itself is coated with a developer chemical that darkens when the print head heats it.

For years the most common developer was bisphenol A, better known as BPA, the same compound people learned to avoid in water bottles and can linings. On receipts it is not sealed inside anything. It sits loose on the surface, which is why it transfers so easily to whatever touches it.

One research team measured roughly 20 milligrams of BPA per gram of paper on the receipts they tested. Compared with the trace amounts that migrate out of a can, that is a lot of BPA sitting on the outside of something we hold with our bare hands.

Two hours of handling receipts, and three times the BPA

In 2014, researchers at Harvard and the CDC asked 24 volunteers to do something mundane: print and handle receipts for two hours, the way a cashier might. They measured the BPA in their urine before and after.

Without gloves, average urinary BPA went from 1.8 to 5.8 micrograms per liter. In a smaller group they followed over a full day, levels kept climbing for hours and peaked around eight hours after handling. When the same people wore nitrile gloves, there was no meaningful rise at all.

The authors were careful to note that the bump was smaller than what they had seen after people ate canned soup. That is a fair point, and also not very comforting. Receipts are one more small, daily source, and it is one of the easiest to cut.

Hand sanitizer, then a receipt, then French fries

A second study the same year looked at the most ordinary sequence imaginable: clean your hands with sanitizer, take the receipt, eat a few fries.

Sanitizers contain ingredients designed to help things pass through skin. When volunteers held receipt paper right after using one, BPA moved onto their hands quickly, then onto the fries, and their blood levels of active BPA rose within about 90 minutes. Holding the same paper with dry hands transferred far less.

That is the whole reason the slide says wash, don’t sanitize. Soap and water after an errand takes the residue off. Sanitizer, followed by a snack, does the opposite.

Cashiers, and the swap that wasn’t much of a fix

If anyone was going to show it, it would be the people handling receipts all shift. A 2016 study of 77 cashiers found that those working with BPA receipts had higher urinary BPA after work than people in other jobs. Cashiers using paper made with BPS, a close chemical cousin, saw their BPS levels climb over the course of a shift.

That second part matters. As BPA got a bad reputation, a lot of paper quietly switched to BPS and similar compounds. Lab research suggests BPS is hormonally active too. Paper labeled “BPA-free” is not automatically paper you want on your hands all day.

Europe took a firmer line. Since January 2020, thermal paper sold in the EU can’t contain more than 0.02% BPA by weight. The US has no federal equivalent.

Five habits, all free

None of this requires a new product. It is a handful of small defaults that add up.

1. 1
   Say no thanks

   Most stores do not need to hand you a receipt. If you do not need it for a return, skip it.

2. 2
   Ask for it by email

   Digital receipts carry no coating. Most big chains offer them at the register or in their app.

3. 3
   Keep receipts away from kids

   Little hands go straight to mouths. Hand them a crayon instead.

4. 4
   Wash with soap after errands

   Plain soap and water, especially before eating. Skip the sanitizer right before you touch paper or food.

5. 5
   Keep thermal paper out of the recycling

   Coated receipts can carry bisphenols into recycled paper products. They belong in the trash.