What do Whole Foods, the United States Postal Service, McDonald’s and WalMart have in common?

They all tested positive for measurable levels of the controversial plastics chemical bisphenol A in an unlikely place: paper receipts.

The Environmental Working Group conducted a study and found endocrine-disrupting BPA in 40 percent of 36 printed receipts collected from fast food restaurants, big retailers, grocery stores, gas stations and post offices in seven states and the District of Columbia.

Major retailers using BPA-containing receipts in at least some outlets included McDonald’s, CVS, KFC, Whole Foods, Walmart, Safeway and the U.S. Postal Service. Receipts from some major chains, including Target, Starbucks and Bank of America ATMs, issued receipts that were BPA-free or contained only trace amounts.

Safeway supermarket receipts had the highest BPA levels. Safeway receipts had 3 of the top 6 highest overall BPA levels. A store in the District of Columbia had the greatest total estimated mass of BPA (41 milligrams). A Berkeley, CA Safeway had the highest concentration of BPA relative to the paper mass (2.8 percent of the receipt weight). Safeway was one of two retailers that had detectable BPA in all three store locations sampled.

The receipt for a McDonald’s Happy Mealâ„¢ purchased in Clinton, Conn. on April 21, 2010 had an estimated 13 milligrams of BPA. That equals the amount of BPA in 126 cans of Chef Boyardee Overstuffed Beef Ravioli in Hearty Tomato & Meat Sauce, one of the products with the highest concentrations of BPA in EWG’s 2007 tests of canned foods.

The USPS has said they stopped purchasing BPA-coated thermal receipt paper since September 2009. But it’s possible many locations and sub-stations still have old stock they may be using.

Whole Foods has spoken out on the Twitter account, saying, “we are working with our stores to identify non-BPA thermal papers that are compatible with our store systems.” They will have additional stores transition this fall to non-BPA registers.

Tips to reduce BPA exposure in receipts:

  • Minimize receipt collection by declining receipts at gas pumps, ATMs and other machines when possible.
  • Store receipts separately in an envelope in a wallet or purse.
  • Never give a child a receipt to hold or play with.
  • After handling a receipt, wash hands before preparing and eating food (a universally recommended practice even for those who have not handled receipts).
  • Do not use alcohol-based hand cleaners after handling receipts. A recent study showed that these products can increase the skin’s BPA absorption (Biedermann 2010).
  • Take advantage of store services that email or archive paperless purchase records.
  • Do not recycle receipts and other thermal paper. BPA residues from receipts will contaminate recycled paper.
  • If you are unsure, check whether paper is thermally treated by rubbing it with a coin. Thermal paper discolors with the friction; conventional paper does not.