"After concerns mounted about bisphenol A, a hormone-mimicking chemical lacing many cash-register receipts, Wisconsin-based Appleton Paper has begun incorporating tiny red fibers in its thermal receipt paper to show that it is BPA-free."
Janet Raloff, who broke the original BPA-receipts story, reports for Science News November 8, 2010
SEE ALSO:
"Chemicals in Fast Food Wrappers Show Up in Human Blood" (ENS)
Source: Science News, 11/09/2010