The paper receipts handed out at checkout counters may seem harmless, but many contain substances known as “forever chemicals” that have been linked to a range of health concerns.

These man-made chemicals have been associated with certain cancers, hormone disruption, reproductive problems, metabolic disorders, and abnormal fetal development.

In response to growing health and environmental concerns, Swiss scientists have developed a new type of receipt paper made from wood-based materials that eliminates the need for these harmful chemicals. The innovation not only reduces potential health risks but also supports sustainability by using renewable resources.

Traditional thermal receipt paper relies on a heat-sensitive process that uses colorless dyes to create dark text without ink or toner. The most common chemical developers used in this process are bisphenol A (BPA) and bisphenol S (BPS). These chemicals have been used for decades and are known to leach into soil and water. They have also been detected in people who regularly handle receipts, such as retail workers.

Finding safer alternatives to bisphenols has proven challenging. Thermal paper must meet several requirements: it must print clearly, remain stable during storage, work at specific temperatures, and be affordable to produce. Regulators and manufacturers have searched for replacements, but progress has been slow because less toxic materials must still perform reliably without discoloration or degradation, according to a news release.

Researchers at the EPFL Polymers Laboratory and the Swiss Centre for Applied Topology believe they have found a solution. In a study published in Science Advances, the team reported developing thermal paper coatings made from lignin, a natural component of wood, combined with a sensitizer derived from plant sugars.

“We have developed thermal paper formulations — which are commonly found in daily products like cash receipts, package labels, airline tickets, and more — made from plant-based molecules that have very low or no toxic signatures,” said Jeremy Luterbacher of EPFL.

The researchers focused on lignin because it naturally contains chemical groups capable of acting as color developers. When heated, the lignin-based coatings produced clear printed images with color density levels suitable for commercial thermal paper. The coatings also proved durable, remaining stable when stored near a window for months, with printed logos still readable after a year.

While image contrast was slightly lower than that of fully optimized commercial paper, performance was comparable to BPA-based thermal paper currently in use.

Safety testing showed a major advantage. The lignin-based developers exhibited much lower estrogen-like activity than bisphenols, and the sugar-based sensitizer showed no estrogenic or toxic effects under the conditions tested.