Scientists develop non-toxic thermal paper using wood-based coating

Researchers at EPFL have developed a non-toxic thermal paper coating derived from wood-based materials, specifically lignin and a plant sugar-based sensitizer. Lignin, a major component of wood, was extracted using a controlled method called sequential aldehyde-assisted fractionation to produce light-colored polymers suitable for high-quality printing. The sensitizer, diformylxylose, is derived from xylan, a plant cell wall sugar, replacing petroleum-based chemicals. This bio-based formulation aims to substitute traditional thermal paper chemicals like bisphenol A (BPA) and bisphenol S (BPS), which are known hormone disruptors and environmental contaminants. The lignin-based coatings demonstrated clear image quality with color density comparable to commercial BPA-based thermal papers and maintained functionality after months of storage and a year of readability. Although image contrast is not yet fully optimized, the performance is promising. Safety tests revealed that the lignin developers exhibit estrogen-like activity significantly lower (by two to four orders of magnitude) than BPA