What are Bisphenols and Phenols?
Bisphenols are chemical compounds historically used in thermal coatings to develop the printed image under heat. The most common were BPA (bisphenol A) and BPS (bisphenol S). Both belong to the broader group of phenolic compounds, some of which have raised environmental and health concerns due to their persistence and potential endocrine effects.
Why They Were Used
In traditional direct thermal materials, bisphenols acted as colour developers. When heat from the printer head was applied, these compounds reacted with other components in the coating to form the dark printed image. This provided sharp print contrast and fast response times, but the chemistry came under review as awareness of bisphenols grew.
Regulation and Reformulation
The use of BPA in thermal paper was restricted in the EU and UK from 2020, driving significant reformulation. Some products switched to BPS as a drop-in replacement, while others moved to completely new bisphenol-free chemistries. These newer coatings achieve high image stability and print quality without bisphenols or phenols.
Modern Alternatives
At North & South Labels, our Direct Thermal (DT) range includes two main grades:
- DT Eco — an economical uncoated material that is BPA-free, suitable for general-purpose applications where moderate image life is sufficient.
- DT Top-coated — a premium grade produced without bisphenol chemistry, making it BPA-, BPS- and phenol-free as standard, with enhanced resistance to heat, light and handling.
Choosing the Right Option
If your application involves regulated environments such as healthcare, food contact or long-term storage, we recommend specifying Top-coated Direct Thermal for maximum chemical compliance and image durability. For short-term logistics or general use, Eco grade materials remain a cost-effective, BPA-free solution.
