Bisphenol A (BPA) in thermal paper used for receipts
Background: Bisphenol A (BPA) is a proven endocrine disruptor and has been found in the urine of 95% of Canadians. Though the chemical has been banned for use in certain applications, it is still common in items such as thermal paper used for receipts because the compound is heat stable. This study aims to determine if the levels found in thermal receipt paper are high enough to pose a public health concern. Methods: Samples of thermal paper used for receipts were tested for BP A by soaking and incubating lOOmg of the paper in lOmL of methanol for 3 hours at room temperature, and then overnight at 4°C. The resulting methanol solution was then analyzed by using an HPLC (high performance liquid chromatography) system with fluorescence detection. Results: A total of 30 receipts were tested from various stores around the Lower Mainland, including retail stores and restaurants. Of the 30 samples, 13 tested positive for bisphenol A, and of those 13, the amount ranged from 0.124 to 871.17 mg BPA per kg paper. Using the provisional total daily intake (0.025mg/kg body weight/day) set by Health Canada in 1996, results indicate that there can be enough BPA present in a minimum of 2 grams of the paper to exceed the daily limit for a person weighing 70kg. However, the human body does not absorb all of the BPA it may come into contact with, nor does a person touch the entire surface of the paper; thus, more than 2 grams of thermal paper would be required to actually exceed the pTDI. Conclusion: Although the human body does not absorb all of the BPA it may come into contact with, thermal receipt paper can still be a significant source of BP A, especially for those who handle them frequently, such as cashiers. Public education on common sources of BP A, such as thermal receipts, would reduce exposure.