Oral
Abstract
Research summary supplied by the authors
Bisphenol A (BPA) has been identified as an endocrine disruptor. The endocrine system covers multiple functions within the body through a series of feedback loops that help with the regulation of organs through the secretion of hormones. As such, any chemicals which are endocrine disrupting can have widespread impact within the body or the natural environment. Despite this, over 1,000,000 tonnes / annum of BPA are produced, imported, and used within the EU. Also of concern are related substances to BPA, in particular Bisphenol S (BPS) and Bisphenol F (BPF) which, while less evidence exists, have had endocrine disrupting properties identified in Zebra fish, rats, mice and humans. Both BPS and BPF are often found in leather, BPS is the starting material from which sulphone replacements syntans are produced, BPF is a byproduct in the production of phenolic syntans. Due to the environmental concerns, the European Union is proposing restrictions in total bisphenol content in leather of 10 mg/kg, with a higher limit of 500 mg/kg between 2025 and 2030 making the presence of bisphenol compounds in leather a compliance as well as an environmental issue. Despite the proximity of these new regulations in the EU, there is little information in the public domain related to their presence in leather chemicals and their transference into leather and there is an urgent need for research in this regard. Here we have applied high performance liquid chromatography (HPLC) to study bisphenol content in replacement syntans and their incorporation into leather. Significant variations in BPS and BPF content were observed. Sulphones contained between 207 and 41,200 mg/kg BPS, though most had concentrations above 6,000 mg/kg. Phenolic syntans contained between 240 and 563 mg/kg. Bisphenol contents were higher in belly areas compared with those measured at the official sampling position (OSP) by 12 – 14%, questioning the suitability of the OSP as a sampling position. A comparative trial of 4 separate approaches to leather processing was undertaken, it was demonstrated that final leather BPS and BPF concentration can vary depending on the point of application of the replacement syntan and other variations with up to 25 – 35% reduction of final leather bisphenol content achievable.