BPA is the chemical Bisphenol A which is widely used to make plastics and resins – not least those used for containers that store food and beverages, such as water bottles and baby feeding bottles.

BPA is thought to disrupt hormones by affecting the endocrine system, which releases hormones throughout the body particularly sex hormones – which might affect puberty or the menopause – or cause cancers such as breast cancer, heart disease, genital birth defects and a number of other human illnesses

There is a growing call to stop manufacturing plastics with BPA and thankfully there are much less hazardous alternatives. But like the tobacco industry before it, the Chemical industry is fighting this tooth and nail.

https://www.motherjones.com/environment/2014/03/tritan-certichem-eastman-bpa-free-plastic-safe