What is BPA and why should one be worried about it? Why should you use BPA free products? Research shows that BPA or bisphenol A can seep into products and beverages. Additional research suggests a possible link between BPA and increased blood pressure.BPA or bisphenol A,it has to do with its status as an endocrine disruptor, meaning that BPA can behave like naturally occurring hormones (estrogens, androgens, and thyroid hormones) in the body like. This can result in abrupt rise or fall in the secretion of these hormones.  So be careful, If a product isn't labeled as BPA free, it might prove to be harmful. Volume size: 1/2 gallon / 1.89 liter Cap size: 48mm Screw cap Bottle size: 5" Diam. x 9.75" Safety lock sports cap.