Should you worry about BPA in reverse osmosis tanks?
Because of the widely publicized presence of BPA in some plastic products, the public has developed a general suspicion of all plastics as a source of BPA. Actually, the plastic products that contain BPA are mainly the hard, shatter-resistant, usually clear water bottles as well as baby bottles and a few other plastic containers. You normally will not find BPA in plastics like polypropylene and polyethylene. BPA is not one of the materials used in preparing these plastics.
If a product is NSF certified (certified to ANSI/NSF standard 58), the certifying agency has scanned the product for BPA. If the product contains BPA, it will fail the extraction test and will not be certified.
The materials in high quality RO tanks that touch the water are stainless steel (the spout only), polypropylene (the liner in the chamber that holds the water), and butyl (the bladder that holds air and pushes the water out of the tank). The butyl (aka chlorobutyl) bladder material in high quality tanks is specially cured so that it will not put out bad tastes or contaminants.
There are lots of things that contaminate food and water that we should worry about. but reverse osmosis tanks aren’t one of them.