hi does anyone know if the 12 baht 20 litre plastic drinking water bottles that are delivered to your door contain BPA chemicals

OP, I suspect that you'll likely have to be slightly more precise in your question to get an answer.

From the Wiki on BPA (Bisphenol A) here http://en.wikipedia.org/wiki/Bisphenol_A

In general, plastics that are marked with recycle codes 1, 2, 4, 5, and 6 are very unlikely to contain BPA. Some, but not all, plastics that are marked with recycle codes 3 or 7 may be made with BPA."^[28]

There are seven classes of plastics used in packaging applications.

Type 7 is the catch-all "other" class, and some type 7 plastics, such as polycarbonate (sometimes identified with the letters "PC" near the recycling symbol) and epoxy resins, are made from bisphenol A monomer.^[5][29]

Type 3 (PVC) also may contain bisphenol A as an antioxidant in plasticizers.^[5] This refers to "flexible PVC", but not for rigids such as pipe, windows, and siding.