Are you guys aware that the triangle number under your water bottle actually means something? It tells us what type of material the plastic bottle was made of. And the recent studies suggested that the most popular hard, clear and durable plastic bottle that we used was made of Polycarbonate and one of the key components of this is the endocrine-disrupting bisphenol-A (BPA).
BPA can leach into the liquid and making the water toxic and can cause breast cancer in women or prostate cancer in men and some other illnesses. This bottle has numbered (3), (6) or (7) in the triangle. So, I would advice all my friends and family members to stop using any water bottle that has a number (3,6,7) under the bottle. The most common plastic bottle that we have seen everywhere has a number (7) in the triangle.
I guess the best re-usable water bottle would be one made from stainless steel as they don't leach any chemicals. But it can be expensive. So, the other alternative is to look for water bottles that contained number (2) (high-density polyethylene), (4) (low-density polyethylene) and (5) (polypropylene).
If not, just drink from the glass or coffee cup. Use glasses while at home and only use the plastic water bottles with number (2), (4) and (5) in the triangle while going out. Number (1) water plastic bottle is safe to use but it was not meant to be re-used.