BPA, the next aluminum. Remember, anything in too great a quantity is BAD. Don't be stupid and boil water in your Nalgene, don't scrub it in strong acids or alkali solutions with steel wool, and don't autoclave it.

Check the archives, there is plenty there about why these claims are best described with a pronoun that gets frowned on around here. (Not suitable for small ears.)

BTW, welcome new guy.