well plastic bottles contain carcinogenic compounds? Well maybe when burnt.
Oh as for the bacteria I see what you mean but end of the day as long as you are sensible I doubt you will have a problem.
In a nutshell, the plastic (called polyethylene terephthalate or PET)used in these bottles contains a potentially carcinogenic element(something called diethylhydroxylamine or DEHA). The bottles are safe for one use only; if you must keep them longer, it should be or no more than a few days, a week max, and keep them away from heat as well.
Repeated washing and rinsing can cause the plastic to break down and the carcinogens can leach into the water that YOU are drinking.
Better to invest in water bottles that are really meant for multiple uses.
This is not something we should be scrimping on. Take care.
I'm not taking any chances anyway, Sam. I threw all my plastic bottles out and bought the ones that are meant for re-use.