If you still use the plastic bottles it is important to know the meaning of the number inside the triangle which is located on the bottom of the bottles.
The numbers range from 1 to 7 and indicate the type of plastic with which the container is made.
Pet is an abbreviation for "polyethylene terephthalate". This type of plastic is used in the bottles and trays disposable. These containers are to be used only once because the re-use increases the risk of bacterial contamination.
Hdpe "high density polyethylene", is used for more rigid containers such as yogurt and plugs. The bottles come with this number were considered more secure from external contamination.
PVC "polyvinyl chloride" used for packaging and for some oil bottles.
Ldpe mainly used in the production of bags and envelopes. The European Food Safety Authority (EFSA) with a 2017 study demonstrated non-toxicity if contamination remains within the set limits.
PP "polypropylene" is mainly used for bottles and cans
Ps "polystyrene" (or polystyrene) used for packaging and disposable plates and cups.
Others in this category are all plastics are not listed above and containers made of plastic combinations listed above.
In conclusion, it is better to replace the plastic bottles with those of steel or with the tap water. Environment, health and wallet will thank!