Do you know what the number stands for?
Did you guess that it's just for recycling?
Then you are WRONG !!!!!!
THE NUMBER TELLS YOU THE CHEMICAL MAKE UP OF THE PLASTIC.....
1) Polyethylene terephalate (PET)
2) High density polyethylene (HDPE)
3) Unplasticised polyvinyl chloride (UPVC) or Plasticised polyvinyl chloride (PPVC)
4) Low density polyethylene LDPE
5) Polypropylene (PP)
6) Polystyrene (PS) or Expandable polystyrene (EPS)
7) Other, including nylon and acrylic
What you aren't told is that many of the plastics used are toxic and the chemicals used to create a plastic can leach out of the plastic and into the food / drink.
Think about it, how many times have you or a friend said "I don't like this, it taste like the plastic bottle ..... "
THAT'S BECAUSE YOU ARE TASTING THE PLASTIC
The WORST ONES are Nos: 3, 6, and 7 !!!
DO NOT USE THESE NUMBERS if stated at the bottom of the bottle) !!!
Check out this chart that breaks down the plastic, its uses and chemical makeup
(I find #7 a little scary)
Reusing plastic bottles by refilling them is NOT a good idea. WATCH THIS VIDEO: http://video.wnbc.com/player/?id=238518
Microwaving plastic containers affects the chemical make up of the plastic, allowing the chemical substances to destabilize and leach out more quickly into the food you are reheating. You can check out this article that ran in the Wall Street Journal:
http://www.mindfully.org/Plastic/Microwave-Health-Problems.htm
Lists the information as: overblown with a grain of TRUTH
READ the FULL 3 pages of the article!
http://urbanlegends.about.com/library/bl-microwave-dioxin.htm
AVOID re-using plastic bottles RIGHT AWAY !!!