Bottled water is drinking water packaged in plastic or glass containers. The dominant form is water packaged in new Polyethylene terephthalate bottles and sold retail. Another method of packaging is in larger high-density polyethylene plastic bottles, or polycarbonate plastic bottles, often used with water coolers.
The major criticism of bottled water concerns the bottles themselves. Individual use bottled water is generally packaged in Polyethylene terephthalate (PET). According to a NAPCOR study, PET water bottles account for 50% of all the PET bottles and containers collected by curbside recycling, and the recycling rate for water bottles is 23.4%, an increase over the 2006 rate of 20.1%. PET bottled water containers make up one-third of 1 percent of the waste stream in the United States.
The International Bottled Water Association also reports that the average weight of a plastic bottle water was 13.83 grams in 2007, compared to 18.90 grams in 2000, representing a 26.7% decline. Pepsi-Co has since introduced a bottle weighing 10.9 grams and using 20 percent less plastic, which it says is the lightest bottle of its kind that is nationally distributed.
An estimated 50 billion bottles of water are consumed per annum in the US and around 200 billion bottles globally.
Bottled water processed with distillation or reverse osmosis lacks fluoride ions which are sometimes naturally present in ground water. The drinking of distilled water may conceivably increase the risk of tooth decay due to a lack of this element.
According to a 1999 NRDC study, at least 22 percent of brands tested, at least one sample contained chemical contaminants at levels above strict state health limits. Some of the contaminants found in the study could pose health risks if consumed over a long period of time. However, the NRDC report conceded that "[m]ost waters contained no detectable bacteria, and the levels of synthetic organic chemicals and inorganic chemicals of concern for which were tested were either below detection limits or well below all applicable standards." Meanwhile, a report by the Drinking Water Research Foundation found that of all samples tested by NRDC, "federal FDA or EPA limits were allegedly exceeded only four times, twice for total coliforms and twice for fluorides."
The rate of total dissolved solids is sometimes 4 times higher in bottled mineral waters than in bottled tap ones. High amounts of calcium in mineral bottled waters for example mean that a daily and excessive consumption may result in hypercalcemi, which highly increases the risk of kidney or gallstones.
Another study, conducted by the Goethe University at Frankfurt found that a high percentage of the bottled water, contained in plastic containers were polluted with estrogenic chemicals. Although some of the bottled water contained in glass were found polluted with chemicals as well, the researchers believe some of the contamination in the plastic containers may have come from the plastic containers themselves.