A water bottle is a container that is used to hold liquids, mainly water, for the purpose of transporting a drink while travelling or while otherwise away from a supply of potable water.
Water bottles are usually made of plastic, glass, metal, or some combination of those substances. In the past, water bottles were sometimes made of wood, bark, or animal skins such as leather, hide and sheepskin. Water bottles can be either disposable or reusable. Disposable water bottles are often sold filled with potable water, while reusable bottles are often sold empty. Reusable water bottles help cut down on consumer plastic waste and carbon emissions..
Types
Single-use plastic
Sales of single-use, pre-filled plastic water bottles have increased almost every year for more than a decade. In 2011, greater than US$11 billion was spent on bottled water products in the United States alone. The International Bottled Water Association (IBWA) states that people are increasingly relying on water bottles for convenience and portability.
In some countries with low-quality tap water, citizens also use bottled water (including in family-size containers kept in the home) for health reasons. For example, as of 2010, Mexico had an average 8 percent increase per year in bottled water purchases and consumed approximately 13 percent of the world's total of bottled water. Mexican citizens drink more bottled water than people of any other country, at an average of 61.8 gallons per person each year – more than twice the rate of US per capita consumption. The increase in the use of single-use personal plastic water bottles has contributed markedly to the country's litter problem, though the increase in the popularity of bottled water has come with a decrease in the growth rate of consumption of soft drinks (which pose health risks in excessive quantities, as well as the same littering problem).
Reusable plastic
Multi-use water bottles can be made from high-density polyethylene (HDPE), low-density polyethylene (LDPE), copolyester, or polypropylene. They all offer the advantage of being durable, lightweight, dishwasher-safe, and BPA-free. The main difference between each type of water bottle is the flexibility of the material. Copolyester and polypropylene offer the greatest rigidity; HDPE retains some flexibility; LDPE (most commonly associated with collapsible, squeeze bottles) is highly flexible.
Metal
Metal water bottles are growing in popularity. Made primarily from stainless steel or aluminium (aluminum), they are durable and retain less odor and taste from previous contents than most plastic bottles. But these can sometimes impart a metallic taste. Metal bottles thus often contain a resin or epoxy liner to protect contents from taste and odor transfer or corrosion. Although most liners are now BPA-free, older and less expensive models can contain BPA. Glass liners may also be used .
It is not recommended to fill aluminium bottles with acidic liquids (e.g. orange juice), as this could cause aluminium to leach into the contents of the bottle. Depending on the type of source material and manufacturing process behind a stainless steel bottle, trace amounts of minerals can leach into contents from this type of bottle as well. Stainless steel bottles that do not contain a liner have been known to transfer a rusty taste and odor to contents. Bottles made with food-grade stainless steel (grade 304, also known as 18/8) do not transfer taste or odor.
Metal (especially steel) water bottles can be heavier than their plastic counterparts. Single-walled metal bottles readily transfer temperature of contents to external surfaces, which makes them unsuitable for use with unusually hot or cold liquids. Double-walled metal bottles are insulated to keep cold liquids cold and hot liquids hot, without the external surface being too hot or too cold. Because double-walled bottles have more metal in them, they are more expensive. They are typically vacuum-insulated, but some may have a solid or gel insulation between the metal walls.
Glass
Glass flasks have been used since ancient times, though were not common until the Early Modern period when consistent, bulk manufacturing of glass products became easier. Because they are completely recyclable, are BPA-free, and do not retain and transfer taste or odor, glass water bottles are becoming a popular choice again for many consumers concerned about their health.