A bottle is a container with a neck and mouth for holding liquids. Bottles are typically made of glass or plastic and have a wide range of uses, from carrying drinking water to storing medicine or shampoo. Most bottles are used for liquids, but some are also used to preserve food in jars and to hold chemicals or other materials. Regardless of their use, most bottles have the same basic features: a neck and mouth, a body with a capacity for holding liquids, and a closure (cap or cap).
Bottles are the most common item found in ocean pollution. They are also the most commonly recycled item, but only if they are properly collected and sent to a recycling plant. In places with poor waste management, or where recycling facilities are limited in their ability to process certain types of bottles, they can end up on the beach or in the sea. As they degrade, they are broken down into microplastics that can harm marine life.
The earliest bottles were likely made from glass, but the invention of synthetic polymers in the 1940s allowed for the manufacture of a lightweight, strong, and versatile bottle material. A popular example is PET, or polyethylene terephthalate. It is produced by reacting petroleum hydrocarbons with ethylene glycol and terephthalic acid to create long molecular chains that can be molded into bottles. This plastic is highly recyclable, and it can be used for food or beverage containers.
Most modern plastic bottles are manufactured using either injection or extrusion blow molding. The resin identification code 2 indicates that a bottle is made from high-density polyethylene, which is durable and has an efficient moisture barrier. It is a good choice for bottles that will be exposed to a variety of environmental conditions, including exposure to sunlight and chemicals, and it is resistant to fats and oils.
Glass water bottles are another good alternative to plastic, and they can be recycled many times over.1 However, they do not work well in hot environments and can break easily if dropped or crushed. In addition, it is important to store glass water bottles away from household chemicals and cleaning products as they can leach harmful substances into the water.
Whether you are looking for ways to reduce your bottle consumption or find new solutions for what to do with all the empty ones, the world is awash in ideas and initiatives. As you take in the images of our polluted oceans, try to identify a familiar object—a plastic bottle, perhaps—and consider how it came to be there. It is a bit of a riddle that such a hard and beautiful material should become a symbol of human environmental degradation. But maybe that is the point: a reminder of what we have done and what we could do better in the future.