By Andy Darnley

Glass can be found everywhere, from one’s kitchen at home to classrooms at school. Products made of glass are so common that they are often taken for granted. Some of the glass that people use is easily disposable, and unfortunately, if it ends up in trash cans, it ultimately ends up in landfills, where it is estimated that it will take a million years to decompose. However, glass jars and bottles are 100 percent recyclable. Unlike many other recyclable items, glass can be recycled repeatedly without a loss of quality or purity. Recycling glass not only saves space in landfills, but it also saves natural resources such as soda ash, sand, and limestone and reduces emissions that contribute to global warming and pollution. It also takes less energy to make recycled glass products than new glass. In states with bottle bills, people can even make a small amount of money when they return bottles to the appropriate recycling centers or retail stores. But how exactly is glass processed and recycled? Understanding the recycling process provides a better appreciation of the products that come from recycled glass.

Glass recycling is a process that begins with the people who buy and use it. For most people, a majority of their recycling takes place at home with the help of curbside recycling programs, but people are often able to take their glass to local drop-off sites or recycling centers as well. To prevent residents from putting their glass items in the trash, curbside programs typically provide some type of bin that people can fill with recyclable items for pickup on specified days of the week. Container glass may be clear or colored bottles like those used for alcoholic beverages or jars that are used for baby food, pasta sauce, and other food products.

Most often, curbside pickups will not accept items such as drinking glasses, cookware, vases, light bulbs, and mirrors. These items act as contaminants in a load of recyclable glass, as they are made using materials such as plastic and lead. In addition, their different chemical compositions mean that they melt at different temperatures than those used in the recycling process for jars and bottles. As a result, they will need to be recycled separately, as they can compromise the structural integrity of recycled container glass. It’s important for families to check with their local recycling centers to find out if and where glass other than container glass can be recycled. Before recycling container glass, it should be rinsed so that there’s no liquid, food, or other contaminants remaining inside. In many cases, labels do not need to be removed.

At recycling facilities, glass jars and bottles are sorted. A common first step in recycling glass is to break it into shardsand remove any lids, caps, or other metals. This is often done using a machine with large magnets. It is then sorted by people, machines, or both so that the glass is free of any impurities such as stones. It is also optically sorted according to color so that all clear glass, for example, is recycled together. The recycled glass is then cleaned to ensure that there’s no remaining food or other impurities, and it is crushed into tiny pieces called cullet. Cullet goes through another screening process that removes any remaining ceramic, plastic, or bits of paper such as labeling, and it is then delivered to glass manufacturers.

The cullet is mixed with natural materials normally used to make glass before it is melted in a large furnace. The melted glass is molded or blown to form the desired shapes for new bottles or jars. The completed and cooled jars are then inspected for quality and are sent for their intended use. While recycled glass cullet is commonly used for making bottles and other glass containers, some cullet may also be used in the creation of other items that people encounter on a daily basis. This includes fiberglass insulation, countertops, and even bricks and flooring.