Making “Greener” Chewing Gum

Chewing gum seems like a fairly innocuous substance—until you step on it or sit on it or get it on clothing or flooring. Or until you are faced with removing it from sidewalks and public places. The problem in Britain and Ireland is so bad that national and local governments have seriously considered a chewing gum tax. The cost of a comprehensive cleanup in Westminster City in London is estimated to be at least £10 million.

Modern chewing gum is made with a synthetic rubber, polyisobutylene, which not only makes it elastic, but also contributes to the obstinate, sticky quality. The gum removal industry is fiercely competitive. Several brands of steam cleaners are chewing gum–specific, and franchises for gum removal are available nationwide. Solvents to remove chewing gum are widely available, but they typically come in small aerosol or pump spray containers with warnings to wear gloves and eye protection.

The race to find a nonadhesive, biodegradable chewing gum is on. Revolymer in Great Britain has patented a low-adhesion chewing gum polymer that can be used in existing manufacturing processes. The company produces its own gum, Rev7, and offers the technology to other companies. According to its Web site, “in tests using mild agitation in water [the Revolymer polymer] fully disintegrate[d] into a fine powder within 6 months.” The chewing gum is reported to be easily removed from most fabrics and pavements (http://www.revolymer.com/removable_gum).

The Consorcio Chiclero, a consortium of 56 cooperatives in Mexico, is cultivating one of the oldest substances used for chewing gum, latex from Chicozapote trees (Manilkara zapota), to create Chicza, the “world’s first certified organic, 100% natural, biodegradable chewing gum”. When Chicza was launched in Britain in 2009, it was greeted enthusiastically by local governments and environmentalists. When the chewing gum dries, it becomes nonadhesive (i.e., it can be easily removed) and will disintegrate into a powder within 6 months (www.chicza.com).

The latest news about nonadhesive chewing gum comes from University College Cork (Ireland). In early November, the university announced that Elke Arendt and her research team at the School of Food and Nutritional Sciences developed and patented a nonstick, biodegradable chewing gum from cereal proteins. Professor Arendt says that their product tastes and feels like the synthetic products, but it safely dissolves in your mouth after 45 minutes. Tossed-out gum is easily picked up or swept away. Although the manufacturing technology for this gum is completely different from current processes, several companies are interested in its possibilities.

In the near future, it may be impossible to stick your chewing gum on the bedpost, the underside of the desk or chair, or anywhere else.