The problem with plastics

The problem with plastics 

Plastics are carbon-based polymers (long-chain molecules that repeat their structures over and over) and we make them mostly from petroleum. They're incredibly versatile—by definition: the word plastic, which means flexible, says it all. The trouble is that plastic is just too good. We use it for mostly disposable, low-value items such as food-wrap and product packaging, but there's nothing particularly disposable about most plastics. On average, we use plastic bags for 12 minutes before getting rid of them, yet they can take fully 500 years to break down in the environment (quite how anyone knows this is a mystery, since plastics have been around only about a century).

Getting rid of plastics is extremely difficult. Burning them can give off toxic chemicals such as dioxins, while collecting and recycling them responsibly is also difficult, because there are many different kinds and each has to be recycled by a different process. If we used only tiny amounts of plastics that wouldn't be so bad, but we use them in astounding quantities. In Britain alone (one small island in a very big world), people use 8 billion disposable plastic bags each year. If you've ever taken part in a beach clean, you'll know that about 80 percent of the waste that washes up on the shore is plastic, including bottles, bottle tops, and tiny odd fragments known as "mermaids' tears."

Making better plastics

Ironically, plastics are engineered to last. You may have noticed that some plastics do, gradually, start to go cloudy or yellow after long exposure to daylight (more specifically, in the ultraviolet light that sunlight contains). To stop this happening, plastics manufacturers generally introduce extra stabilizing chemicals to give their products longer life. With society's ever-increasing focus on protecting the environment, there's a new emphasis on designing plastics that will disappear much more quickly.

• Broadly speaking, so-called "environmentally friendly" plastics fall into three types:
• Bioplastics made from natural materials such as corn starch
• Biodegradable plastics made from traditional petrochemicals, which are engineered to break down more quickly
• Eco/recycled plastics, which are simply plastics made from recycled plastic materials rather than raw petrochemicals.

BIO Plastics

The theory behind bioplastics is simple: if we could make plastics from kinder chemicals to start with, they'd break down more quickly and easily when we got rid of them. The most familiar bioplastics are made from natural materials such as corn starch and sold under such names as EverCorn™ and NatureWorks—with a distinct emphasis on environmental credentials.