[By Zhou Tao/Shanghai Daily]

Plastics are everywhere.

Whether used to store leftovers, keep hospital equipment sterile, or insulate a home, plastics are unmatched for their adaptability, durability, and low cost.

Given their boundless benefits, it is unsurprising that plastics have replaced traditional materials in many sectors - for example, steel in cars, paper and glass in packaging, and wood in furniture.

As a result, annual plastics consumption worldwide has increased from five million tons in the 1950s to around 280 million tons today.

Roughly half of plastic products, such as packaging, are intended for one-time, short-lifespan (less than six months) applications prior to disposal.

Given that most of these items are not biodegradable, and are not recycled, plastics waste is building up - with serious environmental consequences.

While governments have begun to implement new (and often quite strict) regulations aimed at managing plastics waste - for example, China banned lightweight plastic shopping bags in 2008 - they are inadequate to address the world's growing plastics-waste problem.

Moreover, most plastic products are made from so-called "petroleum-based commodity thermoplastics."

Non-renewable resource

Given that a non-renewable resource forms the basis of many plastic products - most of which will not last long - current plastics usage patterns are not sustainable.

Closed-loop recycling, in which plastics waste is used to make another product, thus carries significant environmental benefits, such as reduced energy and oil consumption.

But the process of separating the petroleum-based recyclable plastics from other kinds of plastics and solid waste is difficult, costly, and labor-intensive, so only a small proportion is recycled.

In 1988, the United States Society of Plastics Industry (SPI) developed a coding system in which each kind of resin is labeled with a number, 1-7, to facilitate sorting. The system has also been used elsewhere, including in Canada and Switzerland, but has not been adopted worldwide and is still confusing to some consumers.

If consumers knew to collect and separate household plastics based on their number, the resulting boost to recycling efforts would demonstrate to government and industry the viability of a more sustainable approach, reduce exposure to rising oil prices, and support growing global demand for plastics.