And glass, most of it containers and packaging, accounts for more than 5%.

Easily collected and recyclable indefinitely, glass and some metals, particularly aluminium, are some of the most efficient materials to recycle.

Recycling aluminium saves up to 95% of the power needed in the energy-intensive process of smelting new aluminium, and used glass melts at a temperature lower than that needed to produce new glass, so again uses less energy.

But only 27% of US waste aluminium and 23% of its glass is recovered for recycling – compared with 45% of its paper.

Of about 100 billion drinks containers shipped in the US each year, around three-quarters are aluminium and glass.

But, while higher proportions of aluminium cans and glass bottles are recycled than other products made of the same materials, recycling rates for both actually fell slightly in the late 1990s.

According to National Soft Drinks Association research, in 2000, nearly two thirds of aluminium cans were recycled - this is more than the UK’s 42%, but a long way below the 91% rate in Switzerland and Finland, and 86% in Sweden.

The role of glass as a material in the US is also declining - the amount in waste has decreased slightly since 1990. Green groups have mourned the demise of the refillable glass bottle – which accounted for virtually all drinks containers in 1947, but only 1% in 2000, and is still widely used in developing countries.

The decline of localised bottling and doorstep milk deliveries, together with reduced transport costs and cheaper, disposable alternatives, has meant the end of this practice which simply kept most drinks containers out of the waste stream altogether.

However, so-called “Bottle Bill” legislation is in force in 10 states, requiring manufacturers to include in the price of a product a deposit refundable when the container is returned.

The soft-drinks industry says this is neither consumer-friendly nor cost-effective. But campaign groups say it boosts recycling dramatically, claiming that those 10 states recycle more bottles and cans than all the other 40 states put together.