Consumer electronics products should be greener, says environmental campaign group Greenpeace International.

In its 'Green Electronics: the search continues' report, the group evaluated 50 products from 15 companies, identified by the manufacturers as their most environmentally friendly models, but found that none of them performed well against all criteria.

Greenpeace discovered that fewer of the products contained PVC (polyvinyl chloride) plastic and other hazardous chemicals, compared to those tested a year ago. In the past, it has campaigned vigorously against the use of toxic materials in products.

One thing that changed for the better in 2008 was the increasing use of LED displays, which avoid the use of backlights containing mercury, and are also more energy efficient, Greenpeace said. Companies are also using recycled materials, for example in TV and monitor casings, and are increasing the volume of old products that they take back for recycling.

Despite all these improvements, the best-rated product, Lenovo's L2440x computer monitor, only scored 6.9 out of 10. The second-placed product was also a monitor, Fujitsu Siemens Computers' ScenicView P22W-5 Eco, with 6.33.

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Lenovo's weakest link was energy use. It lost points for not tracking the energy used to manufacture the monitor, and could have done better by providing more information about the monitor's energy-saving mode. It could have scored an easy point by fitting a real off switch that physically cuts all current. Instead, like many devices, it has a standby switch that contributes to so-called 'phantom' power consumption by maintaining power to some of its circuitry even when it is apparently turned off.

Lenovo also lost marks for exploiting exemptions in the European Union directive on the reduction of hazardous substances (RoHS), which allows companies to continue using banned toxic chemicals in their products in certain circumstances.

Other companies have shown that they can do better in the categories where Lenovo fell down. If a manufacturer were to follow the best practices of any of the companies seen by Greenpeace in each category (energy use, reduction of toxic chemicals, recycling and so on), then it would score 8.6 out of 10.

Lenovo was also the top scorer in the desktop computer category - although that business unit clearly still has much to learn from the monitor division, as its ThinkCenter 58/M58p only scored 5.88 out of 10, narrowly beating Fujitsu Siemens Computers' Esprimo E7935 E-Star 4, which scored 5.73.

In the laptop category, Lenovo's X300 only made third place with 4.68 points, behind the Toshiba Portege R600 at 5.57 points and the HP Elitebook 2530p, which scored 5.48.

Nokia's 6210 Navigator was the greenest smartphone tested by Greenpeace, scoring 5.2 out of 10. Apple declined to take part in the study, so Greenpeace can't tell us how the iPhone 3G would have rated.

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It's not only the actual product, manufacturers need to improve when it comes to being environmentally friendly, they need to tackle consumer opinions too. A recent survey by the Consumer Electronics Association found that 65 percent of consumers think manufacturers overstate their green credentials, while 40 percent of them are confused by manufacturers' claims.

See also: Half of TV makers fail recycling test