Have you ever wondered what your computer is made of? You may not want to know. An analysis by Greenpeace of the chemicals contained in the components of five types of laptop computer revealed toxic flame-retardants and other harmful chemicals in some of them. In one of the computers, Greenpeace says it found harmful chemicals that the maker has publicly claimed to have eliminated from its products.

The findings highlight the challenges facing environmental regulators as they attempt to police the eradication of harmful chemicals from electronic goods. Failure by the regulators might not only put users at risk, but also mean chemicals might leach into groundwater beneath landfills, or contaminate people working in recycling plants where these machines end their lives.

Greenpeace found the toxic chemicals after analysing just a handful of the many hundreds of components inside each computer. Zeina Al-Hajj of Greenpeace says that the discovery of suspect chemicals in such a limited analysis of electronic goods reveals the magnitude of the task facing regulators as they work to enforce new rules on the use of many chemicals in goods, such as the European Union's Restriction on Hazardous Substances (RoHS) directive.

The laptop analysis was carried out at the Eurofins environmental testing lab in Galten, Denmark, and a Greenpeace lab at the University of Exeter, UK. The labs bought five new laptops made by Acer, Apple, Dell, Hewlett-Packard and Sony in March this year. The computers were then dismantled and analysed using various techniques, including X-ray spectroscopy to detect and quantify the presence of certain chemical elements in 40 components, including cooling fans, taken from each computer.

A selection of these samples were then submitted to combined gas chromatography and mass spectrometry to detect the presence of specific compounds. The analysts found that among the five computers, the Hewlett-Packard laptop had some of the highest levels (see Table) of a number of chemicals, including a substance called decabromodiphenyl ether (decaBDE), a flame retardant that the company claims to have removed from its product line some years ago.

Greenpeace stresses that its analysis is not a reflection on any of the manufacturers' entire product lines - and none of them has broken any law. However, the findings are at odds with information about Hewlett-Packard products that the company has placed on its website, which states: "HP eliminated the use of decaBDE many years ago and has no plans to reinitiate its use."

"That is quite shocking," says Jim Puckett of the UN's Basel Action Network in Seattle, Washington. The network monitors breaches of the Basel convention, which regulates the flow of hazardous waste from industrialised countries to developing nations. With the wide range of substitute chemicals available today, there ought to be alternative choices for manufacturers, he says.

"It's disappointing to see these results," says Zoe McMahon, HP's environmental manager for Europe. The company has not been deliberately misleading its customers, she says, and is taking the matter seriously. "Our policy hasn't changed. Several years ago we restricted a number of flame retardants," she says, including decaBDE. It's too early to say how this substance came to escape HP's testing procedures and end up in the laptop that was analysed but HP is working with its suppliers to investigate Greenpeace's findings, she says.

Apple Computer's MacBook laptop analysed by Greenpeace also contained a permitted flame-retardant, called TBBPA, at levels higher than in any of the other computers, says Kevin Brigden at the Greenpeace lab, who oversaw the testing. Apple Computer chose not to respond to Greenpeace's findings when asked for comment by New Scientist.

TBBPA, decaBDE and other brominated flame retardants (BFRs) were once used in many plastic components in electronic goods, but are now being phased out following concerns over their impact on human health and the environment. "Some BFRs persist in the environment and are able to bio-accumulate," Brigden says. Long-term exposure can interfere with brain development, or the endocrine system. One of the problems with these chemicals is that it is difficult to dispose of them through incineration without releasing highly toxic dioxins into the environment. Only the Sony laptop contained no BFRs (see Table).

Controversially, decaBDE is still permitted under the European Union's RoHS directive. It was originally banned but was reinstated after the makers objected to the EU, saying it was less hazardous than other BDEs. However, since commercial decaBDE contains about 3 per cent nonaBDE, which was banned when RoHS came into force on 1 July, the use of decaBDE will now in practice no longer be possible. None of the machines Greenpeace tested was breaking any law, however, because they were purchased in Europe before 1 July.

RoHS may be a European law, but its influence is being felt around the world. Even in the US, where (except in a few states) BFRs are not banned or regulated, the chemicals banned under RoHS are being phased out, Al-Hajj says.

Up to 50 million tonnes of waste electronic equipment is being dumped every year, so residual toxic chemicals are one of the fastest-growing environmental problems, says Michael Williams of the UN Environment Programme. Even with many such substances now banned, the problem of dealing with millions of tonnes of older equipment will remain.

Greenpeace wants all toxic chemicals removed from e-goods. Peter Guthrie at the Centre for Sustainable Development in Cambridge, UK, says that for this to happen it will be crucial to ensure that manufacturers have to take back their products at the end of their lives. Only then will they be more inclined to switch to safer new materials.

From issue 2570 of New Scientist magazine, 25 September 2006, page 26-27The greener alternatives

For many of the harmful chemicals traditionally used in electronic equipment, there are now a number of safer alternatives, though as Greenpeace found, they are not used as often as they could be.

POLYVINYL CHLORIDE

PVC, a chlorinated plastic, was once used for insulating wiring. But both production of PVC and its eventual disposal can create persistent and highly toxic dioxins, which pose a major health hazard. Alternatives for PVC vary widely depending upon application, but a variety of non-chlorinated alkene-based plastics, such as polyethylene, can replace it in wiring insulation.

LEAD

Solder used to contain as much as 50 per cent lead, but lead-free solder made up of tin, silver, copper, bismuth and zinc is now widely available. These metals' toxicity and ability to accumulate in the body are far lower than for lead, whose highly toxic effects are the same regardless of whether it is inhaled or ingested. These include irreversible tissue damage, particularly to the developing brain and central nervous system, the kidneys and the reproductive system.

BROMINATED FLAME RETARDANTS

Incorporating BFRs into plastic components is intended to enhance safety by making the material less flammable, but BFRs are now known to be a health risk. They accumulate in biological tissue and have been found in human breast milk, too. Chronic exposure interferes with brain and skeletal development. Animal experiments suggest that this may lead to permanent neurological damage, impairing learning and memory. Other studies have shown that some BFRs can act as endocrine disruptors. The three main classes are polybrominated diphenyl ethers (PBDEs), hexabromo-cyclododecane (HBDC) and brominated bisphenols, in particular tetrabromo-bisphenol-A (TBBPA). Alternatives for BFRs include non-toxic silicone-based flame retardants, for instance, which are recyclable many times over.

HEXAVALENT CHROMIUM

Also known as chromium (vi) or chromate, hexavalent chromium is used in electronics as a corrosion inhibitor. It is highly toxic and a known carcinogen. Replacements include the metal's far less reactive trivalent form or nickel-iron-cobalt alloys.