An Electronics Weekly/Farnell InOne roundtable to debate the problems of RoHS and WEEE compliance discussed the contaminants in components, how to test for them and the best way to get rid of them

Where can you find contamination and how do you tell if a component going into a product is compliant?

This was a major topic of conversation when a group of industry experts was pulled together by Farnell InOne and Electronics Weekly to exchange ideas and interpretations of the RoHS and WEEE Directives.

Aside from the actual components and PCBs, plastics and metalwork can be a minefield. “There is cadmium and mercury in steels,” says Mark Shayler of environmental consultancy Eco3. “We are finding more and more.”

According to Shayler, 60 per cent of steel is recycled. Mercury added to soften a steel product years ago, or cadmium added for wear resistance, could be in the steel parts you are incorporating. “We are still finding many cases above the [RoHS] threshold,” he says.

Testing for these contaminants is hard without resorting to time-consuming wet chemistry, but it is possible. There are two main options: electron microscope-based EDX and X-ray-based XRF. “XRF is much more reliable,” says Shayler. “There is room for operator misinterpretation with EDX.”

Whereas mercury and cadmium are banned completely, bromine and chromium give subtler problems as hexavalent chromium and two families of brominated fire-retardants are banned, leaving trivalent chromium and numerous bromine compounds perfectly legal. “You will see if you have got chromium or bromine, but you need several rounds of tests to see if it is banned chromium or bromine,” says Shayler.

Donal Horgan, a materials specialist at Molex, agrees. “To my knowledge, it is down to pretty fine instrumentation to do it,” he says.

Horgan has been looking into brominated fire-retardants which are found in high-temperature plastics. “Brominated compounds are quite a challenge,” he says. “You need to do a mass spectrum on it and at the end of the day, it is down to a highly specialised person to interpret it.”

Difficulties in identifying bromine compounds and safety concerns about several more bromine-based fire retardants - some of the more toxic ones have been banned for years - mean bromine is under the spotlight.

“There is a lot of debate in industry. There are a lot of challenges and a lot of the main players are focused on this,” says Horgan.

Sweden, for example, has side-stepped determining which bromine compound is which by banning the lot. If you are exporting to Sweden, do not use any brominated fire-retardants.

Plastics makers may not even add banned compounds, but Horgan warns they can be produced inside plastic components by chemical reactions between legal compounds during manufacture - which is why some big players are looking to remove all bromine from their plastics.

And bromine is not the only issue with plastics. Cadmium was used in plastics and: “Every piece of PVC that was manufactured more than five years ago had lead in it,” says Horgan. “It was pretty much right across the market.”

His advice is choose your plastics supplier with care. “Sourcing from the Far East is pretty risky,” he says.

It emerges that lead can accidentally find its way into purportedly lead-free components. “We were analysing a gold-plated connector and we found lead,” says Leigh Holloway, of Eco3. It did not show up under EDAX, indicating the lead was not in the gold plating but under it. “The only way to find the lead was to dissolve the component leg,” says Holloway.

Molex’s Horgan - which did not make the connector in question - says: “Nickel sulphomate is almost an industry standard for plating, and there is no lead in it at all,” he says. “And lead at more than 5ppm is a poison in gold.” Horgan’s best guess was that the lead was in or on the brass core of the contacts.

Running lead-inclusive and lead-free materials through the same machinery can result in cross-contamination, says Molex’s Matt Wilhite. “The best way to [make lead-free components] is to get lead out of the factory completely.”

Distributor Farnell InOne has been testing for banned substances in supposedly compliant components. “Random testing has shown up quite a few,” says head of RoHS and WEEE Gary Nevison. To get control of the mavericks, the firm has now expanded its testing programme.

Nevison also warns component buyers not to get hoodwinked by marketing - a lead-free logo does not always mean RoHS compliance.

Complying with the WEEE Directive was another hot topic at the roundtable.

Whereas the RoHS Directive bans substances from all consumer electrical and electronics equipment, the WEEE Directive in its Annex 2 describes what needs to be removed or treated in consumer waste before it is recycled.

Businesses have to recycle, and consumers are encouraged to recycle by the compulsory crossed-out wheelie bin logo on products covered by the Directive.

Alan Duckinfield is a recycling expert from recycler RID, and contributes to the Government’s Envirowise scheme. He sees ways in which manufacturers can simplify the recycling process. “People should speak to a recycler before they decide how a product should come apart,” he says.

To help with the flow of recycling information, the European Recycling Association has produced a one page template that producers can use to notify recyclers of the location of any hazardous components in a product.

To comply with the WEEE Directive, ‘producers’ either have to recycle their own products, or join a compliance scheme which, at a price, will take on a producer’s WEEE Directive responsibility. “The schemes will register, do all the waste management and produce all the documentation,” says Duckinfield.

Farnell’s Nevison, who also heads RoHS and WEEE at distribution industry body Afdec, says: “For companies that only have a small amount of WEEE, it might be better to go with an independent recycler and pay as they go,” he says. “Larger suppliers will go with a compliance scheme.”

WEEE cost can be summed up as those for recovery, recycling and reporting.

Producers, or their compliance schemes, are responsible for much of this, but are looking for ways to pass on the expense.

Eco3’s Shayler has a warning for any organisation on the other side of the fence, that is buying equipment - read sales contracts thoroughly.

If they fail to study before they sign “end-users could cop the whole lot”, he says.

For more content relating to the WEEE Directive, please visit our guide to the WEEE Directive and UK WEEE regulations