AMD has begun shipping chips with reduced lead content in order to comply with European Union regulations restricting the amount of the metal that may be used in semiconductors.

The EU's RoHS (restriction of hazardous substances) directive restricts the amount of lead that can be used in electronic devices. The directive calls for sales of new electronic products containing lead to be banned in EU-member states after 1 July 2006, but provides for several exceptions, including the use of lead in solder.

AMD began offering RoHS-compliant processors earlier this month, including Opteron, Athlon 64, Athlon 64 X2, Athlon 64 FX, Turion 64 and Sempron processors. The company is also offering RoHS-compliant versions of its server chipsets.

Lead can be harmful to the environment and people, but the metal's unique combination of electrical and mechanical properties makes it ideal for solder, which is used to package semiconductors and bond them to printed circuit boards, including motherboards.

Finding an alternative to lead-based solder hasn't been easy. AMD said it has been working since 2001 on ways to eliminate the use of lead in its chips.

Rival Intel has been hard at work as well. In 2004, Intel began using a lead-free solder to bond chipsets and processors to motherboards. However, the company continues to use a small amount of lead – around 0.2g, according to Intel executives – inside the chip package.

In March, Timothy Mohin, the director of sustainable development at Intel's environment, health and safety department, said the company had spent more than $100m (£57.6m) since 2000 on efforts to eliminate the use of lead in semiconductors. That figure is expected to rise as the company continues its efforts to find an alternative to lead-based solder, he said, noting that Intel hopes its chips will be completely lead-free within five years.

AMD did not disclose how much it has spent to reduce the use of lead in its chips or when it expects to completely eliminate use of the metal in its chips.