A Silicon Valley environmental group is praising Hewlett-Packard Co. for its computer recycling efforts in Roseville but blasting Dell Inc. for using prison labor for a similar program.

In a report released Thursday, the Silicon Valley Toxics Coalition highlighted HP's partnership with recycler Micro Metallics in Roseville as a model of worker safety and efficiency. HP contracts with Micro Metallics for both its internal recycling and to recycle electronics from the public.

By contrast, the toxics coalition criticized Dell for contracting with Unicor, a division of the federal Bureau of Prisons, to recycle computers at the Atwater federal penitentiary in the San Joaquin Valley.

The report said the prisoners work under potentially dangerous conditions that involve such tasks as breaking up lead-laden computer monitors with hammers. "Unicor's primitive practice of manually smashing leaded glass in cathode ray tubes unnecessarily exposed workers to risk of toxic contamination and cuts," the report stated.

Ted Smith, toxics coalition executive director, said: "As long as we have a low-cost, low-end option available, we won't build a commercially viable infrastructure for dealing with e-waste in the United States."

But representatives of Dell and Unicor disputed those conclusions, saying prisoners work in safe conditions and that there's a waiting list of applicants for the recycling jobs.

A state inspector this month also said the prisoners were dismantling computer monitors in an environmentally acceptable manner.

"We take great pride in the safety of our workers," said Lawrence Novicky, general manager of Unicor's recycling business group. "We meet all OSHA requirements and all federal, state and local environmental regulations."

The report comes amid nationwide efforts to grapple with the mounting problem of electronic waste. According to the National Safety Council, Americans dump more than 3.2 million tons of electronic gear into U.S. landfills every year. Televisions and computer monitors contain up to 4 pounds of lead, as well as other toxic substances that can leach into the water table.

HP, Dell and other manufacturers have established recycling programs for personal computers and other electronics gear. But the program aren't cost-free to consumers: While HP charges about $46 to recycle a computer and monitor, Dell charges $15. Both prices include shipping.

In its report, the toxics coalition commended the HP-Micro Metallics operation on the outskirts of Roseville. Workers there employ the latest high-tech recycling equipment and receive training in handling hazardous materials.

In the prison recycling program, by contrast, workers use crude equipment such as hammers to dismantle computers. The report acknowledged, however, that prisoners who break up monitors wear full protective suits and respirators. Furthermore, the areas where computer monitors are destroyed are equipped with air filtration systems.

The report criticized Unicor for not allowing inmates to speak with toxics coalition representatives. Novicky responded that conversations were allowed under standard federal prison guidelines.

A visit to the prison this month by an inspector for the state Department of Toxic Substance Control showed that the prisoners were dismantling monitors in an "environmentally acceptable manner," said Kim Wilhelm, head of the department's statewide compliance division.

The inspector did not evaluate air quality or worker health and safety issues, Wilhelm said.

Dell spokesman Bryant Hilton said his company is satisfied with Unicor and has no intention of changing its recycling program. "We think the report is biased," Hilton said. "We selected Unicor just as we would any vendor. They all have to meet the same safety and environmental standards."

The state of California recycled 370 tons of electronics gear through Unicor last year and has no complaints about the service, said Robb Deignan, a spokesman for the state Department of General Services.

Kate Krebs, executive director of the nonprofit National Recycling Coalition, said the toxics coalition is taking too narrow a view of recycling e-waste. "To say that HP is good and Unicor is bad is not something we would agree with," she said. "Companies like Dell and HP and Panasonic are trying to step up to the plate on this issue. Dell is getting beat up on a report that is kind of slim on facts."

The toxics coalition, known for crusading for workers rights, was one of the first organizations to highlight risks to low-income workers and the environment in Silicon Valley's chip manufacturing industry. Last year it issued a scathing report on the practice of sending e-waste to Asia, where it was recycled under virtually no environmental rules.

Unlike low-wage factory workers or child workers in Asia, federal prisoners might have trouble generating much sympathy, Smith acknowledged. "This is an important environmental justice issue," he said. "These are often poor people of color who don't have any options. ... They are being put at risk."