Staples Inc. is expanding its electronics waste recycling program by accepting used computers and monitors that can now be dropped off for a $10 fee at any of the office products chain's 1,400 US locations during store hours. The step by the world's largest office products supplier follows similar initiatives by many computer makers and retailers to confront the growing environmental and public health risk posed by discarded computers and other electronic gadgets containing toxic metals and chemicals. Framingham-based Staples on Monday planned to announce the expansion of a four-year-old program allowing customers to drop off smaller devices such as cell phones, pagers and digital cameras for free, regardless of the brand or whether the device was bought at Staples. Free recycling for those devices will continue at Staples' U.S. and Canadian stores. Starting Monday, desktop and laptop computers and monitors of any make will also be accepted at Staples' customer service desks during store hours, but for a $10 fee for each large item. Staples has offered temporary computer drop-off programs at various locations in recent years - a step other retailers such as rival Office Depot Inc. have also taken. Staples also has offered computer recycling on an ongoing basis in Seattle area stores for the past two years. The expanded program will make Staples the first national retailer to accept computers for recycling on a daily, ongoing basis, said Mark Buckley, Staples' vice president of environmental affairs. Peripherals such as keyboards, mice and speakers will be accepted at no cost. Televisions and floor-model copiers won't be taken. The computer drop-off program isn't being offered in the 21 countries outside the United States where Staples operates. Staples, which stands to boost customer traffic from people turning in old devices, says the $10 fee for large items will defray recycling costs. "When you start to talk about a heavy monitor and a large tower unit for a desktop computer, obviously there is a cost in handling, recycling and shipping," Buckley said. Robin Snider, a spokeswoman for the Computer TakeBack Campaign, a nonprofit advocacy group, urged Staples to consider dropping the $10 fee. "Some people will agree to pay that, but a lot of people will expect to be paid, because their computer may not be old, and computers can become obsolete so quickly now," Snider said. Snider said such drop-off programs "are not a panacea" if recycling isn't done in an environmentally and socially responsible way. Activists say too much of the nation's recycled electronic waste ends up being shipped overseas to poor countries, where it pollutes the environment and can expose workers to dangerous chemicals as they disassemble the devices to salvage precious metals. Staples said its program will ship the devices for domestic recycling by Vestal, N.Y.-based Amandi Services, which Staples calls "one of the country's most experienced and innovative electronics recyclers." Amandi complies with federal standards for electronics recycling and will take steps to ensure personal data stored on old computers aren't compromised, Staples says. "We're not shipping products overseas, and we have a strict chain of custody to make sure we know where these materials are going," Buckley said.