Bridgestone Firestone North American Tire, a world leader in tire manufacturing, earlier instructed retail stores to stop selling them - safety advocate urges the industry to tighten their standards. Amid growing safety concerns, the company has decided to stop selling used tires at company-owned stores.Bridgestone told its 2,200 retail stores to stop selling used tires. Meanwhile, the Rubber Manufacturers Association for the first time sent a service bulletin warning that "used passenger and light truck tires that have an uncertain or unknown history pose a potential risk."Sean Kane, the president of Safety Research and Strategies, a consumer group, has urged tiremakers to adopt strict standards before selling used tires. "Tire manufacturers have a lot at stake if something goes wrong with a used tire at the end of the day," Kane said. "If their name is on the side of the tire, they have to clean up the mess. I think there is a sea change and selling used tires is yesterday's thing."In December, Kane submitted details about 108 accidents linked to tread separation of tires more than six years old to the National Highway Traffic Safety Administration (NHTSA). Those accidents resulted in 85 deaths. Nationwide statistics are not available.Bridgestone said last Friday that its chief operating officer, Bill Perdew, had told its outlets to stop selling used tires immediately. Perdew told the stores to stop selling used tires in a previously unreported March 29 letter."It was really a small percentage of our business," said Dan MacDonald, a Bridgestone spokesman. "Our strength is to sell new tires, and from a profit standpoint it is a much better market." But MacDonald noted that many independent dealers sell used Bridgestone tires and said that the company was not urging others not to sell used tires. "It may make sense for some tire shops," MacDonald said.MacDonald stressed that when Bridgestone sells used tires, they do a very thorough inspection. "We wouldn't sell anything that wasn't safe," he said. "But taking the time to inspect used tires: Is that a good use of our time?" He added that the prohibition on used tires does not apply to switching summer and winter tires or for tires with less than 500 miles "that are essentially out of the box.”On May 29, the Rubber Manufacturers Association issued a bulletin on used tires. It offered a number of criteria that indicate used tires are unsafe for resale, including the evidence of tread separation, use in "run-flat" mode or a defaced tire identification number. “Any previously recalled tire should not be used, nor tires filled with temporary sealants. Used tires may have been exposed to improper service, maintenance or storage conditions and may have been damaged, which could eventually lead to tire failure," the bulletin said.Other situations that make used tires unsafe include punctures, penetrations, inner liner or bead damage, wear, cuts, cracks, scrapes, bulges, ozone cracking or weather checking, impact damage, punctures, splits, snags, and a history of continuous inflation pressure loss.Wal-Mart, one of the nation's biggest tire sellers, does not sell used tires at its stores, while some other major outlets do. Jim Davis, a Goodyear Tire & Rubber spokesman, said that the company sells a small number of used tires at its 750 company-owned stores. "The bulk of our business is new tires," Davis said, saying used tires are inspected before being sold.Used tires have been the subject of intensifying concern by automakers and safety advocates. In addition, automakers have backed guidelines that tires should only be in service for six years. To promote safety and convenience, it is best to use proven auto parts like the Exedy.