BP takes pride in its record of corporate responsibility. But now it has been accused by some of its workers of taking risks with their safety following last week's Alaskan well explosion. They say the oil group has been operating wells suffering from pressure problems, such as the one that exploded, despite failure to perform adequate safety tests because of chronic staff shortages. An internal investigation unveiled that 82 wells in Alaska that had been "yellow tagged" by BP as problematic because of pressure problems were ordered back into operation. In response, BP on Saturday halted production from 150 wells that have recorded high pressures, affecting 60,000 barrels of oil per day, or 6 per cent of its North Slope production in Alaska. BP spokesman, defended the company's operations in Alaska. BP has a comprehensive programme in place for identifying and testing and managing those wells. Those procedures were followed on the A-22 well that exploded. It is understood that investigations by US authorities will look at possible violations by BP of a federal probation order placed on the company after it pleaded guilty in 1999 to the illegal disposal of hazardous waste in Alaska. Probation officers declined to comment. One member of an internal investigating team said it discovered pressure problems dating back to 1998, when it was determined BP needed additional staff to monitor the wells.