The Environmental Protection Agencyhas unveiled a new version of a rule that would regulate air pollution from industrial boilers, which burn a wide range of fuels. The more flexible rule has angered environmental groups, while industry is cautiously optimistic.The boiler rule was one of the many Clean Air Act revisions the EPA has been releasing this year. The rule was finalized in March, but since then the agency has been gathering more input.EPA Air Administrator Gina McCarthy describes the revised rule as one that hits the so-called ‘sweet spot’—the maximum bang for minimal bucks.“The data we received show that EPA could set standards that would be a bit more flexible while we maintained the significant health benefits that we saw in the March final.”Earthjustice, an environmental non-profit, reacted with disappointment to what it calls a weakening of the standard, but expressed hopes that the rule change would cause Congress to drop their opposition to the boiler rule.Robert Bessette is the president of the Council of Industrial Boiler Owners. He says from the industry's perspective, this version is a big improvement over the previous one."They've expanded some of the stuff," he said. Some of the stuff, it looks like they've improved it. Some of the numbers have become more stringent."Bessette said changes the EPA had made in the regulation of dioxides, in particular, is good, and he's pleased with the time the EPA had spent on the rule.The public has 60 days to submit comments on the revision.