The Environmental Protection Agency’s recently released cost-benefit analysis for its proposed ozone standard is being criticized on two fronts.

Industry groups claim that EPA’s analysis understates the proposal’s costs and also say its health benefits are difficult to quantify. On the other hand, OMB Watch, an advocacy organization, contends that EPA’s analysis underestimates the health benefits of a more stringent standard.

EPA in June proposed tightening the standard from the current 0.084 parts per million to between 0.070 ppm to 0.075 ppm. The agency also left open the options of keeping the current standard or toughening it to 0.065 ppm. EPA will hold public hearings Aug. 30 and Sept. 5 on the proposal.