The U.S. Environmental Protection Agency on Jan. 7 proposed tougher standards for ground-level ozone, saying that the stricter requirements will protect public safety and health. The new standards, if enacted, would replace the standards set by the previous administration and would be the strictest ever proposed.

EPA says it is proposing to set the “primary” standard, which protects public health, at a level of between 0.060 parts per million and 0.070 ppm measured over eight hours. EPA is also proposing that a separate “secondary” standard be set within the range of 7-15 ppm to protect plants and trees.

In 2008, The Bush administration revised the standards for the first time in more than a decade, to 0.075 ppm, for both the primary and secondary standard. But the Bush administration regulation was widely criticized by both environmental groups, who said the standard was not strong enough, and industry groups, who said that a new standard was unnecessary.

EPA says it made the decision to propose a stricter standard based on a review of more than 1,700 scientific studies and public comments from the 2008 rulemaking process as well as findings from the independent Clean Air Scientific Advisory Committee, which recommended that the standard be set no higher than 0.070 ppm.

Construction and industry groups such as the American Road and Transportation Builders Association have said that tougher standards would push more counties into non-attainment, potentially delaying federal dollars for transportation projects.

But environmental and health advocates have been quick to praise the EPA’s announcement. Bill Becker, the National Association of Clean Air Agencies’ executive director, says, “State and local air quality officials are fully aware of the daunting challenges implementation of such new standards will pose.” But he adds, “Though the task of putting new, better standards into practice won’t be easy, it will most certainly be worth it.”

EPA says it will take public comment for 60 days after the proposed rule is published in the Federal Register.