The Environmental Protection Agency is proposing to designate the five-parish Baton Rouge area in compliance with federal ozone pollution standards, possibly easing federal restrictions on proposed new industries.

But the federal ozone standards may change, so the Baton Rouge area may at that point find itself back in non-attainment.

Despite that uncertain future, the EPA announcement Wednesday is a source of pride for state officials.

“This is really a big deal for Louisiana,” said Sam Phillips, assistant secretary of the state Department of Environmental Quality’s office of environmental services. “It will help bring new business to the five-parish area, and we’re all breathing cleaner air because of the work done to get here.”

Actually, the five-parish Baton Rouge area has been meeting the federal ozone standard for several years, and DEQ applied for the redesignation from “severe” to “in compliance” back in 2008, Phillips said.

“Many people felt like this day would never come,” DEQ Secretary Peggy Hatch said of Wednesday’s EPA announcement. “However, with the help from industry, the public, environmental groups and more, we have reached this incredible air quality milestone.”

Air quality data show the metro area — East Baton Rouge, Ascension, Iberville, Livingston and West Baton Rouge parishes — has met the standard since Dec. 31, 2008, according to a DEQ news release.

Since then, air quality data have shown that the five-parish area continues to meet the standard, the EPA release says.

Once the proposed redesignation goes through the comment period and becomes official, it will mean that new industrial construction in the five-parish area will be subject to different regulations.

Under the current regulations for areas with a “severe” designation, proposed new industries must use technology that achieves the lowest achievable emission rate, regardless of cost, said Bryan Johnston, with DEQ’s air permits division.

Under the “attainment” designation, industries can use best available technology, and cost can be factored in; so, if a certain technology is too expensive given how much pollution is reduced, that technology can be ruled out, Johnston explained.

Also, under the current “severe” regulations, if an industry wants to release a certain amount of volatile organic compounds, that industry needs to reduce more than that amount as an offset.

Under the “attainment” rules, industries don’t have to offset those releases, Johnston said.

Phillips added that these rule changes apply only to future projects, and nothing that is currently in place will change.

Ozone is a pollution that forms when nitrogen oxides and hydrocarbons from car exhaust, industrial activities and other sources combine in the air during hot and sunny days. When there isn’t much wind, the ozone pollution can accumulate and cause health problems.

The ozone standard is calculated by taking the fourth highest 8-hour-average ozone reading of the year and averaging three years of that data.

EPA is currently reconsidering what level the 8-hour ozone standard should be, according to the EPA release, and a final decision on the new standard is expected soon.

“Ultimately, what it (Wednesday’s announcement) reflects is there’s been significant progress in the Baton Rouge area,” said Adam Babich, director of the Tulane Environmental Law Clinic. The law clinic has represented environmental groups, including Louisiana Environmental Action Network, in a number of lawsuits aimed at getting ozone levels lowered. One of the consistent issues was efforts to push back deadlines for meeting the standard.

“It’s important to not only celebrate success, but to also plan for the future,” Babich said. With EPA’s expected lowering of the ozone standard coming up, he said, the attainment status won’t last very long. However, the process next time could be easier as the focus will be on lowering ozone levels instead of pushing back deadlines to meet the new standards, he said.