The U.S. Environmental Protection Agency’s proposed new standard for ground-level ozone, if enacted, would be the most stringent ever proposed. The measure would cost industry billions of dollars to reach compliance, by the agency’s own estimates.
The proposal, signed on Jan. 6, would 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 also proposes a “secondary” standard to protect plants and trees. EPA estimates it will cost between $19 billion and $90 billion to implement the proposal.