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.