The EPA doesn’t plan to ask its scientific advisers to review changes to how it justifies the need for major air regulations, which former agency employees and environmental groups say could result in weaker public heath protections.

The Environmental Protection Agency in December is planning to propose revisions to its decades-old practice of how it estimates the costs and benefits of Clean Air Act regulations (RIN:2060-AU51).

But the EPA hasn’t asked its Science Advisory Board, or SAB,...