Code of Federal Regulations Title 5. Administrative Personnel § 5.550.906 Termination of hazard pay differential

(a) One or more of the conditions requisite for such payment ceases to exist;

(b) Safety precautions have reduced the element of hazard to a less than significant level of risk, consistent with generally accepted standards that may be applicable, such as those published by the Occupational Safety and Health Administration, Department of Labor;  or

(c) Protective or mechanical devices have adequately alleviated physical discomfort or distress.