Section 550.904 - Authorization of hazard pay differential(a) An agency shall pay the hazard pay differential listed in appendix A of this subpart to an employee who is assigned to and performs any duty specified in appendix A of this subpart. However, hazard pay differential may not be paid to an employee when the hazardous duty or physical hardship has been taken into account in the classification of his or her position, without regard to whether the hazardous duty or physical hardship is grade controlling, unless payment of a differential has been approved under paragraph (b) of this section.(b) The head of an agency may approve payment of a hazard pay differential when-(1) The actual circumstances of the specific hazard or physical hardship have changed from that taken into account and described in the position description; and(2) Using the knowledge, skills, and abilities that are described in the position description, the employee cannot control the hazard or physical hardship; thus, the risk is not reduced to a less than significant level.(c) For the purpose of this section, the phrase "has been taken into account in the classification of his or her position" means that the duty constitutes an element considered in establishing the grade of the position-i.e., the knowledge, skills, and abilities required to perform that duty are considered in the classification of the position.(d) The head of the agency shall maintain records on the use of the authority described in paragraph (b) of this section, including the specific hazardous duty or duty involving physical hardship; the authorized position description(s); the number of employees paid the differential; documentation of the conditions described in paragraph (b) of this section; and the annual cost to the agency.(e) So that OPM can evaluate agencies' use of this authority and provide the Congress and others with information regarding its use, each agency shall maintain such other records and submit to OPM such other reports and data as OPM shall require.59 FR 33416, June 29, 1994