5 C.F.R. § 550.153

(a) The requirement in § 550.151 that a position be one in which the hours of duty cannot be controlled administratively is inherent in the nature of such a position. A typical example of a position which meets this requirement is that of an investigator of criminal activities whose hours of duty are governed by what criminals do and when they do it. He is often required to perform such duties as shadowing suspects, working incognito among those under suspicion, searching for evidence, meeting informers, making arrests, and interviewing persons having knowledge of criminal or alleged criminal activities. His hours on duty and place of work depend on the behavior of the criminals or suspected criminals and cannot be controlled administratively. In such a situation, the hours of duty cannot be controlled by such administrative devices as hiring additional personnel; rescheduling the hours of duty (which can be done when, for example, a type of work occurs primarily at certain times of the day); or granting compensatory time off duty to offset overtime hours required.

(b) In order to satisfactorily discharge the duties of a position referred to in § 550.151, an employee is required to perform substantial amounts of irregular or occasional overtime work. In regard to this requirement:

(1) A substantial amount of irregular or occasional overtime work means an average of at least 3 hours a week of that overtime work.

(2) The irregular or occasional overtime work is a continual requirement, generally averaging more than once a week.

(3) There must be a definite basis for anticipating that the irregular or occasional overtime work will continue over an appropriate period with a duration and frequency sufficient to meet the minimum requirements under paragraphs (b)(1) and (2) of this section.

(c) The words in § 550.151 that an employee is generally “responsible for recognizing, without supervision, circumstances which require him to remain on duty” mean that:

(1) The responsibility for an employee remaining on duty when required by circumstances must be a definite, official, and special requirement of his position.

(2) The employee must remain on duty not merely because it is desirable, but because of compelling reasons inherently related to continuance of his duties, and of such a nature that failure to carry on would constitute negligence.

(3) The requirement that the employee is responsible for recognizing circumstances does not include such clear-cut instances as, for example, when an employee must continue working because a relief fails to report as scheduled.

(d) The words “circumstances which require him to remain on duty” as used in § 550.151 mean that:

(1) The employee is required to continue on duty in continuation of a full daily tour of duty or that after the end of his regular workday, the employee resumes duty in accordance with a prearranged plan or an awaited event. Performance of only call-back overtime work referred to in § 550.112(h) does not meet this requirement.

(2) The employee has no choice as to when or where he may perform the work when he remains on duty in continuation of a full daily tour of duty. This differs from a situation in which an employee has the option of taking work home or doing it at the office; or doing it in continuation of his regular hours of duty or later in the evening. It also differs from a situation in which an employee has such latitude in his working hours, as when in a travel status, that he may decide to begin work later in the morning and continue working later at night to better accomplish a given objective.