(a) The requirement for the type of position referred to in §550.141 that an employee regularly remain at, or within the confines of, his station must meet all the following conditions:

(1) The requirement must be definite and the employee must be officially ordered to remain at his station. The employee's remaining at his station must not be merely voluntary, desirable, or a result of geographic isolation, or solely because the employee lives on the grounds.

(2) The hours during which the requirement is operative must be included in the employee's tour of duty. This tour of duty must be established on a regularly recurring basis over a substantial period of time, generally at least a few months. The requirement must not be occasional, irregular, or for a brief period.

(3) The requirement must be associated with the regularly assigned duties of the employee's job, either as a continuation of his regular work which includes standby time, or as a requirement to stand by at his post to perform his regularly assigned duties if the necessity arises.

(b) The words “at, or within the confines, of his station”, in §550.141 mean one of the following:

(1) At an employee's regular duty station.

(2) In quarters provided by an agency, which are not the employee's ordinary living quarters, and which are specifically provided for use of personnel required to stand by in readiness to perform actual work when the need arises or when called.

(3) In an employee's living quarters, when designated by the agency as his duty station and when his whereabouts is narrowly limited and his activities are substantially restricted. This condition exists only during periods when an employee is required to remain at his quarters and is required to hold himself in a state of readiness to answer calls for his services. This limitation on an employee's whereabouts and activities is distinguished from the limitation placed on an employee who is subject to call outside his tour of duty but may leave his quarters provided he arranges for someone else to respond to calls or leaves a telephone number by which he can be reached should his services be required.

(c) The words “longer than ordinary periods of duty” in §550.141 mean more than 40 hours a week.

(d) The words “a substantial part of which consists of remaining in a standby status rather than performing work” in §550.141 refer to the entire tour of duty. This requirement is met:

(1) When a substantial part of the entire tour of duty, at least 25 percent, is spent in a standby status which occurs throughout the entire tour;

(2) If certain hours of the tour of duty are regularly devoted to actual work and others are spent in a standby status, that part of the tour of duty devoted to standing by is at least 25 percent of the entire tour of duty; or

(3) When an employee has a basic workweek requiring full-time performance of actual work and is required, in addition, to perform standby duty on certain nights, or to perform standby duty on certain days not included in his basic workweek.

(e) An employee is in a standby status, as referred to in §550.141, only at times when he is not required to perform actual work and is free to eat, sleep, read, listen to the radio, or engage in other similar pursuits. An employee is performing actual work, rather than being in a standby status, when his full attention is devoted to his work, even though the nature of his work does not require constant activity (for example, a guard on duty at his post and a technician continuously observing instruments are engaged in the actual work of their positions). Actual work includes both work performed during regular work periods and work performed when called out during periods ordinarily spent in a standby status.