29 C.F.R. § 1620.17

(a) In general. The equal pay standard applies to jobs the performance of which requires equal responsibility. Responsibility is concerned with the degree of accountability required in the performance of the job, with emphasis on the importance of the job obligation. Differences in the degree of responsibility required in the performance of otherwise equal jobs cover a wide variety of situations. The following illustrations in subsection (b), while by no means exhaustive, may suggest the nature or degree of differences in responsibility which will constitute unequal work.

(b) Comparing responsibility requirements of jobs. (1) There are many situations where one employee of a group performing jobs which are equal in other respects is required from time to time to assume supervisory duties for reasons such as the absence of the regular supervisor. Suppose, for instance, that it is the employer's practice to pay a higher wage rate to such a “relief” supervisor with the understanding that during the intervals in which the employee performs supervisory duties the employee is in training for a supervisory position. In such a situation, payment of the higher rate to the employee might well be based solely on the additional responsibility required to perform the job and the equal pay provisions would not require the same rates to be paid to an employee of the opposite sex in the group who does not have an equal responsibility. There would clearly be no question concerning such a wage rate differential if the employer pays the higher rate to both men and women who are called upon from time to time to assume such supervisory responsibilities.

(2) Other differences in responsibilities of employees in generally similar jobs may require similar conclusions. Sales clerks, for example, who are engaged primarily in selling identical or similar merchandise may be given different responsibilities. Suppose that one employee of such a group (who may be either a man or a woman) is authorized and required to determine whether to accept payment for purchases by personal checks of customers. The person having this authority to accept personal checks may have a considerable, additional degree of responsibility which may materially affect the business operations of the employer. In this situation, payment of a higher wage rate to this employee would be permissible.

(3) On the other hand, there are situations where one employee of the group may be given some minor responsibility which the others do not have (e.g., turning out the lights in his or her department at the end of the business day) but which is not of sufficient consequence or importance to justify a finding of unequal responsibility. As another example of a minor difference in responsibility, suppose that office employees of both sexes work in jobs essentially alike but at certain intervals a male and female employee performing otherwise equal work within the meaning of the statute are responsible for the office payroll. One of these employees may be assigned the job of checking time cards and compiling the payroll list. The other, of the opposite sex, may be required to make out paychecks, or divide up cash and put the proper amounts into pay envelopes after drawing a payroll check. In such circumstances, although some of the employees' duties are occasionally dissimilar, the difference in responsibility involved would not appear to be of a kind that is recognized in wage administration as a significant factor in determining wage rates. Under such circumstances, this difference would seem insufficient to justify a wage rate differential between the man's and woman's job if the equal pay provisions otherwise apply.