5 CFR 339.203: Physical requirements.

(a) An agency may establish physical requirements for individual positions without OPM approval when such requirements are considered essential for performance of the duties of a specific position. Physical requirements must be clearly supported by the actual duties of the position, documented in the position description, and supported by a study(ies) or evaluation(s) establishing physical requirement(s) is job-related to the occupation(s).

(b) An applicant or employee may not be disqualified arbitrarily on the basis of physical requirements or other criteria that do not relate specifically to performance of the duties of a specific position.