5 CFR § 2635.802 - Conflicting outside employment and activities.
An employee shall not engage in outside employment or any other outside activity that conflicts with his official duties. An activity conflicts with an employee's official duties:
(a) If it is prohibited by statute or by an agency supplemental regulation; or
(b) If, under the standards set forth in §§ 2635.402 and 2635.502, it would require the employee's disqualification from matters so central or critical to the performance of his official duties that the employee's ability to perform the duties of his position would be materially impaired.
Employees are cautioned that even though an outside activity may not be prohibited under this section, it may violate other principles or standards set forth in this part or require the employee to disqualify himself from participation in certain particular matters under either subpart D or subpart E of this part.