40 C.F.R. § 2.403
A request for testimony by an EPA employee under § 2.402(b) must be in writing and must state the nature of the requested testimony and the reasons why the testimony would be in the interests of EPA. Such requests are immediately sent to the General Counsel or his designee (or, in the case of employees in the Office of Inspector General, the Inspector General or his designee) with the recommendations of the employee's supervisors. The General Counsel or his designee, in consultation with the appropriate Assistant Administrator, Regional Administrator, or Staff Office Director (or, in the case of employees in the Office of Inspector General, the Inspector General or his designee), determines whether compliance with the request would clearly be in the interests of EPA and responds as soon as practicable.
40 C.F.R. §2.403