ASHRAE 62.2 does allow local exhaust fans to serve the mechanical exhaust requirement (see Section 4.2). In this case, the system must be designed to meet both the whole-house ventilation and local exhaust requirements. In most cases, this will require controls that do the following: 1) enable fans to run continuously or cycle throughout the day to meet the whole-house ventilation requirement; and 2) enable fans to switch to a higher air flow rate when needed for local exhaust.ASHRAE, Section 5.3.1 also includes a requirement that "readily accessible override control must be provided to the occupant". This may be served through a wall switch or some other mechanism.
Updated 10/1/13 for rating system applicability.