45 CFR §2105.17

1. (a)The Agency may extend the basic time limit, if unusual circumstances exist, by notifying you in writing of:
   1. (1)The unusual circumstances involved; and
   2. (2)The date by which it expects to complete processing the request.
2. (b)If the processing time will extend beyond a total of 30 workdays, the Agency will:
   1. (1)Give you an opportunity to limit the scope of the request or agree to an alternative time period for processing; and
   2. (2)Make available its FOIA Public Liaison (see § 2105.63) to assist in resolving any disputes between you and the Agency, and notify you of your right to seek dispute resolution from the Office of Government Information Services (OGIS).
3. (c)If the Agency extends the time limit under this section and you do not receive a response in accordance with § 2105.15(a) in that time period, you may consider the request denied and file an appeal in accordance with the procedures in § 2105.56.
4. (d)Your refusal to reasonably modify the scope of a request or arrange an alternative time frame for processing a request after being given the opportunity to do so may be considered for litigation purposes as a factor when determining whether exceptional circumstances exist.