What are the deadlines for responding to a request?

Once a FOIA request is received, MSHA has 20 working days in which to make a determination on the request.  In "unusual circumstances," an agency can extend the twenty-day time limit for processing a FOIA request if it tells the requester in writing why it needs the extension and when it will make a determination on the request.  The FOIA defines "unusual circumstances" as (1) the need to search for and collect records from separate offices; (2) the need to search for, collect, and examine a voluminous amount of records "demanded in a single request";  and  (3)  the  need  to  consult  with  another  agency  or  two  or  more  agency components.