The board of directors may establish, or [the] commissioner may require any credit union on an individual basis to establish, and transfer funds into one or more special reserve accounts when in the board’s or the commissioner’s judgment such action is necessary to protect the interests of the credit union’s members, including without limitation circumstances when a credit union purchases accounts, or suffers an impairment or threat of impairment that endangers the adequacy of its regular reserve account. Special reserves may include allowances for loan losses and investment losses.