13 CFR 120.349: Collateral.

Each IT loan must be secured either by a first lien position or first mortgage on the property or equipment financed by the IT loan or on other assets of the Borrower, except that an IT loan may be secured by a second lien position on the property or equipment financed by the IT loan or on other assets of the Borrower, if the SBA determines the second lien position provides adequate assurance of the payment of the IT loan.