Debt



	March 31, 2018		December 31, 2017
Debt classified as current liabilities:
Hancock County industrial revenue bonds ("IRBs") due April 1, 2028, interest payable quarterly (variable interest rates (not to exceed 12%)) ⁽¹⁾	$	7.8	$	7.8
Debt classified as non-current liabilities:
7.5% senior secured notes due June 1, 2021, net of debt discount of $1.7 million and $1.8 million, respectively, interest payable semiannually	248.3		248.2
Total	$	256.1	$	256.0

⁽¹⁾ The IRBs are classified as current liabilities because they are remarketed weekly and could be required to be repaid upon demand if there is a failed remarketing. The IRB interest rate at March 31, 2018 was 1.78%.

7.5% Notes due 2021

General. On June 4, 2013, we issued $250.0 million of our 7.5% Notes due June 1, 2021 (the "2021 Notes") in a private offering exempt from the registration requirements of the Securities Act of 1933, as amended. The 2021 Notes were issued at a discount and bear interest at the rate of 7.5% per annum on the principal amount, payable semi-annually in arrears in cash on June 1st and December 1st of each year.

Fair Value. Fair value for our 2021 Notes was based on the latest trading data available and was $255.3 million and $258.3 million, as of March 31, 2018 and December 31, 2017, respectively. Although we use quoted market prices for identical debt instruments, the markets on which they trade are not considered to be active and are therefore considered Level 2 fair value measurements.

U.S. Revolving Credit Facility

We and certain of our direct and indirect domestic subsidiaries are party to a senior secured revolving credit facility, dated May 24, 2013, as amended, with a syndicate of lenders which provides for borrowings of up to $150.0 million in the aggregate, including up to $110.0 million under a letter of credit sub-facility (the "U.S. revolving credit facility"). Our U.S. revolving credit facility matures in June 26, 2020. Any letters of credit issued and outstanding under the U.S. revolving credit facility reduce our borrowing availability on a dollar-for-dollar basis. The availability of funds under the U.S. revolving credit facility is limited by a specified borrowing base consisting of accounts receivable, inventory and qualified cash deposits of the borrowers which meet the eligibility criteria.



Status of our U.S. revolving credit facility:	March 31, 2018
Credit facility maximum amount	$	150.0
Borrowing availability	150.0
Outstanding letters of credit issued	39.1
Outstanding borrowings	—
Borrowing availability, net of outstanding letters of credit and borrowings	110.9

Iceland Revolving Credit Facility

We have also entered into, through our wholly-owned subsidiary Nordural Grundartangi ehf, a $50.0 million revolving credit facility, dated November 27, 2013, as amended (the "Iceland revolving credit facility"). The Iceland revolving credit facility expires on November 27, 2020. The availability of funds under the Iceland revolving credit facility is limited by a specified borrowing base consisting of inventory and accounts receivable of Grundartangi.



Status of our Iceland revolving credit facility:	March 31, 2018
Credit facility maximum amount	$	50.0
Borrowing availability	50.0
Outstanding borrowings	—
Borrowing availability, net of borrowings	50.0