3. Inventories

Inventories consist of the following (in thousands):

	March 31, 2018		December 31, 2017
Raw materials	$	772	$	572
Work-in-process		2,519		1,273
Finished goods		600		812
Total inventory	$	3,891	$	2,657

Work-in-process and finished goods as of March 31, 2018 and December 31, 2017 are substantially all conversion costs because the materials used in its production were previously written off.

The Company analyzed its inventory levels to identify inventory that may expire or has a cost basis in excess of its estimated realizable value. The Company performed an assessment of projected sales and evaluated the lower of cost or net realizable value and the potential excess inventory on hand at March 31, 2018. For the three months ended March 31, 2018 the Company recorded a $0.6 million charge to write-off inventory that may expire prior to sale which was recorded as cost of goods sold.