Inventories

We value our raw materials, work in process, and finished goods inventories using lower of cost, as determined by the average cost method, or market. Supplies and materials are valued at the first-in, first-out (FIFO) or average cost methods.

The components of inventories were as follows (dollars in millions):



	March 31, 2016		December 31, 2015
Raw materials	$	272.0	$	260.6
Work in process	12.0		14.2
Finished goods	190.6		189.7
Supplies and materials	217.9		212.3
Inventories	$	692.5	$	676.8