Inventories

Inventories at March 31, 2019 and December 31, 2018 were as follows (in millions):



	March 31, 2019			December 31, 2018
Raw materials and supplies	$	212.5		$	191.5
Work-in-process	941.3			914.1
Finished goods	192.4			191.1
Total inventories at current cost	1,346.2			1,296.7
Adjustment from current cost to LIFO cost basis	4.7			2.9
Inventory valuation reserves	(96.5		)	(88.5		)
Total inventories, net	$	1,254.4		$	1,211.1

Inventories are stated at the lower of cost (last-in, first-out (LIFO), first-in, first-out (FIFO), and average cost methods) or market. Most of the Company’s inventory is valued utilizing the LIFO costing methodology. Inventory of the Company’s non-U.S. operations is valued using average cost or FIFO methods. Due to deflationary impacts primarily related to raw materials, the carrying value of the Company’s inventory as valued on LIFO exceeds current replacement cost, and based on a lower of cost or market value analysis, the Company maintains NRV inventory valuation reserves to adjust carrying value of LIFO inventory to current replacement cost. These NRV reserves were $9.9 million at March 31, 2019 and $8.0 million at December 31, 2018. Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV inventory reserves were as follows (in millions):



	Three months ended March 31,
	2019			2018
LIFO benefit (charge)	$	1.8		$	(8.2	)
NRV benefit (charge)	(1.9		)	8.2
Net cost of sales impact	$	(0.1	)	$	—