Inventories

The major components of inventories were as follows:



	September 30, 2018		December 31, 2017
Petroleum products	$	21,082	$	8,731
Crude oil	16,493		29,873
Caustic soda	8,030		5,755
NaHS	9,682		8,277
Raw materials - Alkali operations	5,592		4,550
Work-in-process - Alkali operations	2,820		7,355
Finished goods, net - Alkali operations	11,526		14,075
Materials and supplies, net - Alkali operations	10,496		10,030
Other	1		7
Total	$	85,722	$	88,653

Inventories are valued at the lower of cost or net realizable value. The net realizable value of inventories were below recorded costs by approximately $0.1 million as of September 30, 2018 without similar adjustments required as of December 31, 2017.