v3.23.1
Inventories
 3 Months Ended
Mar. 31, 2023
Inventory Disclosure [Abstract]  
Inventories Inventories
($ in millions)March 31, 2023December 31, 2022
Finished products$1,441 $1,209 
Work in process282 238 
Raw materials833 784 
Supplies43 41 
Total Inventories$2,599 $2,272 
Most U.S. inventories are valued using the last-in, first-out method. These inventories represented approximately 16% and 21% of total inventories at March 31, 2023 and December 31, 2022, respectively. If the first-in, first-out ("FIFO") method of inventory valuation had been used, inventories would have been $281 million and $272 million higher as of March 31, 2023 and December 31, 2022, respectively.