Click here for an interactive look at the US Top 50 that lets you sort by company and year, with complete data going back to 2004. DowDuPont tops the list for the second and last time; it is splitting into Dow, DuPont, and Corteva this year. Note: n/a means not available. a Chemical sales less administrative expenses and cost of sales. b Chemical operating profit as a percentage of chemical sales. c Chemical operating profit as a percentage of identifiable chemical assets. d Chemical sales include a significant amount of nonchemical products. e Figures are for the first three quarters of 2018 because of Praxair’s merger with Linde in October. f Fiscal year ended Sept. 30, 2018. g Fiscal year ended Dec. 3, 2018. h Fiscal year ended Nov. 30, 2018.