BASIS OF PRESENTATION We prepared these consolidated financial statements in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information, the instructions to Form 10-Q and Article 10 of U.S. Securities and Exchange Commission (SEC) Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, these consolidated financial statements reflect all adjustments that are of a normal recurring nature necessary for a fair presentation of our results of operations, financial condition, and cash flows for the interim periods presented. The preparation of these consolidated financial statements requires us to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base these estimates on historical experience and on various other assumptions that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying amounts of assets and liabilities that are not readily apparent from other sources. Our actual results may differ materially from these estimates. Significant estimates inherent in the preparation of our consolidated financial statements include, but are not limited to, accounting for sales and cost recognition, postretirement benefit plans, environmental receivables and liabilities, evaluation of goodwill and other assets for impairment, income taxes including deferred tax assets, fair value measurements and contingencies. The consolidated financial statements include the accounts of subsidiaries we control and variable interest entities if we are the primary beneficiary. We eliminate intercompany balances and transactions in consolidation. We close our books and records on the last Sunday of the calendar quarter, which was on June 30 for the second quarter of 2019 and June 24 for the second quarter of 2018 , to align our financial closing with our business processes. The consolidated financial statements and tables of financial information included herein are labeled based on that convention. This practice only affects interim periods as our fiscal year ends on December 31. We adopted Accounting Standards Update (ASU) 2016-02, Leases (Topic 842), effective January 1, 2019, using the optional transition method whereby we applied the new lease requirements under ASU 2016-02 through a cumulative-effect adjustment, which after completing our implementation analysis, resulted in no adjustment to our January 1, 2019 beginning retained earnings balance. Consequently, periods prior to January 1, 2019 are not restated for the adoption of ASU 2016-02. See  Note 6  Leases  and  Note 12  Recent Accounting Pronouncements  for more information regarding our adoption of this standard. Other than the changes in our accounting policies related to adoption of ASU 2016-02, we followed the accounting policies disclosed in the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018 ( 2018 Form 10-K) filed with the SEC. The results of operations for the interim periods presented are not necessarily indicative of results to be expected for the full year or future periods. Unless otherwise noted, we present all per share amounts cited in these consolidated financial statements on a per diluted share basis. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our 2018 Form 10-K.