Exhibit 99.1 INNOSPEC REPORTS FIRST QUARTER 2024 FINANCIAL RESULTS Strong contribution from Performance Chemicals drives operating income growth of 23 percent $80.6 million cash generated from operations; Net cash improves to $270.1 million Dividend increased by 10 percent; Strong debt-free balance sheet GAAP EPS of $1.65 and adjusted non-GAAP EPS of $1.75 Englewood, CO – May 9, 2024 – Innospec Inc. (NASDAQ: IOSP) today announced its financial results for the first quarter ended March 31, 2024. The Company ...