Rate constants for the OH and Cl reactions with four aromatic aldehydes have been determined at 298 ± 2 K and atmospheric pressure using a relative rate method. The measured rate constants are (in cm³ molecule⁻¹ s⁻¹):

k_OHk_ClBenzaldehyde(1.2 ± 0.2) × 10⁻¹¹(10 ± 1) × 10⁻¹¹o-Tolualdehyde(1.8 ± 0.2) × 10⁻¹¹(19 ± 2) × 10⁻¹¹m-Tolualdehyde(1.7 ± 0.2) × 10⁻¹¹(17 ± 2) × 10⁻¹¹p-Tolualdehyde(1.3 ± 0.2) × 10⁻¹¹(14 ± 2) × 10⁻¹¹This work provides the first measurements for the OH and Cl reaction rate constants with tolualdehydes. The results obtained are presented and compared with the previous measurements only available for benzaldehyde. The atmospheric implications are also discussed.