FTIR-spectroscopy has been applied for measurements of gas phase rate constants for the reactions of O(1D) with halon 1301 (CBrF3) and halon 2402 (CBrF2CBrF2). Singlet atomic oxygen has been produced by photolysis of ozone at 253.7 nm. Carbonyl fluoride (F2CO) was the dominant product for both reaction systems. CO and CO2 have also been formed. The rate constants have been determined to be 4.16 (±0.39)10-11cm3/molec·sec and 9.15 (±1.22)·10-11cm3/molecsec, respectively. In order to identify possible intermediates these reaction systems have als been investigated in rare gas matrices. Mixtures of CBrF3/16O3/Ar and CBrF3/18O3/Ar were deposited at 12 K and irradiated at various wavelength between 250 and 280 nm. The appearance of two intense bands in the infrared spectra at 1204.3 cm-1 and 1249.2 cm-1 (16O3) or 1193.5 cm-1 and 1250.1 cm-1 (18O3) indicated the formation of CF3OBr.