The laser-induced fluorescence technique was used to measure the rate coefficients for the deactivation of DF(v=1) and DF(v=3) in H2, D2, N2, and HF at 200±5 K. The rate coefficients for deactivation by H2, N2, and HF were found to scale with v as v1.9±0.1, essentially the same as the scaling at 295 K. The relaxation rates for DF(v=1) were compared with data obtained at higher temperatures. At 200 K, the exchange probability of HF(1)+H2(0) was the same as that of DF(1)+D2(0) (within 10%) when the endothermicities were considered.