Abstract By pumping with a line-narrowed continuously tunable CO 2 laser, we produced about 70 FIR emissions in CH 3F with an efficiency larger than previous works. Some low J and high J transitions were pumped for the first time. The large number of emissions produced in a single laser system allowed us to verify some scaling laws in energy, pressure and FIR tuning. The results agreed with a simple theoretical model also reported. The scaling model also allowed to compare our results with the other ones reported in previous works.