As of 2015? Have they improved?
The compact fluorescent lamps, whether they are shaped like a coil (eg. ExoTerra 100 - 200 series) or as three bars looped at the top (eg. ZooMed Reptisun and Arcadia Compact Reptile series) are basically just T5-HO fluorescent tubes that have been bent up into a small space, and had a miniature ballast installed in their white plastic base.
So whether they can emit UVC, UVB, UVA and visible light depends, just like all fluorescent tubes, upon the type of glass used, and the phosphor (white powder coating the inside of the glass).
The best quality brands use a borosilicate glass which blocks all UVC and very-short-wavelength UVB, but lets through UVB from 295nm upwards to 320nm, and also all UVA and visible light.
The mercury vapour inside a fluorescent tube, when the lamp is switched on, creates a brilliant arc (like a long thin spark) right down the tube, that emits UVC, UVB, UVA, visible light and a little heat.
The white phosphor coating absorbs the UVC and converts it into more UVB, UVA and visible light.
Any UVC and very-short-wavelength UVB can't get out of the tube into the room, because the glass absorbs it. The glass lets the rest through, so the lamp "emits" UVB from 295nm upwards, UVA, visible light and a little warmth.
Problems usually only occur with very cheaply-made Chinese bulbs and tubes which are made from a quartz glass, and quite possibly, also cheaper phosphor powders. Quartz glass doesn't block short wavelengths - it lets UVC through. (It's what UVC-emitting fluorescent tubes for sterilising water are made out of.) The quartz glass tubes are not always perfectly smooth on the inside; the quartz creates tiny threads like microscopic spikes along the length of the tubes. The phosphor, when it's added (either by dipping or blowing) doesn't stick to these threads. You can see this when you look at a very cheaply-made tube, before it is switched on - you'll see hairlike clear streaks in the white surface. These are tiny gaps where there is no phosphor to catch the UVC. The result is a tube that can "leak" UVC through the tiny clear streaks, when it is switched on. The leaks are very, very small, so the UVC can only be detected at close range. But hey... why risk subjecting your poor reptile to any UVC at all, when better, safer products are available?
Sometimes the phosphor is very thin, too. And sometimes (rarely, nowadays, but I still see one or two sent to me as prototypes) the phosphor they use actually produces very-short-wavelength UVB. These tubes are even worse, and could cause eye and skin problems quite easily if the reptile gets close.