you're right. in contrast to my examples wikipedia's trans fat article says, >Because of these facts and concerns, the NAS has concluded there is no safe leve

you're right. in contrast to my examples wikipedia's trans fat article says, >Because of these facts and concerns, the NAS has concluded there is no safe level of trans fat consumption. There is no adequate level, recommended daily amount or tolerable upper limit for trans fats. This is because any incremental increase in trans fat intake increases the risk of coronary heart disease. maybe a better example than the ones I listed (for which as you point out there are safe levels of consumption), would be smoking tobacco, which I think matches the above description and has no safe level. But it is not banned outright. (at least not yet.)