I had been reluctant to comment on this topic. My experience is quite different than the younger chemists.
I have frequently found it difficult to find good data to guide my chemical hygiene. The best rule seems to be keep your exposure to a minimum at all times. However, since a few ideas have been mentioned, I will comment. You should not think of these as anything more than my opinion.
I am generally wary of MSDS data sheets. Since their main purpose seems to be to absolve chemical manufacturers of not warning purchasers of potential hazards, they seem to unnecessarily fearful. I am not disagreeing with them, but I don't value them to determine whether water or dimethylmercury were more toxic, both can kill you.
Okay, how toxic is HF? Will a drop kill you? It is a source of fluoride, is fluoride safe in drinking water? Apparently a reason HF is more dangerous than other acids is because it is a weaker acid and can pass through the skin relatively easily. In the body, HF exerts its toxicity by precipitation of calcium and magnesium ions. (I don't know if that is the same as chronic exposure.)
Methyl iodide has different toxicities associated with it. For the more direct contact, you can find this reported elsewhere. How carcinogenic is it?
http://lmgtfy.com/?q=methyl+iodide+carcinogenicityDisclaimer, I am not advocating safety practices, denial of symptoms, whether to seek medical attention or not, do as I do or did, ignoring MSDS warnings, or anything regarding safety. I simply advocate to judge for yourself. It shouldn't matter if someone else had no adverse reactions if you did, or vice versa.