It is probably the most corrosive thing you are likely to encounter outside of an industrial process site. There are far, far, worse reagents out there, but they are rare. In fact, some chemists have even blogged about stuff they would chose not to work with:
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc