andres, the principal method of disposal of sharps remains incineration. The definition of sharps nowadays includes the needles, syringes and such things as catheter sets, blades and trocars etc.
Many health authorities now employ specialised contractors to collect sharps bins although GP surgeries still have their bins etc collected by their local hospital from where the contractor collectors them. Incineration on-site at hospitals has proved problematic over the years with HSE regulations becoming stricter since around 1990 and most of those tall chimneys do nothing these days.
Bins containing syringes used with cytotoxic drugs, teratogens and other really nasty stuff have purple lids, but they undergo incineration in the same way.
The contractor call at my university once a fortnight to collect our bins and the service costs quite a few bob annually.