Suspect it’ll be either pallet network multidrop or someone like SRCL who collect waste from medical places.
Nothing to worry about although try not to puncture any barrels esp those with corrosive or toxic on them. 
Actually they are amazingly tough as had numerous go over and non bust. Forkies put them through their limits.
Any decent company will have a list of stuff you need depending what you carry a d likely a ticksheet. Ours have quite a lot in a bag and under seat, but medical lot had a bottle of bleech and gloves (yep that was the kit!). Its in their interest to make sure you got the right bits. Also do check fire extinguisher sizes, dates and that they in the green band.
Also remember things like washing powder and fabric conditioner can be ADR.
Do remember to carry the ADR card with you, very important. Plus instructions in writing and paperwork for all ADR contents.
Beyond that, treat it like amy other job.