For me it would largely depend on the size/calibre/power of what cat3 you are lighting, and whether you are going to be close to it (or not). To get dressed up in fire retardant overalls hardhat eardefenders eye protection and gloves for lighting a lot of small Cat 3 25 metre selection box material ie ESCO/Sovereign selection boxes and small Cat 3 25 metre pack material is a little pointless, a lot of faff and overkill, but I find that a minimum of hardhat and goggles/safety glasses IS an advisable and sensible precaution in case of anything untoward happening;as Tony Sales says, "I think it's fair enough to wear some PPE doing a display because you cannot be sure what is going to go smoothly and even a small burning ember from a rocket from the sky and landing in your eyes or on your head can cause an injury." However if you are going to be firing a lot of separate Cat 3 such as; Larger barragepack material, Large Cat 3 cakes, candles and barrages, Large Cat 3 rocket selection packs, Large single Cat 3 rockets, Mixed 1.3g Cat 3 multiple rocket packs with various sizes (not the tame rubbish weak 1.4g Cat 3 multiple rocket packs with pathetic weak bursts), Cat 3 mines(mortar and fountain start), Large Cat 3 fountains, Large Cat 3 wheels and other large separate Cat 3 fireworks, (and you're going to be at close range lighting multiple fuses/fireworks with rothy/portfires running through sparks/crackling comets etc to light stuff) then going all out with full ppe for this ie hard hat/eye protection/eardefenders/gloves/fire retardant overalls/sensible footwear etc in this instance is a sensible idea; firstly it protects your clothes from being burned/melted/ruined, and secondly if anything untoward happens, then you will be fully protected (come what may) in the event of any accident. Over to you what do you think? However if all you intend to do is just light one Cat 3 25m firework at a time from a mixed Cat 3 25m selection pack/selection box and retire to a safe distance:then going all out in PPE in that instance for one item at a time is totally unnecessary because you aren't gonna be close up to it while it goes off.