I don't see why not. I'd run it through a steriliser and wouldn't give it a second thought. My sister and I borrowed each others when we were visiting each other without thinking. But I'm happy to stand corrected if I've missed something.
I don't know, never having used one, but by instinct I'd say there were 2 issues: hygiene and electrical safety. The former you just have to be sure you can sterilise properly as has already been said. Electrical safety: IMHO we all get too hung up on pointless PAT testing - just check it looks in good condition - no damage or scorch marks etc. Generally these things are subject to stringent design regs which make them safe.
I did and also sold it on afterwards. That's what sterilers are for . what about the pumps you use in hospital and hire from the NCT (bloody marvellous things!). They're not brand spanking new.....well they were once, obviously.
That's an interesting link but I do think the risks are over played somewhat, especially the HIV risk IMHO, because a mother with HIV would be strongly discouraged from breastfeeding her baby anyway because they would pass on the infection to their baby! The fact that there hasn't been any cases of a baby being infected with something nasty from a used breast pump is probably evidence enough for me but I accept that we all have different risk appetites and HCP have a duty of care to make us aware of all risks, however small. It's your decision but if you're worried, bite the bullet and buy brand new. The Medela models are the only ones that worked for me, believe me all breast pumps are not made the same!
But you can buy the attachments new so its only the motor that's secondhand. I had a Medela Mini that I picked up in Tesco for half price and I was delighted with it for bottle a day pumping early on and occasional pumping after.