Paypal do a thing called a Moneypool designed for this sort of thing.
Very easy to set up and withdraw the money.
But if you do that, see if you can set the amounts donated to be anonymous because when we started using them for the work collections, the first person who donated to the first one gave an amount that was quite a bit more than what is 'normal' for our organisation (in the days when people used to pass round an envelope, most people gave a couple of quid) and it kind of set a precedent and people felt pressured to keep up and it got a bit out of hand.
But the last one we had you couldn't see the amount, so you could give what you wanted.
Or yes, it is safe to give out your bank account number, as others have said, in the days when cheques were commonplace, these details were on them and no-one worried about giving cheques to strangers.
The only thing you can do with someone else's bank account details is pay money in, or you could try and set up a direct debit, but in the vanishingly small chance that one of your workmates is a fraudster, it's likely it would be detected as antifraud checks, or when they started writing to you about a new DD or you'd be covered by the DD guarantee anyway. You wouldn't lose money.
But it's probably a lot easier to donate by a Paypal moneypool anyway. If you've set up a new payment on your bank account any time recently, you'll know what a pain it is with the anti fraud checks and their repeated questioning about whether or not you know what you're doing or is someone trying to con you.