etiquette for parents leaving kids at party?

[sickoftheholidays]

DS is 6 this year, and while a couple of parents left their kids last year, I am fully expecting this year that most parents will be leaving their kids, but I'm not sure of the protocol in terms of fire safety, and emergency contact numbers.
I left DS for the first time earlier this year, and childs mother seemed a bit surprised when I gave my phone number in case of emergency. Am I just being wierd, or should I ask parents to sign their kids in and leave a contact number in case of emergency? There will be 25 ish kids at the party, and we have me, DH, 2 grandparents and an entertainer, but I'm terrified in case they wander off to the toilet etc etc. Do I need a doorperson to prevent escapees?
Do I sit them down and tell them the "rules" ie no-one leaves the room without telling a grownup where they are going and why? or do I just have someone who will escort kids to the toilets when needed?

I think you'll find that most parents will dump and run and you would struggle to get contact details.
It sounds as though you have booked a venue otherwise the door/ toilet thing wouldn't worry you.
I did lots of these parties when my boys were young and it is a little stressful.
At 6 they really don't need taking to the toilet. I would lock the door once everyone has arrived and just make sure there is an adult in every room the children might use.
I found the trickiest time was when they were not being entertained or organised as they can start to get giddy and rowdy. Unless your entertainer is there for the full duration I would have some games in reserve.
Plus don't be afraid to tell the little darlings to behave if they are being "silly".

My main problem with the toilet is that the venue is quite large, and the toilet is out of the room, through the bar, down the stairs and round the corner - easy for a 6yo to get lost, and to be honest, I dont let my 6yo go to the toilet on their own, they have someone wait outside the cubicle. That may be me being overprotective, but I'd apply my own standards than other kids parents think I'm not taking enough care IYKWIM