Leaking batteries

[worriedatthemoment]

Just got the decorations out of loft
Dh had put away unbeknown to me some batterie operated decoration thing and whilst in storage the batteries have obviously leaked.
Only found this item at bottom after putting up most of decs
Not the white powder though the batteries were wet/ greasy its how i noticed as i picked up by the batter compartment and was greasy and wet. I washed my hands and put item in a bag tied up with batteries.
The remaining things in bag all looked ok apart from one thing had a little mark on so i washed them with soap and water just incase.
Should i just dispose of these things though ? Not sure if on anything else we got out but nothing appears to be sticky or have powder on
I have had leaked batteries before with white powder but never wet stick substance is this battery acid ?

To add batteries have prob been in loft few years as it was in a bag of forgotten things that i hadn't been able to find , so not surprised they leaked in all honesty

The cold and heat will have contracted and expanded them to cause the leak. Dispose of the item they were in and I'd say the rest will be fine. Note for future, remove batteries before storage!

I had removed all the other batteries just this one item which must of been overlooked. Just never come across liquid leaking from them normally just powder residue.