Most likely these devices will be fine, especially if they have worked in Europee, but I would still check. If you look at the transformer (the box attached to the charger cable), it will usually say something like "~110-~240v" - in other words it will accept 110 volts (or anything around 110 - some places use 120, etc which will be fine) and anything up to about 240, and convert that into whatever voltage the device needs to charge.

If the charger doesn't have a transformer, or if the device doesn't have a charger (eg: hairdryer), then these will not work.

-- Mike