40 to 48 VDC is the usual point at which a device is not considered intrinsically safe for human touching.
Does the power supply have a genuine CE mark? UL mark?Are any parts too hot to touch?Is all conducting metal insulated?
The power supply (12V CD with 5.5mm pin) has a CE mark with IP20 under it and also a TÜV (general testing autority in germany).
It came with the LED stripe so I'd assume it is built for long-time use.
- something in the arduino breaks
(maybe in my soldered circuits or the LED strips)
(the power supply can provide at least 20W which should be enough for electronics to get VERY HOT).