Hi bottled water is definitely the safer option. All bottles have safety tags attached to the cap, so if you don't feel resistance when you open the bottle, don't drink it! Having bought bottled water all over the world, I have never found a bottle that had been tampered with. Some people may be fine in drinking tap water in various parts of Europe, some may not. It depends on how our bodies react to the bacteria/minerals etc in the water. It would be extremely foolhardy to drink tap water anywhere outside Europe - and I would be very reluctant to use it to wash my teeth either. As I said earlier, better safe than sorry!
All the best,
Bob
Interesting! I would agree with both Jaya and Bob to varying degrees . . .
I have been travelling round Europe since the 1960s (including Romania, Poland, Hungary, Czechoslovakia and Yugoslavia under the old Communist régimes), often, in my hard-up teenager&twentysomething backpacking days, staying in some very dubious "hotels", and never had any problems with drinking the tap water - and nor did any of my travel companions, so it wasn't just me being lucky. The only places I was ever warned about by more experienced travellers were Russia - I was warned never even to brush my teeth using tap water - and Turkey (Istanbul in the 1970s contained the most insect-infested hotel I have ever seen) . . .
So, in most of Europe, I don't think there is a problem for anyone - certainly not in Germany and the Netherlands, which I visit four to six times a year and where I regularly drink the hotel tap water. I would also be confident in Switzerland, Austria, Norway and Sweden - but I am not sure about any of the Latin countries . . .
Outside Europe and the US - no way would I use tap water, even for brushing my teeth. Back in the 1970s, bottled water wasn't a big thing, and we took water purifying tablets when we went to Asian Turkey, dissolved those in the local water, and all survived unscathed. Nowadays, it's always bottled water (with water purifiers as a backup).
As Bob says, it is usually easy to tell whether a bottle has been unsealed and refilled with tap water - and one should always check. In Asia, this has so far never been a problem - but I did attend a high-level international meeting in a western (Latin) European country during a hot summer about ten years ago, where bottled water was provided on the tables for the delegates - and at least one of those bottles had a screw cap which opened without resistance . . . . .
Jim