Late 1980s and as said most Western European countries (i.e more than 50%) the vast majority were in the EEC.
DIN standards were driven by Germany.
It was possible to get approval to DIN standards, but it was very hard work. Remember these were kettles tested for many years in the UK/ROI.
Strangely kettles were not common in most parts of the EU, because they didn't drink much tea or instant coffee. Consumers would often boil water in pans if they made tea or instant coffee!
I thought so.
The Single Market wasn't created until 1992. What you say was right about the 1980's, which is why the Single Market was created. It solved these issues. I have very little good to say about Margaret Thatcher, but credit where it is due, she was the main architect or driver of this development.
The Single Market meant an agreed set of rules and standards, agreed compliance inspections and an agreed dispute resolution mechanism. What that meant was that anything made within the EU 27 countries could be traded and sold automatically anywhere in the EU without any of that standards nonsense, tariffs and much simplified paperwork. That also extends to goods from any countries the EU has Trade Deals with. Those goods will be subject to checks at the point of entry and sometimes even the factories will be subject to inspection, but once in a shop in the EU a consumer can have trust that the product is of a standard they expect.
Please tell me you knew all that and one of the criteria you used to vote in 2016 was not Kettle DIN standards in the 1980's?