I know two people who represented the UK on EU standardisation committees, one on communications engineering standards and one on medical laboratory practice. They are both professional scientists, not civil servants.
They each sat round a table with fellow scientists from the other European countries to discuss and agree standardisation. These people were not bureaucrats, but experts (if you'll excuse that word) in their field. It is absolutely essential that these scientific standards are agreed, for the sake of safety, research and technological progress. They had minimal administrative support, but the actual decisions were made by the experts.
If we leave the EU we no longer have a place round the table discussing these two areas and so many more where co-operation is essential. We will be powerless to influence the standards but we will still have to abide by them. To do otherwise would be suicidal. Far from "taking back" control we will have relinquished control.
Needless to say these two people, who used to be proud to sit at a table with a little union jack in front of them, are now horrified that our country is to be reduced to this and both voted strongly to Remain.