" Until then, nothing breaching the standards should be admitted."
Anything breaching the standards is liable to confiscation and the consumer has additional protection offered by the consumer rights bill, should goods not be of the requisite standard. Over time the web of protection offered to consumers and workers covering every aspect of their lives has become ever more protective.
Do you anticipate these protections being rolled back as a result of brexit.?

much of this legislation originated in the UK long before the EU was even a gleam in someone's eye:

The factory act of 1802
The factories act 1833 and HM factory Inspectorate

etc, etc,
and more recently the Cullen report on Piper Alpha 1990 that impacted oil and gas exploration worldwide.
The UK was a world leader in protective legislation both before and after membership of the EU.
Why would brexit change this? The very idea is risible!