Originally on Broadsheet where the test was to be conducted with a 13 litre flush
10 sheets to be used for three flushes and one sheet remaining from the total of thirty sheets flushed constituted a failure.
When tabloids came in flush volumes had fallen to ll litres and the failure level moved to a pass if one sheet was left out of the thirty flushed
By the time 9 litres became the standard the test was dropped, you were lucky if you could get half the sheets to flush.
So then a version of the test using first Izal medicated toilet paper set the ball rolling again.
And lo it came to pass the flush volume went down to six litres and soft toilet tissue was used in the tests and of course they are much smaller and easier to flush
Then down went the flush volume to 4.5 litres
I think you can guess what happened!
Flush valves thankfully became legal
And in any case Building sites became deluxe places that didn't use Newspaper in the same way!
During the years of reducing flush volumes we had to do a a lot o research on what appears at first glance a very simple water displacement in the pan, and removal of solids, which it most assuredly is not.
However after Brexit there will be a new productivity incentive and the introduction of this revolutionary product
Guaranteed to give a flush to the cheeks!