> This is an open-front toilet seat, and thanks to the American Standard National Plumbing Code, it’s the go-to for most public restrooms. This code was created in 1955 and further cemented by the Uniform Plumbing Code in 1973 by the International Association of Plumbing and Mechanical Officials (IAPMO).
You can follow the links in the article I linked, or do a bit more Googling.
> This is an open-front toilet seat, and thanks to the American Standard National Plumbing Code, it’s the go-to for most public restrooms. This code was created in 1955 and further cemented by the Uniform Plumbing Code in 1973 by the International Association of Plumbing and Mechanical Officials (IAPMO).
You can follow the links in the article I linked, or do a bit more Googling.
It's not a single uniform law, but a code that then got (and gets) adopted by lots of localities using different legal mechanisms. See https://en.wikipedia.org/wiki/Uniform_Plumbing_Code