I found this on The Toilet Museum Web site
The open front toilet seats afford the users more sanitary conditions and a greater sense of comfort than their residential closed-front cousins. The reason that the open front toilet seats are so widely used in the U.S. is due to section 409.2.2 of the Uniform Plumbing Code. The Uniform Plumbing Code is written and maintained by the International Association of Plumbing and Mechanical Officials. The code has been adapted into law, in whole or part, by most of the United States.
I found some funny thoughts on this also:
And very graphic and down-to-earth answers here:
- More sanitary because of the men peeing and women using TP? It seems so... ;-)
- Really more comfortable? Anyone with such a seat at home? Is it liked by both men and women?