I too, have some experience in recommending emergency shower equipment to the Chemistry Department (actually the architect of the new Science building (completed ca. 2011).   Our office (EH&S) along with many other campus stake holders had an opportunity to peruse the early architectural plans for the new 5-story Molecular Sciences building  - to ask questions or make comment and suggestions.

I spotted the traditional eyewash/shower stations in all the chemistry labs and realized I had the opportunity (unsuccessfully) to induce a change in the two rooms that were to offer the organic lab sections that historically produced almost all of the department's showering events.

I have always seen two disincentives to using an emergency shower correctly (or at all):    1) the large volume of water is an issue even in a single story building, and 2)  there are privacy issues with an unclothed person in the shower.

If there were some device that could address both of these concerns then the only remaining issues would be the money involved and training of lab users on the equipment.   Turns out, there is (at least) one - which I recommended with notes added to the plan copy I had and a detailed memo to the campus architect overseeing the project.

While I am not advocating for this particular brand or model number (there may be others that will suffice) I found a shower enclosure by Hemco  (catalog number 16601)    http://www.hemcocorp.com/safetyequip.html   that provides a 5 inch deep containment at the bottom to prevent/minimize flooding in the room and a shower curtain at the front for the privacy of the patient.   ( The illustration doesn't seem to show the curtain.)