@fulhamish:
"How far do you push this envelope [of separate facilities in the workplace]? Race, sexual orientation, religion....where do you make your stand?"
I'm not an expert on workplace law or sexual discrimination with respect to facilities. I know from my decades of experience in the workplace, but I'm willing to be educated more. My quick research didn't yield as much as I'd like to know. I'm sure there are many complications and nuances that a single post on this forum couldn't answer.
If the numerical minority in a science lab (probably fewer females than males) wanted separate facilities and the majority assented, I'd think it might be worth exploring the idea as long as resources were allocated fairly (tough to monitor and prove--Reagan's "trust but verify" is a problem-laden maxim). If the majority wanted to impose on the minority, then that wouldn't fly at all. Lawsuits would follow.
I've worked closely with people of every sex, skin tone, ethnicity, religion, political party, veteran status, felon status, and sexual orientation. I kind of don't really see a rationale for considering separate facilities for any of those categories, mainly because there is no difference as far as the workplace is concerned.
I rather think that any "separate but equal" under the same umbrella (school district, state, nation, company, corporation) is doomed to fail though. The only way to legally separate is with memberships, but that is completely different.