It would probably come under an equal rights for all employees textbook. Something that states the rights of all employees, from different sexes, races, ages, religions, people with disabilities etc. It is against the law (here in uk anyway!) to discriminate against anybody for things like this. I know ocd isnt a disability as such or anything but it is still a condition that needs to be taken into account and you cannot be discriminated against for having it. Only if having ocd will really hinder the job that you would be doing would you probably not be able to work in a certain job!

All employers should have a copy of an equal rights for employees handbook, particularly large employers, but if they dont you should be able to get one off the internet or maybe a library? Or maybe you could just try typing in equal rights for employees on the internet and see what comes up there! They probably document the text online so that it is accessible for everyone!!

Hope this helps a little!! :)