Where do I need to keep our SDS sheets?

I'm the purchasing manager at a university and we are trying to figure out where we need to keep our SDS papers for our chemicals we use. An older guy who has been here for many years says that OSHA used to require a binder of all the SDS sheets needed to be kept in at least one cleaning closet of every building. Is that still the requirement? Or could we keep them in one central location, for example at our maintenance administrative front desk? Or having them be accessible online or in a file good enough? Please advise!