In a letter dated June 13, 2014 the US Department of Labor, OSHA clarified it’s position regarding the new GHS for classification of chemical stating that “employers
may, but are not required to, contact manufacturers or distributors of products they have previously ordered to request new SDSs“.
What OSHA is saying is that if you have chemicals in your facility that date back before the implementation of GHS, the MSDS sheet is all that is required, OSHA will not issue a citation. If, however the chemical was purchased or brought in after the implementation of GHS than it should have come with the new SDS rather than the MSDS and that SDS is what needs to be on file.
The letter of clarification was issued in response to a question submitted to OSHA. The full letter can be viewed here.