What Is GHS?
Developed by the United Nations, GHS is a set of guidelines to ensure safe development, production, handling, transport, use and disposal of hazardous chemicals by defining health, physical, and environmental hazards of chemicals; creating classification processes from available data on chemicals for comparison with the defined hazard criteria; and communicating hazard information and protective measures on labels and Safety Data Sheets (SDSs).
Major Changes To The Hazard Communication Standard:

Hazard Classification
Chemical manufacturers and importers are required to determine the hazards of the chemicals they produce or import. Hazard classification under the new, updated standard provides specific criteria to address health and physical hazards as well as classification of chemical mixtures.

Labels
Chemicals manufacturers and importers must provide a label that includes a signal word, pictogram, hazard statement, and precautionary statement for each hazard class and category.

Information & Training
To facilitate understating of the new system, the new standard requires that workers be trained by December 1, 2013, on the new label elements and safety data sheet format, in addition to the current training requirements.

Safety Data Sheets
The new format requires 16 specific sections, ensuring consistency in the presentation of important protection information.
Identify Hazardous Chemicals and Materials
The Occupational Safety and Health Administration (OSHA) 29 CFR 1910.1200* Hazard Communication Standard is commonly known as the "Right-To-Know" standard. On March 26, 2012, OSHA revised this standard to align with the UN’s Globally Harmonized System of Classification and Labeling of Chemicals (GHS), which became effective May 25, 2012. The revised rule involves specific changes regarding Safety Data Sheets (SDSs) (formerly Material Safety Data Sheets or MSDSs), container labeling, and chemical classification. However, the underlying thrust remains the same; Employees have a need and right to know and understand the chemicals they encounter in the workplace. Compliance to this standard requires employers to develop a comprehensive program for the presence of hazardous chemicals in the workplace and to protect employees by providing them with the necessary information to properly handle hazardous chemicals.

*1910.1200(a)(1)... ensure that the hazards of all chemicals produced or imported are classified, and that information concerning the classified hazards is transmitted to employers and employees. The requirements of this section are intended to be consistent with the provisions of the United Nations Globally Harmonized System of Classification and Labeling of Chemicals (GHS), Revision 3. The transmittal of information is to be accomplished by means of comprehensive hazard communication programs, which are to include container labeling and other forms of warning, safety data sheets and employee training.