Here is an excellent resource:

http://www.osha.gov/dsg/hazcom/side-by-side.html

Here is an excerpt from an article at:

http://ohsonline.com/articles/2012/06/01/osha-adopts-ghs.aspx

Fourth HazCom 2012 Deadline: June 1, 2016 (Employers)

By this date, employers must be fully compliant with OSHA's adoption of GHS. They must complete any necessary updates to their hazard programs and workplace labeling procedures, and all affected employees must be trained on any new hazard or safety procedure identified during the chemical reclassifications done by manufacturers and distributors.

As with the employee training on how to read GHS formatted SDSs and labels, employers may not wish to wait until the deadline before getting into full compliance. Either way, at no time will employers be exempt from complying with either the old HCS or the new (or some combination of the two). In other words, employees must not lose any of the protections they had under the old HCS.

Many employers have questions about how to best produce HazCom 2012-compliant workplace labels (also called secondary container labels or in-plant labels).This is one area where OSHA is a little more flexible. Employers can continue to use their current workplace labeling systems so long as they take into account new hazard classifications. In other words, workplace labels will continue to be performance based. HazCom 2012 does not specify for employers exactly what has to be on the label. Instead, it tells employers the effect the labels must achieve in regards to providing employees important hazard information. What OSHA says is that the workplace label must provide the same understanding for employees that a shipping label would.

OSHA says employers can either replicate the hazard information found on the shipping label or use "some combination" of the elements (product identifier, signal words, pictograms, hazard statements, precautionary information), which, along with training, achieve the same affect. A way to think about it would be the equation: workplace label + training (must) = shipping label. Best practice is to replicate the information found on the shipping label, which is something a good secondary labeling system can easily do. This, of course, not only provides the best information for employees, it also provides the most compliance coverage for employers.

From the standard:

(f) Labels and other forms of warning.

The HCS is designed to provide

information through three different

media: labels or other forms of

immediate warning; safety data sheets;

and training. Labels are attached to the

container of chemicals, and thus

provide the information that employees

have the most ready access to in the

workplace. Given that they are attached

to containers, they are by necessity

somewhat limited in the amount of

information they can present. The labels

provide a snapshot or brief summary of

the more detailed information provided

to employees in training programs, or

available to them on safety data sheets.

They are not intended to be a complete

or detailed source of information on the

chemical.

In the current HCS, the requirements

for labels are performance-oriented

Also

The current HCS similarly requires

identity and appropriate hazard

warnings for in-plant containers. OSHA

has taken a flexible approach to in-plant

labeling, allowing a wide variety of

systems to be used as long as all of the

required information is readily available

to employees when they are in their

work areas. Thus the current standard

allows employers to continue to use

systems such as the Hazardous

Materials Information System (HMIS)

and the National Fire Protection

Association (NFPA) labeling systems

that use numerical rankings of hazard.

We plan to continue to use the NFPA system.

Hope this helps,

Jeff Tenney