A couple of weeks ago, Glenn Demby asked for writers to submit articles describing the Global Harmonized System (GHS) for hazard communication. I decided to answer the call. I don’t consider myself anything like a first rate author. But I am familiar with the GHS. So I’m going to take a crack at explaining what it’s all about.

How GHS Came About

Most of the world’s industrialized nations have established a system of chemical hazard regulation that, among other things, requires manufacturers, suppliers and employers to communicate information about the physical properties and dangers of hazardous substances to workers and consumers. (Note: Through the course of this article, when I refer to “substances,” I mean not just pure substances but mixtures.) In the U.S., the system is known as HAZCOM; in Canada it’s called WHMIS.

Although the various national schemes are similar to one another, they contain certain inconsistencies, especially with regard to safety data sheets and the labeling of hazardous substances. For example, there are some significant differences from country to country in requirements regarding the types of warning labels and Material Safety Data Sheets. These differences in requirements have proven confusing and have encumbered the transaction of global business.

So, in the mid-1980s, the International Labor Organization called for a development of a uniform standard that could be followed globally. The United Nations responded in 1992 by proposing GHS--the Global Harmonization System of Classification and Labeling of Chemicals.

What GHS Is

GHS is an international system designed to standardize the communication of hazardous substances according to their health, environmental and physical hazards. In developing GHS, the UN reviewed existing national and multinational systems and formed a nucleus of a new system around their features. GHS is largely based on:

HAZCOM and WHMIS (especially requirements on the use of labels and MSDSs to notify workers and consumers of hazardous properties of substances);
The EU (European Union) system for preparation, classification and labeling of substances; and
The UN Transportation of Dangerous Goods system for communicating hazards.
Conclusion

Now that I’ve put GHS into context and explained what it is, we need to talk about its features and how it works. I’ll do that in next week’s issue. So thanks for listening and stay tuned.

I'd like to continue discussing the Global Harmonized System (GHS) for hazard classification and communication. I want to acknowledge that the following information comes from the United Nations website.

Purpose of the GHS

As noted last week, the GHS is an attempt to harmonize criteria for the classification of substances and mixtures according to their physical, health and environmental hazards as well as for communication elements (including requirements for labels and safety data sheets). The UN lists the purposes of the GHS as:

Enhancing the protection of human health and the environment by providing an internationally comprehensible system for hazard communication;
Providing a recognized framework for countries without an existing system;
Reducing the need for testing and evaluation of chemicals; and
Facilitating international trade in chemicals whose hazards have been properly assessed and identified on an international basis.
Scope of the GHS

The GHS is intended to benefit persons exposed to hazardous substances including consumers, workers and emergency responders. The GHS has two main elements: hazard classification and hazard communication.

Hazard Classification: GHS classification uses four sub elements:

Health hazards;
Environmental hazards;
Physical hazards; and
Mixtures
Hazard Communication: Like WHMIS in Canada and HazCom in the U.S., the GHS hazard communication scheme involves the use of labels and safety data sheets. (Note: The latter are referred to as "safety data sheets," not "material safety data sheets." The "M" has been dropped from the "MSDS.") GHS labels are similar to but not exactly the same as WHMIS and HazCom labels. The major difference: GHS labels use health and environmental warning symbols. (You can view the new warning pictograms at http://www.unece.org/trans/danger/publi/ghs/pictograms.html )

The Adoption of GHS

Note that GHS is about classification and communication of hazards. It's not about risk management. For example, it doesn't recommend exposure limits that should be adopted for various substances. Nor does it say how consumers and workers should be trained. The adoption of exposure levels, training requirements and other risk management and operational details is left to each country.

Ultimately, each country must decide which, if any, of the GHS classification and communication elements to adopt. Countries like Canada and the U.S. can integrate GHS into their current regulatory schemes. Countries that don't have full blown schemes can build a regulatory regime around the GHS elements if they choose.

Caveat: Countries must ensure consistent application of the GHS elements that they do adopt across their systems. For example, if a national system covers the carcinogenicity of a chemical, it should follow the GHS's harmonized classification scheme to classify it and its harmonized label elements to communicate its dangerous properties. Allowing for inconsistencies from nation to nation would undermine the GHS goal of international harmonization.

Conclusion

I hope this little summary gives you a feel for what GHS is all about. If you want more information, I suggest you visit the UN website: http://www.unece.org/trans/danger/publi/ghs/ghs_rev01/English/01e_part1.pdf.