Proposed Changes to the GHS “Purple Book”, Revision 6

OSHA Hazard Communication: Hazard Classification Guidance for Manufacturers, Importers and Employers

Every two years, the UN Sub-committee releases an updated version of the official text of the GHS, commonly known as the “Purple Book.”  In 2015, they will release the sixth revision. Among the changes that are expected to be in the sixth revision are new physical hazard classes and hazard categories, guidance for the physical properties in section 9 of the safety data sheet (SDS), and example of labeling on small packaging.

New Hazard Classes and Categories

There are two new hazard classes that are proposed to be added in the sixth revision of the purple book. The first is a new hazard class for desensitized explosives. Desensitized explosives are explosive substances and mixtures that are wetted with water or alcohols or diluted with other substances to suppress their explosive properties.The new category is likely to be added to the existing 6 divisions of the explosives categories under physical hazards.

The second is a new hazard class for pyrophoric gases which will likely be added as a subcategory of the flammable gas category. The U.S. OSHA Hazard Communication Standard has covered pyrophoric gasses in the workplace since the 1980s, and the proposed UN GHS amendment will be similar in scope to the HCS definition.

Guidance, Clarifications, and Corrections

The UN Subcommittee has proposed comprehensive guidance for section 9 which contains information on the physical and chemical properties of a product. This includes guidance on mandatory properties, physical properties related to classification criteria, and additional properties that may be of interest to downstream users. In addition, there will be PCI editorial revisions and precautionary statement corrections.

Labeling on Small Packages

A GHS label is comprised of a product identifier, supplier identifier, as well as standardized pictograms, a signal word, hazard statements, and precautionary statements. This is problematic for many chemicals, such as pharmaceuticals, that may be packaged in containers as small as 5 mL vials or 50mL bottles. In a recent Letter of Interpretation2, OSHA clarified its requirements for small containers. Although there still must be chemical information on the label attached to the chemical’s immediate package, OSHA will allow pull-out labels, fold-back labels, tags or other methods. Additionally, when these options are not feasible, OSHA requires the following information be added to the small label, at a minimum: product identifier, appropriate pictograms, manufacturer’s name and phone number, signal word, and a statement indicating the full label information for the chemical be provided on the outside package.

In the next edition of the “Purple Book”, the UN Subcommittee will provide additional guidance on placing a GHS compliant label on small containers of hazardous chemicals by providing an example of labeling.

Example of labeling on immediate container with minimum GHS label requirements:3

sample GHS small label

Adoption and implementation of the proposed updates will vary among countries. In the U.S., OSHA is exploring the potential changes to maintain alignment with GHS. Proposals will be limited in scope to only amend the provisions of the Hazard Communication Standards (HCS) that must be changed to maintain alignment with GHS.

1 Comparison of Hazard Communication Requirements OSHA Hazard Communication Standard 29 CFR 1910.1200 (HCS) Globally Harmonized System (GHS).

2Letter of Interpretation – Standard Number 1910.1200. OSHA.

3Ruskin, M. (2014). GHS Update [PowerPoint slides].