What are the WHMIS ranges and what do they represent?

Because of the privacy of the specific chemical make-up of a product, companies do not want the exact concentration percentage of a chemical listed on the MSDS sheet. Therefore, WHMIS ranges are used to protect this classified information. The WHMIS range withholds the true concentration of the chemical in regards to the controlled product.

When the concentration of an ingredient is expressed as a percentage, the percentage should be an expression of the ratio of the weight of the ingredient/complex mixture to the weight of the controlled product, the volume of the ingredient/complex mixture to the volume of the controlled product, or the weight of the ingredient /complex mixture to the volume of the controlled product.

There are eleven WHMIS ranges that can be used to represent the concentration of a chemical in a controlled product.

1.1to 1 percent
0.5 to 1.5 percent
1 to 5 percent
3 to 7 percent
5 to 10 percent
7 to 13 percent
10 to 30 percent
15 to 40 percent
30 to 60 percent
40 to 70 percent
60 to 100 percent

Any of these ranges can be used to represent the true concentration of an ingredient/complex mixture in regards to the controlled product, given the true percentage falls into the range given.

What is a CAS number?

Chemicals are listed on MSDS sheets, along with their assigned CAS number.

CAS Registry numbers are assigned to each chemical by the Chemical Abstracts Service (CAS), a division of the American Chemical Society. Each number is a unique identifier for a chemical substance and can apply to only one. These numbers have no underlying chemical significance but provide a systematic way to identify a chemical substance or molecular structure, regardless of the many names that may be applied to that ingredient.

Each CAS registry number has three parts separated by hyphens, up to a maximum of ten digits. The first part contains up to seven digits, the second contains two digits, and the third part is always one digit (the check digit). The numbers themselves are simply assigned in increasing order and have no inherent meaning.

CAS numbers can apply to many different substances including alloys, chemical elements and compounds, minerals, mixtures, polymers, salts and biological sequences.

The CAS registry numbers are taken from the CAS registry, which is a database of these chemicals. The database is updated every day, with roughly 12,000 new substances added daily.

CAS registry numbers are used on MSDS sheets because they are unique to each substance and are internationally recognized. These numbers are the standard when identifying a chemical because of the many different ways that a chemical can be labelled, including by their molecular formula, generic names, or trivial names. Having a CAS number ensures you are using the correct chemical information at all times.

Globally Harmonized System (GHS)

The Globally Harmonized System of Classification and Labeling of Chemicals (henceforth GHS) is a system intended to provide a uniform means of classifying chemicals by hazard type. The use of a standard format for communicating hazards posed by chemicals is meant to facilitate the production and trade of potentially hazardous substances. The regulations comprising the system were first published in 2003, and are currently in their third revision, published in July 2009.

The Globally Harmonized System of Classification and Labeling of Chemicals or GHS as it is commonly referred to as, is an internationally agreed on classification of chemicals. The aim of the GHS is to provide universal regulations and guidelines for chemical labeling, documentation and use on a global platform.

The chemicals are classified by types of hazard. The purpose of the harmonized system is to ensure the toxicity and hazard information associated with these chemicals are available to promote the safe transportation, handling and use of these chemicals. The harmonized system also increases environmental safety as well as promoting the protection of human health.

The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is a new system that classifies chemicals by their types of hazard. The GHS introduces harmonized hazard communication elements which includes labels and safety data sheets.

To ensure the protection of human health and the environment during the transportation and use of these chemicals, the GHS was developed to display the information on physical hazards and toxicity from chemicals on dangerous products. It also provides a basis for the harmonization of rules and regulations on chemicals at a national, regional and worldwide level. This system is a key factor that facilitates trade between organizations. The GHS’ primary audiences include the government, regional institutions and international organizations. Not to mention that it also contains sufficient context and guidance for those in the industry who are willing to implement this unique system on their products.