The extensive use of chemical products world-wide necessitates the need for countries to utilize a more systematic approach in regulating their use and trade. Implementation of the Globally Harmonized System of Chemical Classification and Labelling (GHS) does exactly that; the United Nations created GHS, in hopes that different countries, would adopt a more globally recognized hazard communication program. Countries choosing to adopt GHS, will have enforced the standardized system of labelling chemical products, by including, GHS signal words, symbols, hazard statements, and precautionary statements on labels for products classified as hazardous. GHS’s 6th revised edition of The Purple Book defines GHS signal words, as usage of the words “Danger” or “Warning,” to caution users about the relative level of severity associated with products containing hazardous chemicals. “Danger” indicates hazards of greater severity, often consisting of chemicals that can be further subdivided into categories, e.g. for the ‘flammable liquids’ class, category 1 hazards are more severe than category 2, but both are attached to the signal word ‘Danger’ (this may vary depending on the number of categories in a specific hazard class). “Warning” is to be used for less severe hazard classifications and is typically assigned to chemicals that have lower category rankings, e.g. the flammable liquids class is divided into 4 categories, with “Warning” being used for chemicals assigned to categories 3 and 4. As part of the standardized format of chemical labels; GHS signal words, pictograms, and hazard statements are to be grouped together and placed in a prominently displayed location of the label. A rule of thumb when using GHS signal words is to ensure only one signal word is placed on any one chemical label; always use the signal word pertaining to the most severe hazard classification! For an in-depth summary of which informational elements are to be used for each specific hazard class, take a look at Annex 1: Classification and Labelling Summary Tables of GHS’S most current edition of The Purple Book.