By Little Pro on 2016-01-06 Views: Update:2017-01-18
For a hazardous chemical classified with multiple hazards, it is very important that we use prioritized GHS pictogram, signal word or hazard statements to communicate the most significant hazards first. In this article, we have summarized main GHS precedence rules for pictogram, signal word, hazard statement and precautionary statements. We hope that you find this article helpful.
For physical hazards, the pictograms (labels) prescribed by the UN Model Regulations on the Transport of Dangerous Goods (TDG) should be used. If a transport pictogram appears on the package, the GHS pictogram for the same hazard should not appear.
For health hazards: Exclamation mark should not appear if:
The picture below summarizes GHS pictogram precedence.
If "Danger" is used, "warning" should not appear. Only one of them needs to appear on a label.
All hazard statements should appear on a GHS label, except those as specified below:
Even though different competent authorities may decide whether to use above precedence rules or not, most of countries have adopted above rules when implementing GHS.
There is no standard precedence rule for precautionary statements in UN GHS. You may include all precautionary statements on a GHS label (code is unnecessary). However, many competent authorities (EU, Korea, and Australia) have limited the number of precautionary statements on a label to make a label more readable. In this case, you have to learn how to select the most relevant precautionary statements on a label. This is particularly important if you are preparing a label for a chemical classified with multiple hazards or if you wish to save some space on a label.
ECHA's guidance on classification and labelling has classified all precautionary statements into four categories: highly recommended, recommended, and optional and not to be used. Normally you can include highly recommended or recommended ones.
The picture below shows how precautionary statements are categorized for a flammable liquid in ECHA's guidance. If you wish to read more, please click the picture to download the guidance.