In the previous discussion on GHS pictograms, we covered the graphic symbols and their correspondence to GHS hazard classifications. When a substance or mixture has multiple GHS hazard classifications, several pictograms may be needed on the label. In such cases, it's necessary to check the priority order of the pictograms.
For substances and mixtures within the scope of the UN Model Regulations, the order of physical hazard symbols should follow the rules of the UN Model Regulations. For those outside this scope, the order can be determined as needed.
Regarding health hazards, the following priority principles apply:
- If the skull and crossbones (GHS06) appears, the exclamation mark (GHS07) should not.
- If the corrosion symbol (GHS05) is present, the exclamation mark (GHS07) for skin or eye irritation should not appear, but it must still be used for other hazards.
- If the health hazard symbol for respiratory sensitization (GHS08) is present, the exclamation mark (GHS07) for skin allergy or skin/eye irritation should not appear, but it must still be used for other hazards.
In addition to priority rules, GHS label information placement is also specified. GHS pictograms, signal words, and hazard statements should be grouped together on the label.
National authorities often set pictogram size requirements similar to those for transport pictograms, referring to the red frame of the pictogram itself. For example, the EU requires each hazard pictogram to cover at least 1/15 of the minimum required information label surface area, with a minimum GHS pictogram area of 1 square centimeter.
