In the GHS system, the definitions of serious eye damage and eye irritation are different.
Eye damage refers to the condition where contact with a substance or mixture results in tissue damage that is not fully reversible or a severe physiological decline in vision.
Eye irritation refers to a condition where the eye undergoes completely reversible changes after coming into contact with a substance or mixture.
In this hazard category, substances are classified into one of the following classes based on the following conditions:
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Standard |
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Category 1: Serious eye damage/irreversible eye effects |
(a) At least one effect on the cornea, iris, or conjunctiva of one animal, and the effect persists during the usual 21-day observation period. The condition will not reverse or is not fully reversible during the observation period; and/or (b) The average calculated based on the grading at 24 hours, 48 hours, and 72 hours after the test substance was dropped. A value, with at least 2 out of 3 test animals showing a positive response: (1) Corneal opacity ≥ 3; and/or (2) Iritis > 1.5. |
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Category 2/2A: Eye Irritation/Reversible Ocular Effects |
The average scores calculated based on the grading at 24 hours, 48 hours, and 72 hours after the test substance was dropped, for 3 animals. At least 2 animals in the test group showed a positive response: (a) Corneal opacity ≥ 1; and/or (b) Iritis ≥ 1; and/or (c) Conjunctival congestion ≥ 2; and/or (d) Conjunctival edema (chemosis) ≥ 2 and completely reversible within the usual 21-day observation period. |
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Category 2B: Eye irritation/reversible eye effects |
In Category 2A, if the effects listed above are completely reversible within a 7-day observation period, the eye irritant is considered a mild eye irritant (Category 2B). |
For the classification of mixtures, it can be assessed based on overall evaluation data or by applying the bridging principles. However, for mixtures, the most common scenario is to classify the mixture based on the GHS classification and content information of its components, in which case we can use the summation method for determination:
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Sum of components classified into the following categories |
Concentration of components classified into the following categories in the mixture |
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Serious eye damage |
Serious eye irritation/eye irritation |
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Category 1 |
Category 2 |
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Eye or skin Category 1 |
³ 3% |
≥ 1% and < 3% |
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Eye Category 2/2A |
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³ 10 % |
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(10 × Eye Category 1) + Eye Category 2/2A |
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³ 10 % |
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Skin Category 1 + Eye Category 1 |
³ 3% |
≥ 1% and < 3% |
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10 × (Skin Category 1 + Eye Category 1) + Eye Category 2A/2B |
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³ 10 % |
It should be noted that when classifying mixtures, we sometimes also need to consider the pH value, i.e., pH ≤ 2 or ≥ 11.5. When the mixture contains acid/alkali components or other corrosive components (Eye Category 1) with a concentration of not less than 1%, it should be classified as Eye Category 1.
For other eye irritant components (Eye Category 2) that are not suitable for the summation method and have a concentration of not less than 3%, they should be classified as Eye Category 2.
Regarding the classification of serious eye damage/eye irritation, the editor would like to share a customer issue encountered in actual work: the SDS Part 2 shows an Eye Category 1 classification and a corrosion pictogram, so why is it not classified as a Class 8 corrosive substance in Part 14?
To address this issue, we need to distinguish between GHS classification and hazardous goods classification. Class 8 - Corrosive Substances in the United Nations Recommendations on the Transport of Dangerous Goods (UN TDG) refers to substances that cause irreversible damage to the skin through chemical action or substantial damage or even destruction to other goods or transport equipment in the event of leakage. It mainly focuses on skin corrosion and metal corrosion, which is unrelated to eye damage/eye irritation.
GHS Pictogram TDG Pictogram
In SDS/label preparation, there are three key principles to note regarding the order of health hazard pictograms:
① If the skull and crossbones symbol is present, the exclamation mark should not appear;
② If the corrosion symbol is present, the exclamation mark used to indicate skin irritation or eye irritation should not appear;
③ If the health hazard symbol for respiratory sensitization appears, the exclamation mark used to indicate skin irritation or eye irritation should not appear.
Additionally, the classification of eye damage/eye irritation under GHS varies slightly across different countries and regions. The editor compares China, the United States, and the EU as a simple example.
China
According to the 'Rules for classification and labelling of chemicals—Part 20:Serious eye damage/eye irritation' GB 30000.20-2013 implemented in 2014, serious eye damage/eye irritation is divided into 3 categories, with further classification of Eye Category 2, consistent with UN GHS.
EU
Under the EU CLP Regulation (Classification, Labeling, and Packaging of Substances and Mixtures), serious eye damage/eye irritation is divided into 2 categories, and the classification of Category 2B under the UN GHS system is not adopted.
United States
In the Hazard Communication Standard (HCS) issued by OSHA (Occupational Safety and Health Administration) in the United States, the classification of serious eye damage/eye irritation is the same as China's GB30000.20, with further classification of Eye Category 2, consistent with UN GHS.
