GHS Cut-off Value and GHS Concentration Limit
By Little Pro on 2016-01-06 Views: Update:2018-02-09
GHS cut-off value or GHS concentration limit is the minimum concentration for a hazardous substance to trigger the classification of a mixture containing it. They are mainly expressed as % thresholds and are primarily used for mixture classification under GHS.
The table below is an example of cut-off value/concentration limit for hazard class skin corrosion/irritation. If a mixture contains a hazardous ingredient that has been classified as skin corrosive category 1, the mixture itself will also be classified as skin corrosive category 1 if the concentration of ingredient exceeds 5%.
In GHS, the cut-off value and concentration limit are equivalent and meant to be used interchangeably. It shall be noted that the EU CLP regulation has given different definitions to cut-off value and concentration limit. In addition to that, Europe has set specific concentration limits for specific substances.
- Cut-off value: minimum concentration for a substance to be taken into account for classification purposes(do not necessarily trigger classification);
- Concentration limit: minimum concentration for a substance to trigger the classification of a mixture for a specific hazard class;
- Specific concentration limit: a concentration limit that is specific to a substance and takes precedence over generic concentration limit or cut-off value.
Special Considerations When Using GHS Cut-off Value and GHS Concentration Limit
There are some special considerations when using cut-off value and concentration limit to classify a mixture:
- Rule 1: Test data always takes precedence over cut-off value/concentration limit;
- Rule 2: If a mixture contains two or more ingredients with the same or similar hazards, the concentration of the hazardous ingredients shall be added first. However, this additivity principle does not apply to non-additive hazard classes and categories.
- acute toxicity;
- skin corrosion/irritation;
- serious eye damage/eye irritation;
- specific target organ toxicity, single exposure category 3 (respiratory tract irritation);
- specific target organ toxicity, single exposure category 3 (narcotic effects); and
- acute and chronic aquatic hazards.
- skin and respiratory sensitisers;
- germ cell mutagenicity;
- reproductive toxicity;
- specific target organ toxicity, single and repeated exposure, categories 1 and 2;
- aspiration hazard;
- skin corrosion/irritation in special cases (strong acid and base); and
- serious eye damage/eye irritation in some special cases (i.e., strong acid and base).
Generic GHS Cut-off Values for SDSs
GHS has also set generic cut-off values for SDSs. An SDS should be prepared and provided for a substance or mixture meeting classification criteria or for a mixture containing a hazardous ingredient with a concentration exceeding the cut-off limits given in the table below.
Reference & Resources
Topics - GHS, GHS Research and Tutorials