GHS Classification Guidance for the Japanese Government

As for skin corrosion, classification should be conducted according to the workflow of
decision logic 3.2.1, which is the definite decision criteria of UN GHS the second revised
edition. In classification, refer to the technical advices such as judging method based on
pre-existing test data described below.
Sub-categorization of Corrosion can be performed only when an animal test is conducted that
has exposure time and observation period which allow application of the judgment of
corrosion in the UN GHS second revised edition (3.2.1). Accordingly, only for such cases,
sub-categorization is performed, and for other cases, sub-categorization should not be
performed.
In addition, note the following in classification.
* Unless a description that definitely denies hazards or recognizes extremely low hazards is
available in List 1, determination of "Not classified" should be performed carefully. If
there is any question, not “Not classified” but “Classification not possible” is preferable,
which is based on the absence of sufficient information for judging,.
* When sub-categorization is not possible, the substance shall be classified as “Category 1”.
B)Judgement by reliable existing revelation course
When a substance has cases to be judged as corrosion (any of sub-categories 1A, 1B, and
1C, or Category 1) or irritation (Category 2) in human or animal results, the substance shall be
classified as such. (Example: accidental cases)
C) Judgement by existing test data
1) Decision by in vivo test result:
■ Corrosion:(any of sub-categories 1A, 1B, and 1C, or Category 1)
In at least 1 of 3 tested animals after exposure for up to 4 hours:
a) Necrosis into the dermis.
b) Ulcer, bleeding, or bloody scabs in the applied area.
c) Blanching of the skin, complete areas of alopecia, and remaining scars are found at the
end of the observation period of 14 days.
d) In the case of erythema/eschar or edema score of 4 or more, the substance is determined
as Corrosion (Category 1)(When, however, no irreversible lesion is found, the substance
is determined as Irritation (Category 2)).
■ Irritation (Category 2)
At 24, 48, and 72 hours after application:
a) Mean value of Draize Score (for each animal) (S) is ≥2.3 to ≤4.0 for erythema/eschar or
edema in at least 2 of 3 tested animal,
b) Inflammation and alopecia of limited area, hyperkeratosis, hyperkeratosis, hyperplasia,
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