GHS Classification Guidance for the Japanese Government

Grounds” with “No established test method suitable for low-temperature boiling Liquids”. In
the case of solid with a melting point of higher than 55°C, fill in “Classification result” with
“Classification not possible” regarding “Corrosive to Metals”, and fill in “Classification
Grounds” with “No established test method suitable for Solid substances”. For all cases
mentioned above, it is also permissible to simply indicate “No data.”
2) In case of “Classification not possible” because of lack of data
For hazard items that cannot be classified by the above procedure, fill in “Classification
result” with “Classification not possible”, and fill in “Classification Grounds” with “No
data”.
(4)Data availability
Few numerical data on metal corrosion rate have been published.
(5)Comparison with conventional classification systems
The definition completely accords with that of the Class 8PkgIII “Metal corrosivity” described
in UNRTDG2.8.2.5(c)(ii).
(6)Sources of information for classification results under conventional systems
Since metal corrosivity is classified into UNRTDG Class 8 along with skin corrosivity, whether
a substance has metal corrosivity or not cannot be judged from the fact that the substance is
classified in Class 8. Metal corrosivity thus cannot be attributed to a substance based on
“Dangerous Goods Regulations Annex 1” alone. Therefore, a substance that clearly has metal
corrosivity shall be classified into this class. If it is not clear whether a substance has metal
corrosivity, indicate “presumed” on the label for the substance.
GHS classification is based on UNRTDG, which was developed in relation to the leakage
treatment of substances. It should be noted that even if a substance does not fall under this class, it
still has a possibility to give damage to a container or pipe for storage or use.
In the test of metal corrosivity, metal pieces (steel and aluminum) are immersed in a liquid
(55°C) for 7 to 28 days, and if the corrosion length gets to 6.25 mm (annualized value) or more,
the liquid is judged corrosive. As mentioned above, this criterion for corrosivity was defined in
light of the risk that the leakage of a liquid gives damage to a container of transport equipment or
other freights when the leakage is not immediately treated. Thus, a different criterion should be
applied when determining whether or not a metal can be used for the container or pipe of the
liquid. If a liquid is corrosive, even if to a minimal extent, the use of a metal for its container
impairs the liquid. In the definition of metal corrosivity in GHS, such a kind of criterion has not
been adopted.
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