Sodium diethyldithiocarbamate

Endpoint summary

Description of key information

According to Section 8.1 Column 2, Annex VII of REACH Regulation chemicals that are strong bases (pH>11.5) may be classified as corrosive to the skin. Anhydrous (pure) SDEC has an alkaline pH (>11.5) and hence, a classification for skin corrosion is warranted. Accordingly, its marketed form i.e. 26% aqueous solution SDEC may also be classified for skin corrosion, since it exceeds the generic concentration limit of ingredients for skin corrosion that trigger classification of a mixture (>5%), as laid down in CLP Regulation (EC) No 1272/2008. This approach is further confirmed by experimental data: an in vitro percutaneous absorption study with SDEC in its manufactured and marketed form (as ca. 26% aqueous solution) showing damaging effects of the test material to the isolated human skin in vitro. 

Similarly, according to  Section 8.1 Column 2, Annex VII of REACH Regulation chemicals that are strong bases (pH>11.5) may be classified as damaging to the eye. This is applicable for the anhydrous (pure) SDEC given its alkaline pH (>11.5). Accordingly, its marketed form i.e. 26% aqueous solution SDEC may also be classified as eye damaging, since it exceeds the generic concentration limit of ingredients for irreversible eye effects that trigger classification of a mixture (>3%), as laid down in CLP Regulation (EC) No 1272/2008.

It is therefore, considered acceptable to conclude that both the anhydrous and the 26% aqueous solution SDEC may be corrosive to the skin and eye damaging. Consequently, the performance of a skin corrosion/irritation and an eye irritation study is not necessary.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Additional information

In the percutaneous absorption study with SDEC, isolated human skin was exposed during 24 hours to the undiluted (as manufactured) SDEC solution (23.4% SDEC solution) and as 10% dilution (2.34% SDEC solution) to study skin penetration. The 100% solution and the 10% solution interfered with the barrier function of the skin which can be concluded from the data were the relative absorption (percentage of the amount of substance exposed to the skin) for the 100% solution is higher than the relative absorption for the 10% solution. Furthermore, tape stripping was extremely difficult as a result from the damaging effect of the test solutions on the stratum corneum, which was already observed during washing after 8 hours of exposure. 

Justification for classification or non-classification

Skin irritation: based on the alkaline pH and the results of the skin penetration study, both the anhydrous (pure) SDEC and its 26% aqueous solution shall be classified as corrosive to the skin (Skin Corr. 1A, H314), according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

Eye irritation: based on the alkaline pH, both the anhydrous (pure) SDEC and its 26% aqueous solution shall be classified as damaging to the eye (Eye Dam.1, H318), according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.