copper sulfate;N'-[2-(2-aminoethylamino)ethyl]ethane-1,2-diamine

Categories

Category name:

Copper Polyamines

Justifications and discussions

Category definition:

The target substances are reaction mixtures of chelating agents (polyamines) and copper sulfate. The polyamines will form stable complexes around the copper ion.
As a group, these copper polyamines have similar physical, chemical and toxicological properties. The distinguishing feature among the copper polyamines within this category is the length of the amines and the number of ethylene groups.

See attached read-across documentation for more details.

Category description:

See attached read-across documentation

Category rationale:

REPORTING FORMAT FOR THE CATEGORY APPROACH
[Please provide information for all of the points below. Should you wish to add supporting documents, please attach the document(s) in the field 'Reports', and indicate this in the appropriate point.]

1. CATEGORY HYPOTHESIS
[Describe why the category can be formed (e.g. common functional group(s), common precursor(s)/breakdown product(s), common mechanism(s) of action, trends in properties and/or activities)]
The copper chelates considered in this category consist of two main functional groups: a copper ion (added as copper sulfate) and a poly-amine chelating agent. A substance-based read-across approach is selected, i.e. the source data come from test results obtained with one category member as such, and the results of the test is used to predict the properties of other category members. All possible toxicokinetic and toxicodynamic interactions among the source substance’s constituents are inherently reflected in the test results. In order to select the worst-case source substance, the concentration and classification of the constituents are taken into account.
See the attached report for a more detailed description.

2. CATEGORY JUSTIFICATION
[Summarise here based on available experimental data how these results verify that the category is robust]
The category approach is justified based on a range of physicochemical and (eco)toxicological endpoints. Many physicochemical endpoints were experimentally tested to prove that the substances are indeed very similar. For (eco)toxicological endpoints where no experimental information was available, a worst-case approach was used: based on available information of the constituents (GHS classification, literature data, expert judgement) the metal chelate that was worst-case (i.e. that would lead to the most stringent classification) was experimentally tested and used for the other category members.
See the attached report for a more detailed description of the category approach per endpoint.

3. APPLICABILITY DOMAIN OF THE CATEGORY
[Describe the set of inclusion and/or exclusion rules that identify the ranges of values within which reliable estimations can be made for category members]
The ecotoxicity is determined by the copper ion and the ecotoxicity of copper is expected to decrease when complexed with chelating agents because of lower copper bioavailability. Any copper chelate with polyamines where the chelating agents has stability constants similar or higher than CuDETA can thus be a category member for the ecotoxicity.
The human toxicity of the copper chelates is driven by the poly-amine chelating agents. Any metal chelate with DETA, TETA or TEPA can be considered a member of the category if the toxicity of the metal ion is lower or similar to copper.