Acetic acid, chromium salt, basic

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Acetic acid, chromium salt, basic is an organic-metal salt that is composed of trivalent chromium (Cr³⁺) and and acetate group (CH₃COO^-). Thus, a PBT assessment based on the criteria set out in the "Guidance on information requirements and chemical safety assessment, Chapter R.11. PBT Assessment (ECHA 2012)” is not fully applicable to the substance. Nevertheless for persistence, bioaccumulation, and toxicity the following conclusions can be drawn:

Persistence Assessment:

For the inorganic chromium ion the approach of persistence assessment is not applicable. The organic molecular (acetate) group is readily biodegradable according to OECD 301A. Therefore, the test substance does not have potential of persistence according to the screening criteria of P and vP. 

 

Bioaccumulation Assessment:

For the inorganic chromium ion, the approach of persistence assessment is not applicable. Chromium (III) is essential for regular operation of human vascular and metabolic systems. For this case, removal and sequestration processes that minimize toxicity are complemented by an ability to regulate concentrations for essentiality. As the result that concentrations of essential mineral nutrients in organisms tend to be highly regulated, such essential metals do not need to be classified as “bioaccumulative”. The potential of bioavailability of chromium (III) is generally low. The availability is basically depending on the existing pH-regime. Due to the precipitation, as well as the adsorption processes, chromium (III) transforms easily into sediment or soil compartments, where the bioavailability to aquatic organisms is reduced significantly during the environmental ageing process. Furthermore, the bioavailability of chromium (III) is restricted by physiology in case a biotransformation occurs, as most chromium (III) compounds are normally not possible to cross cell membranes as reported in a 2-year study uptake of chromium (III).

The acetate goup is the only organic molecule present in the test substance. As it is readily biodegradable and easily meatbolised in organisms, the test substance is not considered to have potential of bioaccumulation in accordance with the screening criteria for B and vB. 

 

Toxicity assessment:

Only acute aquatic toxicity studies are available for the test substance showing LC/EC50 as well as NOEC values > 100 mg/L. Therefore the test substance can be regarded as presumably not T.

Furthermore, the test substance is not classified as CMR nor exhibits any other evidence for chronic toxicity according to Directive 67/548/EEC and Regulation (EC) No. 1272/2008 (2nd ATP) based on the available data.

Regarding the T screening assessment, assigning of “T” cannot be absolutely excluded due to the limitation on data requirement. However, as the screening criteria for P and B are not met, no further assessment is necessary