Slags, ferronickel-manufg.

Endpoint summary

Additional information

Ames test was performed on five S typhimurium strains (TA 98, TA 100, TA1535, TA1537 and TA102) with or without metabolic activation according to OECD 471. The test item was diluted either in 0.9% NaCl in water ir in DMSO to final concentrations of 10, 20, 40, 60, 80 and 100%. No toxic effects were noted in all tester strains at all concentrations in experiment I (with Aqua dest) and in experiment II (with DMSO). No biologically relevant increase in revertant colonies were observed following treatment with polar or non-polar extracts of the test item at any concentration level neither in the presence or absence of metabolic activation. The reference mutagens caused a distinct increase confirming the validity of the experiment. It can be deduced that the test item is not mutagenic for bacteria under the present experimental conditions.

A test item extract of Slags, ferronickel-manufg./Electric Furnace Slag/ Converter Slag was investigated for a possible potential to induce micronuclei in Chinese hamster V79 cells in vitro in the absence and presence of metabolic activation with S9.

The test item was extracted in cell culture medium at a weight/volume ratio of 0.2 g/mL for 72 h ( 2 h) at 37 °C ( 1 °C) according to ISO 10993-3, 2003 and ISO 10993-12, 2007. The extract was centrifuged at room temperature for 5 minutes at 1000 g. The test item extract was diluted in cell culture medium prior to treatment and the pH of the solution was adjusted to 7.0.

In experiment I with and without metabolic activation 100% Extract was selected as highest dose group for the microscopic analysis of micronuclei.

In experiment II without metabolic activation 80% Extract was selected as highest dose group for the microscopic analysis of micronuclei. The following concentrations were evaluated:

Experiment I with short exposure (4 h):

with and without metabolic activation: 60, 80 and 100%

Experiment II with extended exposure (24 h):

without metabolic activation: 20, 40, 60 and 80%

In the main experiment I with and without metabolic activation no biologically relevant increase of the micronucleus frequency was noted after treatment with an extract of the test item. In the main experiment II without metabolic activation no biologically relevant increase of the micronucleus frequency was noted after treatment with an extract of the test item.

The nonparametric test was performed to verify the results in both experiments. No statistically significant enhancement (p<0.05) of cells with micronuclei was noted in the dose groups of the test item extract evaluated, except for the test item extract concentrations of 20% and 60% in experiment II without metabolic activation. These values were significantly increased compared to the corresponding negative control. However, the micronucleus frequencies were within the historical control data range of the negative control and no dose-response relationship could be observed.

Based on these data, the number of micronucleated cells found in the groups treated with the test item did not show a biologically relevant increase as compared to the corresponding negative control.

Ethylmethanesulfonate (EMS, 900 and 600 μg/mL) and Cyclophosphamide (CPA, 2.5 μg/mL) were used as clastogenic controls. Colcemide (0.08-0.8 μg/mL) was used as aneugenic control. All induced distinct and biologically relevant increases of micronucleus frequency. This demonstrates the validity of the assay.

The fine particle fraction of various grades of Ferronickel Slags was analysed with XRD using Rietveld quantitative phase analysis to determine the respirable crystalline silica (RCS) content. As a result no RCS was detected, so it is safely assumed that the SiO2 in the substance is amorphous.

The chromium species were determined via XRD analysis. No hexavalent Chromium species were present up to the limit of detection of the analytical method (20mg/kg) so all Cr in the substance is considered to be in trivalent form.

Short description of key information:
Slags, ferronickel-manufg was found to be non-mutagenic for bacteria in an OECD 471 bacteria reverse mutation test and did not induce structural and/or numerical chromosomal damages, in an OECD 487 In vitro Micronucleous Test, in Chinese hamster V79 cells.Therefore, an extract of Slags, ferronickel-manufg is considered to be non-mutagenic.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Slags, ferronickel-manufg was found to be non-mutagenic for bacteria in an OECD 471 bacteria reverse mutation test and did not induce structural and/or numerical chromosomal damages, in an OECD 487 In vitro Micronucleous Test, in Chinese hamster V79 cells.Therefore, an extract of Slags, ferronickel-manufg is considered to be non-mutagenic and, therefore, no classification in regards to its mutagenicity is required, according to the CLP regulation.

Furthermore, no Respirable Crystalline Silica (RCS) or hexavalent Chromium was detected in analyses via XRD with Rietveld analysis and colorimetry after digestion, respectively, so no genetic toxicity can occur from these factors.