Sulfuric Acid, waste gas washing, copper smelting

Endpoint summary

Description of key information

- complex metal containing substance
- solubility of metal constituents is poor
- classification via mixture toxicity rules

Additional information

The UVCB substance is a complex metal containing substance. Each individual (metal) constituent of this UVCB substance can release soluble ions that can contribute (as ‘relevant’ component) to the mixture toxicity. With knowledge of the elemental composition (IUCLID section 1.4 & 1.2) and mineralogical information on a representative sample (IUCLID Section 4.23), the mixture toxicity rules (EU CLP Guidance Annex I: Annex I: 3.9.3.4, and cut-off) was used to calculate the Classification of the UVCB substance.   

The Arche CLP tool was used to automatically calculate the classification of the intermediate. The tool is based on a database containing the human and environmental classification for each component relevant for classification. The information on the representative mineralogical composition (distribution pattern for each constituent of the UVCB substance) is furthermore incorporated into the tool, so that the elemental composition (in % Total element) is automatically converted into % w/w of compounds that are relevant for applying the Sum/add formula.

Justification for classification or non-classification

Specific Target Organ Toxicity (repeated): not classified

Specific Target Organ Toxicity (single): not classified

The classification derived is applicable to all Sulphuric acid, waste gas cooling and cleaning, copper smelting. 

The tested sample is representative for a worst case , defined within the concentration ranges outlined under IUCLID section 1.2

Self-classification of the UVCB substance (IUCLID Section 2.1 & 2.2) was performed based on below outline:

1. Characterization

The material is accurately described from its chemical/ elemental composition (concentration ranges across production sites –IUCLID Section 1.2), and the specific speciation data (mineralogical information, hazard) obtained from a representative sample (IUCLID Section 4, in particular 4.23). This information is enough to initiate the classification process.

2. Classification by the Mixture Approach

The UVCB is treated as a complex metal containing substance with a number of discrete constituting compounds (metals, metal compounds, non-metal inorganic compounds). The hazard classifications of each compound is then factored into a combined classification of the UVCB as a whole. For health endpoints, UVCB classifications are based on the combined hazards of the compounds whereby additivity or key cut off levels, specified in look-up tables are used, depending on the endpoint and amount of information available for the constituting compounds. For environmental endpoints, additivity and/or summation algorithms are applied to quantitatively estimate the mixture’s toxicity to aquatic organisms. These concepts and rules are incorporated in easy to use IT tools, which can be used to classify the UVCB.

3. Bridging or Read-Across

(Eco)-toxicological data are not available for the specific UVCBs being evaluated. Considering the knowledge and variability in composition, read-across and bridging is done by using  a "representative" mineralogical/speciation analysis"  combined with the  "worst case" metal concentration (across companies)  as a basis for the classification of the UVCB substance (chemical and mineralogical surrogates with similar origin/production process and physical/chemical properties –see IUCLID 1.4 for information on Sampling procedure).

4. Eventual correction

No correction for (bio)availability was made

 

See furthermore attached documents:

• Arche CLP tool version June 2010
• Incorporated to tool (or attached): how elemental composition is translated into Mineralogical composition relevant for classification (i.e. “ input sheets”)