Sulfuric Acid, waste gas washing, copper smelting

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: non GLP but other Quality Assurance

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

other: software

Title:

Unnamed

Year:

2010

Materials and methods

Principles of method if other than guideline:

Aquatic toxicity of the UVCB substance was determined by classifying based on Mixture rules from EU CLP (Lower Tier= summation of classified components to derive Hazard class) and back calculation to the corresponding L(E)C50 range.

GLP compliance:

no

Remarks:

other Quality Assurance

Test material

Test material information

Constituent 1

Reference substance name:

sulfuric acid hydrate

EC Number:

922-670-1

IUPAC Name:

sulfuric acid hydrate

Details on test material:

Worst case (maximum across industry) as defined in iuclid section 1.2;
See IUCLID Section 1.4, for company specific elemental composition; and representative sample for mineralogical information (IUCLID Section 4.23 -Outotec report)
Representative copper speiss - randomly collected from production over long period, crushed and homogenised.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

<= 1 mg/L

Nominal / measured:

estimated

Conc. based on:

dissolved

Basis for effect:

not specified

Effect concentrations 2

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

<= 1 mg/L

Nominal / measured:

estimated

Conc. based on:

dissolved

Basis for effect:

not specified

Any other information on results incl. tables

The calculated classification via Summation method (lower Tier Arche CLP Tool) resulted in a "Hazardous to aquatic Environment Chronic Category 2" classification for the UVCB substance.

Based on this result, the related criteria provided the estimated value for toxicity to aquatic algae (see EU CLP Guidance Annex I Table 4.1.0): 72 or 96 ErC50 (for algae) >1 to < or equal 10 mg/l.

Applicant's summary and conclusion

Conclusions:

Study can be used as lower tier (conservative) to predict the EC50 (algae) and to classify the UVCB substance.

Executive summary:

The study provided a conservative estimate of the EC50 (for crustacea), derived on basis of the Classification outcome (Mixture toxicity rules) from a representative C opper Speiss as defined in IUCLID section 1.4/4.23. The result is applicable to all Sulphuric acid, waste gas washing and cooling from copper smelting that fall under the defined concentration ranges (IUCLID section 1.2).

Validity of the model used:

1. defined end points: aquatic toxicity (acute & chronic)
2. unambiguous algorithm from EU CLP Guidance: summation/additivity formula to determine Classification and, back-calculation to related hazard criteria
3. Applicability domain: applicable to classify complex metal containing materials in a Tiered approach (see EU CLP Guidance pg 499 Annex IV.5.5, and for conceptual outline ICMM Fact Sheet “Ores & Concentrates –An industry approach to EU hazard classification”, Nov 2009). Available input information: elemental composition and representative mineralogical information (lower Tier, no correction for bio availability)
4. Mechanistic interpretation - metal species:  the tool translates the elemental composition into a mineralogical composition relevant for classification (ie distribution pattern for each element/constituent of the UVCB substance). In the Lower Tier, the classification is derived (by means of the Sum formula) without taking into account any bio availability correction.   

   · Mechanistic interpretation - metal-ion additivity:  (1) The additivity assumption for the toxicity of mixtures of metals was evaluated by De Schamphelaere (2009) - in JAB Bass et al. in "Environmental Quality Standards for trace metals in the aquatic environment" , UK Environment Science Report 2009 (Appendix 2):  No clear conclusions could be made from the literature review but  a targeted experimental design with aquatic algae, showed that the additivity mode could predict the toxicity of metal mixture :  the toxicity of simultaneous Cu, Zn, Ni, Cd and Pb additions to two distinct surface waters could be predicted by the additive toxic unit approach.    (2)  A. Stockdale, E Tipping, S Lofts & SJ Ormod, combined metal speciation to the additive toxicity approach and  predicted the combined metal toxicity in a range of UK river systems impacted by metals :  in "Modelling multiple metal toxic effects in the field - evaluation of the Toxicity Binding Model (TBM)", ICA Report November 2009.  

Adequacy of prediction: the substance falls within the applicability domain described above and, therefore, the predicted value can be considered as reliable. The prediction is moreover conservative as the Lower Tier approach was used (ie elemental composition + mineralogy is known, no T/D available). Same conclusions apply to the prediction of the Aquatic toxicity value.