Tin, melting residues

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

no data available: testing technically not feasible

Marine water

Hazard assessment conclusion:

no data available: testing technically not feasible

STP

Hazard assessment conclusion:

no data available: testing technically not feasible

Sediment (freshwater)

Hazard assessment conclusion:

no data available: testing technically not feasible

Sediment (marine water)

Hazard assessment conclusion:

no data available: testing technically not feasible

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no data available: testing technically not feasible

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no data available: testing technically not feasible

Additional information

The hazard assessment of inorganic UVCBs for the purpose of classification and derivation of safe effect thresholds (i.e. PNEC) is a cumbersome and complex process. Due to the intrinsic variability of the composition of an UVCB, it is difficult to select a sample that would unambiguously be representative for the (eco)toxicological hazard profile of the UVCB and could subsequently be used for testing. Instead of direct testing, a precautionary approach is taken where the UVCB is treated as a complex metal containing substance containing a number of discrete constituents (metals, metal compounds, non-metal inorganic compounds etc.). For each of these constituents, the hazard profile is used for deriving the proper classification of the UVCB (using the mixture rules) and/or for the derivation of the PNECs of the constituent (forwarded to the risk assessment). Using the PNEC of all individual constituents circumvents indirectly the issue of varying composition of an UVCB as it implicitly assumes that each time the UVCB substance consists of the pure substance, i.e. that each constituent would be present and bioavailable at a 100% concentration in the UVCB substance. This can be considered a conservative approach. A main outcome of the constituents’ based assessment is the selection of all the constituents for which any environmental hazard is identified. This selection defines the scope of the further exposure and risk assessment (CSR, Ch. 9&10).

 

The actual hazard profile of the inorganic UVCB substance and the individual constituents is dependent on the speciation of each and every constituent andhence this information needs to be collected in order to obtain a robust classification or PNEC value used for risk assessment purposes. Different scenarios can be encountered.

·      When the speciation of a constituent is known, this is used as such for the environmental hazard assessment.

·      When the speciation is unknown or few metal species co-exist, the worst-case speciation for the purpose of environmental hazard assessment is selected, i.e. the speciation that would lead to the most severe effects and thus the lowest PNEC.

 

For most metals, it is generally assumed that the Me-ion is the metal species of concern and therefore, the environmental hazard assessment is generally based on Me-ion speciation (ECHA, 2008.Guidance on information requirements and chemical safety assessment; Appendix R.7.13-2: Environmental risk assessment for metals and metal compounds)

 

Selection of the ecotoxicological information for the purpose of classification

 

The UVCB classification is calculated by applying the CLP mixture rules based on the classification of the known or worst-case speciation for each constituent and worst-case constituent concentration in the UVCB (i.e. maximum of the legal entity typical value), using the MeClas tool. Depending on the availability of information, the UVCB classification can be refined following MeClas Tiered approach.

 

Selection of the ecotoxicological information for the purpose of risk assessment

 

For the purpose of the environmental risk assessment for the UVCB, the hazards of each constituent will be assessed and PNEC values for all the constituents for which a hazard has been identified are compiled.

 

The UVCB is a complex inorganic metals containing substance. The physico-chemical characterization of the UVCB (see relevant section in IUCLID) demonstrates the presence of different metal species; intermetallic and metal sulphides which resulted in low solubilisation potential in water for most of the metals present in the UVCB.

The UVCB is an intermediate, with a very limited life cycle (manufacturing and industrial uses only).Testing the UVCB is difficult because of the large uncertainty involved when selecting representative samples due to the variable elemental concentrations in the composition of the UVCB.Derivation of PNECs for the UVCB as such are therefore difficult to interpretbecause of the uncertainty related to the representativeness of the testing. Also, exposure to the UVCB cannot be measured or modelled because of the multi-constituent character of the UVCB. For these reasons,the UVCB environmental (hazard) assessment is driven by the assessment of the individual UVCB constituents.

For the purpose of the classification, the UVCB is treated as a complex metal containing substance with a number of discrete constituting compounds (mainly metallic speciation). The hazard classifications of each metal are then factored into a combined classification of the UVCB as a whole. For environmental endpoints, additivity and/or summation algorithms are applied to quantitatively estimate the mixture’s toxicity to aquatic organisms.

For the purpose of the environmental (risk) assessment, the ecotoxicological information that was taken forward is based on all hazardous constituents of all relevant UVCBs at the site for which quantitative exposure and risk assessment was conducted. For the environment, most often, it is the metal ion that is the toxic driver (ECHA, 2008, R.7.13-2). Consequently, the PNECs expressed as metal ion are the relevant ones to forward to risk characterisation. Considering the composition of this UVCB, full solubilisation of the emissions of the various constituting speciation is metals are assessed. The physical form (powder or massive) does not lead in this case to different release potential of the elements from the UVCB and consequently no different PNECs. When quantitative exposure and risk assessment were conducted on a metal constituent, the ecotoxicological information on this individual metal is reported in the respective summary sheet. The information is taken from the respective REACH IUCLID dossiers (see annex II of this CSR). More information on the scope of the UVCB assessment can be found in the CSR of the UVCB (Chapter 9).

 

Table43:Summary of the information on ecotoxicological information for the purpose of riskassessment:

UVCB constituent			Variability in chemical composition		PNECs
Element	Speciation used for environmental risk assessment
Sn	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	Not hazardous and no PNEC available.
Cu	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	See respective PNEC summary in IUCLID and table below
Pb	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	See respective PNEC summary in IUCLID and table below
Zn	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	See respective PNEC summary in IUCLID and table below
Cd	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	See respective PNEC summary in IUCLID and table below
Ag	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	See respective PNEC summary in IUCLID and table below
Sb	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	See respective PNEC summary in IUCLID and table below
Minors: As, Ni	Metal ion	Hazard assumed as if UVCB consists of 100% worst-case speciation	See respective PNEC summary below

For the purpose of the risk assessment, the hazard conclusions and the metal-specific PNECs (Predicted No Effect Concentration) were collected for each environmental compartment. An overview of the PNECs relevant for Sn melting residues is given in the table below. PNEC for arsenic metal was not available. Consequently, one was derived based on arsenic oxide using molecular weight conversion. Elements for which no PNEC is reported inTable44have no relevant environmental hazards and for which there is no need to derive environmental threshold.

 

Table44:Overview of hazard conclusions - Predicted No Effect Concentration (PNEC) takenforward for CSA

Protection target	Unit	Sn	Cu	Pb	As
Freshwater	μg/L	No hazard identified	7.8	6.5	6.5
Marine water	μg/L	No hazard identified	5.2	3.4	0.5
Freshwater sediment	mg/kgdw	No hazard identified	87	174	64.8
Marine sediment	mg/kgdw	No hazard identified	676	164	4.5
Soil	mg/kgdw	No hazard identified	88	147	0.3
STP	μg/L	No hazard identified	230	100	30.4
Secondary poisoning	mg/kg food	No hazard identified	No hazard identified*	10.9	0.5

 

Protection target	Unit	Sb	Ag	Ni	Cd	Zn (added)
Freshwater	μg/L	113	0.04	3.55	0.19	20.6
Marine water	μg/L	11.3	0.86	8.6	1.14	6.1
Freshwater sediment	mg/kgdw	11.2	438.13	69.2	1.8	235.6
Marine sediment	mg/kgdw	2.24	438.13	69.2	0.64	113
Soil	mg/kgdw	37	0.794	29.9	0.9	107
STP	μg/L	2,550	25	330	20	52
Secondary poisoning	mg/kg	Not needed	No or insufficient available at present	12.3	0.16	No hazard identified**

*Based on the copper risk assessment, it was concluded that secondary poisoning is not relevant. The main arguments are: Copper is an essential trace element, well regulated in all living organisms. Difference in copper uptake rates are related to essential needs, varying with the species, size, life stage, seasons... Copper homeostasic mechanisms are applicable across species with specific processes being active depending on the species, life stages…. The use of BAFs are therefore not adequate. There is overwhelming evidence to show the absence of copper biomagnification across the tropic chain in the aquatic and terrestrial food chains. Field evidence has further provided evidence on the mechanisms of action of copper in the aquatic and terrestrial environment and the absence of a need for concern for secondary poisoning.

**Based on the ICDZ data on bioaccumulation of zinc in animals and on biomagnification (i.e. accumulation and transfer through the food chain), it is concluded that secondary poisoning is considered to be not relevant in the effect assessment of zinc. Major decision points for this conclusion are the following. The accumulation of zinc, an essential element, is regulated in animals of several taxonomic groups, for example in molluscs, crustaceans, fish and mammals. In mammals, one of the two target species for secondary poisoning, both the absorption of zinc from the diet and the excretion of zinc, are regulated. This allows mammals, within certain limits, to maintain their total body zinc level (whole body homeostasis) and to maintain physiologically required levels of zinc in their various tissues, both at low and high dietary zinc intakes. The results of field studies, in which relatively small differences were found in the zinc levels of small mammals from control and polluted sites, are in accordance with the homeostatic mechanism. These data indicate that the bioaccumulation potential of zinc in both herbivorous and carnivorous mammals will be low. Based on the above data, secondary poisoning and the related issues bioaccumulation and biomagnification are not further discussed in this report (Zn RAR).

 

Environmental classification justification

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 are then factored into a combined classification of the UVCB as a whole. The classification was derived using Meclas (MEtals CLASsification tool - see www.meclas.eu), a calculation tool that follows classification guidance and implementation in accordance to legal rules and technical guidance from ECHA and CLP.See IUCLID section 13 attachment for MeClas classification conclusions.

 

Table45:Summary of the information on ecotoxicological information for the purpose ofclassification

UVCB constituent		Variabiliy of elemental composition	Classification according each relevant endpoint
Element	Speciation taken forward for Tier 2 environmental classification
Sn	Elemental ion	Maximum	Self classification of the speciation, see MECLAS report in CSR Annex I
Ag	Elemental ion	Maximum	Not classified, see MECLAS report in CSR Annex I
C	Elemental ion	Maximum	Not classified, see MECLAS report in CSR Annex I
Cd	Elemental ion	Maximum	Harmonised classification of the speciation, see MECLAS report in CSR Annex I
Cu	Elemental ion	Maximum	Not classified, see MECLAS report in CSR Annex I
Fe	Elemental ion	Maximum	Not classified, see MECLAS report in CSR Annex I
Pb	Elemental ion	Maximum	Self- classification of the speciation, see MECLAS report in CSR Annex I
Sb	Elemental ion	Maximum	Not classified, see MECLAS report in CSR Annex I
Zn	Elemental ion	Maximum	Not classified, see MECLAS report in CSR Annex I
Minors: As, Ni	Elemental ion	Maximum	Below 0.1% and/or the speciation not impacting classification, see MECLAS report in CSR Annex I

* Detailed information on speciation can be found in IUCLID Section 4.23 Additional Physcio-chemical information

Conclusion on classification

The MeCLAS tool has been used to derive the classification of the UVCB.

Grade 1:

Hazard to aquatic environment (short-term): not classified

Hazard to aquatic environment (long-term): not classified

Grade 2:

Hazard to aquatic environment (short-term): not classified

Hazard to aquatic environment (long-term): Chronic Cat. 2

The estimated hazard is representative for the substance across industry, as defined by the maximum of the typical elemental concentration across industry (as outlined under IUCLID section 1.2).