Concentrates of lead and zinc compounds with sulfur resulting from hydrometallurgy (hot acid leaching, super-hot acid leaching and flotation)

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

6.5 µg/L

Assessment factor:

3

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

3.4 µg/L

Assessment factor:

3

Extrapolation method:

sensitivity distribution

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

100 µg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

174 mg/kg sediment dw

Assessment factor:

3

Extrapolation method:

sensitivity distribution

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

164 mg/kg sediment dw

Assessment factor:

3

Extrapolation method:

sensitivity distribution

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

147 mg/kg soil dw

Assessment factor:

2

Extrapolation method:

sensitivity distribution

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

10.9 mg/kg food

Assessment factor:

6

Additional information

The environmental hazard assessment was conducted based on the most critical constituents of the substance. This substance is an UVCB substance and can be described as a moist solid powder which is insoluble to water. Therefore, the transformation/dissolution study (OECD guidance 29) was conducted for the substance and the results of this study were used for the chemical safety assessment.

According to T/D study results, the most soluble and critical components of this substance are lead and zinc. Therefore, the studies for this endpoint have been selected as a read-across data for the critical constituents. The read-across justification is presented in CSR annex I. All the available and reliable data on lead and zinc was taken into account for PNEC derivation. The PNEC values were derived by using the statistical extrapolation method as described in the following sections for different compartments. The PNEC values are based on the voluntary risk assessments of lead and zinc.

Ecotoxicity of lead and its compounds

In assessing the ecotoxicity of metals in the various environmental compartments (aquatic, terrestrial and sediment), it is assumed that toxicity is not controlled by the total concentration of a metal, but by the bioavailable form. For metals, this bioavailable form is generally accepted to be the free metal-ion in solution. In the absence of speciation data and as a conservative approximation, it can also be assumed that the total soluble lead pool is bioavailable. All reliable data on ecotoxicity and environmental fate and behaviour of lead and lead substances were therefore selected based on soluble Pb salts or measured (dissolved) Pb concentration.

The reliable ecotoxicity data selected for effects assessment of Pb in the various environmental compartments are derived from tests with soluble Pb salts (lead (di) nitrate, lead carbonate, lead acetate, lead chloride). Since lead is the toxic component and the anions do not contribute to toxicity, all reliable data are grouped together in a read-across approach and the PNEC’s are expressed as μg Pb/L (measured dissolved concentration) or mg Pb/kg. These results can be used for all other Pb compounds without concern on toxicity of the anions.

Ecotoxicity of zinc and its compounds

A basic assumption made in this hazard assessment and throughout this CSA, (in accordance to the same assumption made in the EU RA process) is that the ecotoxicity of zinc and zinc compounds is due to the Zn⁺⁺ion. As a consequence, all aquatic, sediment and terrestrial toxicity data in this report are expressed as “zinc”, not as the test compound as such, because ionic zinc is considered to be the causative factor for toxicity. A further consequence of this is that all ecotoxicity data obtained on different zinc compounds, are mutually relevant for each other. For that reason, the available ecotoxicity databases related to zinc and the different zinc compounds are combined before calculating the PNECs. The only way zinc compounds can differ in this respect is in their capacity to release zinc ions into (environmental) solution. That effect is checked eventually in the transformation/dissolution tests and may result in different classifications.

PNEC values for zinc

Zinc PNEC values, assessment factors and short description of derivation methods are summarised in the table below. Further explanations of the PNEC derivation are described in the CSR section 7.6.3.

Compartment	PNEC	AF	Remarks/justifications
PNEC aqua freshwater	20.6µg/l	1	Extrapolation method: statistical extrapolation. The following considerations are made on the uncertainty around the HC5 and for determining the size of the assessment factor: -The number of chronic species NOECs (23) covers more than the requirements for taxonomic groups (8) and species (at least 10, preferably more than 15) set out in the guidance. -The large number of species in the SSD resulting in a low uncertainty on the HC5 value  -The lognormal distribution giving a more conservative HC5 than the best fitting distribution (extreme values distribution) -The chronic data are from tests performed in a variety of natural freshwaters, properly reflecting the range of abiotic conditions found in the European freshwaters -The general consideration that the bioavailability of metals under real life conditions is lower than the bioavailability in laboratory toxicity tests. -The few specific NOEC values of the database that are below the HC5 can be explained by non-environmentally relevant conditions. -The inclusion of data obtained under very low background conditions into the NOEC database which introduces a significant level of conservatism into the SSD and the PNEC derivation. -Predictions from the chronic Biotic Ligand Model showing that the NOECs predicted for the realistic worst case conditions of EU waters, correspond well with the generic species mean NOEC values observed for the BLM organisms and used in the SSD. -Comparison with reliable Mesocosm data, showing no evidence that the HC5 is not protective. -Evidence on the PNEC from a large scale field survey study, demonstrating that the PNEC for zinc should be in the range 20-27µg Zn dissolved/l. The consideration of the elements above does not support the application of an additional assessment factor on the HC5 for setting the PNEC.
PNEC aqua marine	6.1µg/l	1	Extrapolation method: statistical extrapolation. The following considerations are made on the uncertainty around the HC5: -The chronic NOEC database is very extensive and contains 39 species entries that cover much more than the requirements for taxonomic groups (8) and species (at least 10, preferably more than 15) set out in the guidance; -Sensitive life stages or long chronic exposure periods (a few months) are represented in each taxonomic group as set out in the guidance; -The large number of species in the SSD results in a low uncertainty on the HC5 value, as is shown by the small difference between the 50% confidence level and the 95% confidence limits found for the lognormal distribution: less than a factor of 2.5;  -The lognormal distribution that was used for PNEC derivation resulted in an HC5 of 6.09 µg/l, which is markedly lower than the HC5 value calculated from the Weibull distribution (8.5 µg/l), which provided the best fit. So the HC5 that is used for the PNEC derivation is a conservative value; -The HC5 value from the log-normal SSD is protective for mesocosm data; -There is no indication for a particular sensitive group in the SSD. In addition, whenever an SSD includes > 20 data points, the chance of having a value below the HC5 is significant. So, having one or more values below the HC5 is inherent to bigger datasets and is not an issue as such. Based on these observations, there is no need for an assessment factor higher than 1. The PNEC saltwater for zinc is thus of 6.09 µg/L.
PNEC sediment fresh water	117.8 mg/kg dw	1	Extrapolation method: statistical extrapolation. It is emphasized that the reported PNEC for freshwater sediments is an added PNEC, i.e. natural background needs to be taken into account when characterizing the risks from monitored data. The following considerations are made on the uncertainty around the HC5 and for determining the size of AF: -The 7 available chronic single-species tests are among the most important taxonomic groups for the sediment ecosystems and as such reflect a broader difference in sensitivity among species (7.5 instead of 2.5 in the Zn RAR).     -The sediment chronic database covers long term (3 to 8 weeks) lethal and sub-lethal endpoints that are all relevant for potential effects at population level. -The lognormal distribution gives a more conservative HC5 than the best fit distribution ( logistic distribution) -The proposed PNECadd, sediment is lower than all other sediment quality guidelines/values proposed in various jurisdictions around the world (see e.g. Chapman et al. 1999, MacDonald et al. 2000) -Field data demonstrate that the proposed PNECadd, sediment is protective for ecosystems. The consideration of the elements above does not support the application of an additional assessment factor on the HC5 for setting the PNEC.
PNEC sediment marine water	56.5 mg/kg dw	1	Extrapolation method: partition coefficient It is emphasized that the reported PNEC for saltwater sediments is an added PNEC, i.e. natural background needs to be taken into account when characterizing the risks from monitored data. The following considerations are made on the uncertainty around the HC5 and for determining the size of AF:  -Lowest reported NOEC value (A. marina; emergence; 207 mg/kg d.w.) is higher than the proposed EqP PNEC    -The proposed marine EqP PNEC is lower than all other sediment quality guidelines/values proposed in various jurisdictions around the world (see e.g. Chapman et al. 1999) -The HC5 based on combined freshwater and seawater data derived from the lognormal distribution gives a value of 106 mg/kg d.w, which divided by AF2 gives a PNEC of 53 mg/kg. This value is close to the EqP PNEC -Marine sediment PNEC in the Zn RA is based on the freshwater sediment PNEC of 49 mg/kg which is in the same range -Using the AF approach gives a low PNEC value (14.6 mg/kg d.w.) which is in the lower percentiles of the natural background concentrations for zinc and is therefore not relevant
PNEC soil	35.6 mg/kg dw	1	Extrapolation method: statistical extrapolation The given value is the generic PNECadd, i.e. it has to be added to the natural background concentration of zinc. This generic PNECadd, should as a rule be multiplied with a factor 3 to take into account "lab-to-field" differences in toxicity. As such, the generic corrected PNECadd is 107 mg Zn/kg dw. Soil-specific PNEC values can further be calculated when the characteristics of the soil are documented. The following considerations are made on the uncertainty around the HC5: -The chronic NOEC database is very extensive and largely fulfils the requirements for taxonomic groups (8) and species (at least 10, preferably more than 15) set out in the guidance; -the database covers ecologically relevant endpoints and full chronic studies ; -the NOECS/EC10 were obtained by testing on soils covering the variability of soil characteristics all over the EU; - the log-normal distribution was accepted at all significance levels; - considering all individual NOEC levels, the HC5 is protective; vi) comparison with field /mesocosm studies demonstrates that the HC5 is protective. The consideration of the elements above does not support the application of an additional assessment factor on the HC5 for setting the PNEC.
PNEC STP	100 μg/l	1	Extrapolation method: assessment factor Considering that the nitrification inhibition test is most relevant of the data available, the PNEC is derived from the NOEC (100 μg Zn/l; Juliastuti et al. 2003) divided by AF 1 to give the PNEC-STP of 100μg Zn/l.No on-site relevancy for the ES&RC of the target substance.

 

PNEC derivation for the critical constituents of the target substance

PNECs for aquatic freshwater compartment

Zinc

Aquatic freshwater PNEC was calculated using statistical extrapolation method (Sensitivity Species Distribution model). All available chronic NOEC values were used as input; database consisted of NOEC values from 23 different species including fish, invertebrates, algae and aquatic plants. It is noted also that the PNEC is a PNECadd., i. e. the background concentration needs to be considered in the compliance assessment exercise.

According to R10 Guidance section R.10.3.1.3, if Assessment Factor is set below 5, a consideration regarding the database quality, statistical uncertainties and comparison with mesocosm studies needs to be made. These considerations are fulfilled (see CSR) and therefore AF was set at 1.

Sediment freshwater PNEC was calculated using statistical extrapolation method (Sensitivity Species Distribution model). All available chronic NOEC values (7 species) were used as input. It is noted also that the PNEC is a PNECadd., i. e. the background concentration needs to be considered in the compliance assessment exercise.

According to R10 Guidance section R.10.3.1.3, if Assessment Factor is set below 5, a consideration regarding the database quality, statistical uncertainties and comparison with mesocosm studies needs to be made. These considerations are fulfilled (see CSR) and therefore AF was set at 1.

Lead

The PNEC values for aquatic freshwater were derivated using statistical extrapolation method (Sensitivity Species Distribution model). PNEC was derived using geometric mean values from 17 different freshwater species.

 

According to R10 Guidance section R.10.3.1.3, if Assessment Factor is set below 5, a consideration regarding the database quality, statistical uncertainties and comparison with mesocosm studies needs to be made. Based on these considerations (see CSR), AF was set at 3.

The PNEC value for sediment freshwater was derivated using statistical extrapolation method (Sensitivity Species Distribution model). PNEC is derived using 7 EC10/NOEC values for 7 different species. According to R10 Guidance section R.10.3.1.3, if Assessment Factor is set below 5, a consideration regarding the database quality, statistical uncertainties and comparison with mesocosm studies needs to be made. Based on these considerations, AF was set at 3. Since AVS (Acid-Volatile Sulphite) is a determining factor in controlling lead toxicity in sediments, also a bioavailable PNEC (corrected for AVS) has also been derived. The result for AVS corrected PNEC value was 41 mg/kg d.w. Since some datapoints included in the SSD were derived from actual LOEC values and SCHER recommended the use of the classical AF factor approach applying a factor of 10 to the lowest unbounded bioavailable NOEC, the AF factor of 10 was chosen for the AVS corrected PNEC.

PNECs for aquatic marine compartment

 

Zinc

Aquatic marine PNEC was calculated using statistical extrapolation method (Sensitivity Species Distribution model). All available chronic NOEC values (39 geomean species NOECS) were used as input, dabase consisted from fish, invertebrates and algae. It is noted also that the PNEC is a PNECadd, i.e. the background concentration needs to be considered in the compliance assessment exercise.

According to R10 Guidance section R.10.3.1.3, if Assessment Factor is set below 5, a consideration regarding the database quality, statistical uncertainties and comparison with mesocosm studies needs to be made. These considerations are fulfilled (see CSR) and therefore AF was set at 1.

Because database for sediment marine consisted only from 2 species, sediment marine PNEC was extrapolated with Equilibrium Partitioning (EqP) method using aquatic marine water dataset (39 species). In addition, an SSD was constructed using ecotoxicity data for both freshwater and marine sediments for estimation of an HC5 using statistical extrapolation. The Assessment Factor approach was also evaluated for comparison.

It is emphasized that the reported PNEC for saltwater sediments is an added PNEC, i. e. natural background needs to be taken into account when characterizing the risks from monitored data.

Lead

 

The PNEC value for aquatic freshwater was derivated using statistical extrapolation method (Sensitivity Species Distribution model). PNEC is derived using geometric mean values from 9 different freshwater species.

 

According to R10 Guidance section R.10.3.1.3, if Assessment Factor is set below 5, a consideration regarding the database quality, statistical uncertainties and comparison with mesocosm studies needs to be made. Based on these considerations (see CSR), AF was set at 3.

 

The PNEC for marine sediments weas derived based on the use of the species sensitivity distribution approach and pooling of freshwater/marine toxicity data.High quality chronic L(E)C₁₀/NOEC values (Q1) are available for 9 different sediment-dwelling invertebrates, belonging to 3 different families (i.e. oligochaetes, crustaceans and insects) with different feeding habits and ecological niches.According to the REACH guidance if the statistical extrapolation technique is used an AF of 5 is applied unless justification can be given to apply a lower AF (between 5-1). This should bejudged on a case-by-case basis. In analogy with the rationale developed in the chapter PNEC derivation for the freshwater sediment compartment an AF of 3 is proposed.

 

PNECs for terrestrial compartment

Zinc

 

Soil PNEC was derived using statistical extrapolation method (Sensitivity Species Distribution model). All available chronic NOEC values (43 different mean NOECS) were used as input; database consisted from toxicity values for soil inverterbates, terrestrial plants and soil micro-organisms.

 

According to R10 Guidance section R.10.3.1.3, if Assessment Factor is set below 5, a consideration regarding the database quality, statistical uncertainties and comparison with mesocosm studies needs to be made. These considerations are fulfilled (see CSR) and therefore AF was set at 1.

Lead

 

The PNEC soil for lead was derived based on the use of the species sensitivity distribution approach.The ecotoxicological data are based on the data in the VRAL for Pb and Pb substances (data derived from original papers on the subject, published in international journals and research projects) and a literature update for new published relevant data since 2001. Identical reliability and relevancy criteria used as in the VRAL (LDAI, 2008).

 

When EC₁₀values are not reported in the original study, but data are available allowing derivation of a concentration-effect relationship, the EC₁₀is calculated using a logistic (sigmoidal) dose-response curve by minimising the unweighted squared residuals sum. A minimum of control and 3 test concentrations are required for derivation of a dose-response curve. If no reliable EC₁₀can be derived because e.g. no significant dose-response curve can be fitted or the EC₁₀is outside the concentration range tested, and a “real”, bounded NOEC value can be derived, this NOEC value will be used instead of the EC₁₀for PNEC derivation.

 

No unbounded NOEC or LOEC values are used for derivation of the PNEC.

 

PNECs for secondary poisoning (PNEC oral)

According to transformation/dissolution study (OECD guidance 29) conducted for the target substance, the most biovailable constituent of the target substance is lead. It is also nonessential and the most hazardous constituent in relation to the secondary poisoning. Therefore, the chemical safety assessment focuses on the toxicity of lead.

PNECoral values were derivated separately for both mammals and birds using statistical extrapolation (Sensitivity Species Distribution model). Mammal toxicity dabase consisted of 8 NOEC values from 5 species and bird toxicity database consisted of 10 studies from 2 species. A dietary Pb background concentration of 1.3 mg Pb/kgww (LDAI 2008) was added to all NOEC values before fitting the values to the SSD curve.

Assessment factor of 6 was selected, because the SSD is good estimate of the full range of the propable distribution of species sensitivities, and therefore assessment factor of 10 was considered as too cautious. As a result AF factor of 6 was chosen.

Conclusion on classification

The target substance is an inorganic solid UVCB substance which is insoluble to water. The substance consists primarily of sulphur (ca. 35 %), lead (ca. 25 %) and zinc (ca. 17 %) together with minor trace elements such as silver, silicon, aluminium, calcium and iron. Because of poor water solubility, the transformation/dissolution study (OECD guidance 29) was conducted for the substance to derive the environmental classification according to the procedure presented in the Annex IV of CLP guidance (Guidance on the application of the CLP Criteria, version 4, November 2013).

According to the T/D study, the readily soluble constituent is lead. Based on the hazard profile it is also the most hazardous constituent of this substance. Based on the mineralogical composition, lead appears in the target substance in sulphate form. The other major constituent of the target substance is zinc, and it was also bioavailable from the substance after the 28-day solubility assay with 1 mg loading (OECD guidance 29). According to the mineralogical composition, zinc appears in sulphide form in the target substance. However, the sulphur is also soluble and can appear either sulphide or sulphate form in water. Since the zinc sulphate is considered to be more bioavailable than zinc sulphide the read-across data and the self-classification of the target substance focuses on the properties of zinc sulphate and other bioavailable forms of zinc.

Bio-elution and OECD T/D transformation dissolution protocol

The metals for the T/D study analysis were selected based on the composition and the environmental hazards of the constituents in the target substance. Total concentrations of Ag, Cd, Cu, Ni, Pb, S and Zn were analysed from the eluates by means of ICP-OES. Screening tests (the 24 hour study with 100 mg loading) were performed at pH 6 and pH 8 using the OECD test media described by the protocol. The results indicated that the release at pH 6 was higher for all studied elements compared to release at pH 8. Therefore the following 7 and 28 day studies were conducted at pH 6.

The reported values are for total concentrations of elements measured in solution. In addition to measuring the pH at the stipulated sampling periods the pH was continuously measured in one of the vessels containing the target substance to monitor the behaviour of the system during exposure. The presence of the pH electrode had a strong influence on the amount of Pb in solution for the low loadings of 1 mg/L and 10 mg/L whereas no influence could be determined for the high loading of 100 mg/L. The results for all elements in the 10 mg/L and 1 mg/L tests are therefore based on two replicates. All results are corrected by subtracting the corresponding measured blank concentration.

Based on the screening test results (loading rate 100 mg/L), the most critical components for the assessment were lead and zinc, with releases of 8282 µg/L and 75.4 µg/L, respectively. The other minor leachable metals were silver (34.7 µg/L), cadmium (0.48 µg/L) and copper (17.2 µg/L). In the 28 day test with lower loading rate (1 mg/L, pH 6), only concentrations of Pb (362.4 µg/L) and Zn (3.2 µg/L) were over the detection limits or blank sample values. The 7 days tests were conducted with loading rates of 10 and 100 mg/L (see table below).

Selection of the ERV-values

Environmental reference values (ERVs) for Ag, Cu and Cd were taken from EnviChem database (see table below). The database had only few LC50 and NOEC values per element and information from the test conditions (pH, hardness, duration etc.) was often limited. Therefore the ERVs taken from database can be considered as low quality. The ERVs used in the classification were calculated as an average from the different database values.

The ERV-values for the most critical constituents (lead and zinc) were selected based on the chemical safety assessment and the read-across data presented for these most critical constituents. The ERV-values for lead have been grouped according to the toxicities measured at different pH conditions. See further information on the ERV values in the CSR section 7.6.2.

The most sensitive species and the toxicity responses for lead acute toxicity at different pH conditions:

• In the lower pH range 5.5-6.5, the lowest acute reference value is 73.6 µg/l (Ceriodaphnia dubia, LC50 48-h, pH 5.71)

• At neutral pH (7.5-8.5) the lowest acute reference value is 52 µg/l (Pimephales promelas, LC50 96-h, pH 7.4)

• At higher pH (7.5-8.5) the lowest acute reference value is 107 µg/l (Pimephales promelas, LC50 96-h, pH 8.17-8.52)

The most sensitive species and the toxicity responses for lead chronic toxicity at different pH conditions:

• In the lower pH range (5.5-6.5) the lowest chronic reference value is 17.8 µg/l (Cyprinus carpio, EC10 7-d, pH 5.6)

• At neutral pH (6.5-7.5) the lowest chronic reference value is 9.0 µg/L (Daphnia magna, EC10 21-d, pH 7.4)

• At higher pH (7.5-8.5) the lowest chronic reference value is 23.4 µg/l (Pseudokirchneriella subcapitata, EC10 48-h, pH 7.71)

As a conclusion, the lowest acute and chronic toxicity responses at neutral pH were selected as the acute ERV for lead.

• Acute ERV for Pb: 52 µg/L

• Chronic ERV for Pb: 9.0 µg/L

The most sensitive species and the toxicity responses for zinc acute and chronic toxicity at different pH conditions:

• At neutral pH (7.5) the lowest acute reference value is IC50 of 136 µg/l (72-h, Pseudokirchnerella subcapitata)

• At neutral pH (6.2-8.0) the lowest chronic reference value is NOEC of 19 µg/L (a geometric mean (n=27), 72-h, Pseudokircherniella subcapitata )

Environmental classification according to the T/D study results

Metal compounds can be classified as readily soluble, if their ERV is greater or equal to result from 24-h screening test with 100 mg loading. According to the T/D study results, lead is readily soluble (see table below).

The 24-h screening results at pH 6 with 100 mg/l).

Metal analysed from the eluate	Solubility, µg/L	ERV, µg/L	Readily soluble	Source for toxicity data
lead	8282 ± 1468	52	yes	CSA
zinc	75.4 ± 2.5	136	no	CSA
silver	34.7 ± 2.2	64.5	no	Ding et al. 1982 and Khangarot & Ray 1987
cadmium	0.48 ± 0.08	1550	no	Rachlin et al. 1982 and 1983
nickel	< 3	na	no	-
copper	17.2 ± 1.2	56.5	no	Stephenson 1983

By applying the classification instructions given in the Guidance R10 Figure IV.5.3 -a, since lead is considered as readily soluble and acute ERV is ≤ 1 mg/L, lead can be classified to the hazard class Aquatic Acute Toxicity 1 already based on the screening study results.

However, the T/D study was conducted also for 7-day and 28-day elution in order to verify the most critical constituents and their bioavailability for the overall hazard assessment and chemical safety assessment of the target substance.

The T/D study results for 7-day and 28-day at pH 6

Metal analysed from the eluate	7-d solubility, µg/L (loading rate 10 mg/L)	7-d solubility, µg/L (loading rate 100 mg/L)	Acute ERV, µg/L	28-d µg/L (loading rate 1mg/L)	Chronic ERV, µg/L
Ag	8.0 ± 7.0	31.4 ± 8.3	64.5	< 3	not relevant
Cd	< 0.5	0.056 ± 0.200	1550	< 0.5	not relevant
Cu	< 2.5	15.6 ± 2.5	56.5	< 2.5	not relevant
Pb	2122 ± 665.4	12333 ± 777	52	362.4	9.0
S	861.5 ± 19.1	3632 ± 203	not relevant	not detected	not relevant
Zn	11.3 ± 0.08	91.4 ± 4.8	136	3.2	19

Acute toxicity

Based on the screening and the 7-day T/D study results, lead is the most critical constituent triggering the target substance to be classified to acute toxicity category 1. The 7-day solubility exceeds the ERV-value of acute toxicity. In addition, since lead is considered as readily soluble and acute ERV is ≤ 1 mg/L, the target substance is classified to the hazard class Aquatic Acute 1 H400.

Since the Acute ERV value for lead is between 0.01 mg/l to 0.1 mg/l, M-factor for acute toxicity is 10.

Chronic toxicity

Based on the 28-day T/D study results, lead is the most soluble constituent. The 28-day test was conducted at 1 mg loading. In order to make conclusions of the solubility at 0.01 mg loading, the solubility value was derived by 100. The solubility at 0.01 loading after 28-d is 3.62µg/l (< Chronic ERV 9 µg/l), and not triggering the aquatic chronic category 1 classification. However, by applying the classification instructions given in the CLP Guidance in Figure IV.5.3 -b, since lead is considered as readily soluble, there is evidence of rapid environmental transformation and chronic ERV is ≤ 0.01 mg/L, lead need to be classified to hazard class Aquatic Chronic 1 H410 according the screening results.

Since there is evidence from rapid environmental transformation and the chronic ERV value for lead is between 0.001 mg/l < Chronic ERV < 0.01 mg/l, M-factor for chronic toxicity is 1.

Classification and labelling according to CLP 1272/2008:

Aquatic Acute 1 H400; M-factor = 10

Aquatic Chronic. 1 H410; M-factor = 1

Classification and labelling according to DSD 67/548/EEC:

N; R50/53