Cadmium sulfoselenide

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.19 µg/L

Assessment factor:

2

Extrapolation method:

sensitivity distribution

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

1.14 µg/L

Assessment factor:

2

Extrapolation method:

sensitivity distribution

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

20 µg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

1.8 mg/kg sediment dw

Assessment factor:

1

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.64 mg/kg sediment dw

Assessment factor:

1

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.9 mg/kg soil dw

Extrapolation method:

sensitivity distribution

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

0.16 mg/kg food

Assessment factor:

10

Additional information

A basic assumption made in this hazard assessment and throughout the CSRs on cadmium and cadmium compounds, (in accordance to the same assumption made in the EU RA process), is that the causative factor for ecotoxicity of these substances is the Cd⁺⁺ion. As a consequence, for the setting of PNEC's for these substances, the generic PNEC as derived for the Cd⁺⁺ ion is used, and is always referring to the Cd ion concentration.

However, Cd-substances can differ significantly in their solubility, i.e. their capacity to release cadmium ions into (environmental) solution. That effect is checked eventually in the transformation/dissolution tests and may result in different environmental hazard and, consequently, different classification for aquatic effect.

The detailed deriviation of the PNEC's for the Cd-ion for the several environmental compartments can be found back in CSR for e.g. Cd metal (November 2010). Hereunder, a brief summary of the derivation of the different PNEC values is given:

In the EU RA, it was concluded that the conditions for using a statistical extrapolation method to derive the PNEC for Cd in freshwater were met. Accordingly, this approach is also used for the present analysis. All chronic data mentioned in table below are used in a species sensitivity distribution (SSD), and the PNEC is derived based on the HC5 concentration.

The HC5 calculated out of this SSD is 0.38 µg Cd/l. according to the EU risk assessment, an AF of 2 was used. This leads to a PNEC of 0.19 µg Cd/L.

organism	medium	H	endpoint	NOEC (µg/L)	reference
Salmo gairdneri	aerated well water; T 10; O27.5; pH 8-8.6	375-390	mortality	12	Lowe-Jinde and Niimi, 1984
Salmo gairdneri no geometric mean calculation: different test medium	synthetic water (ISO 1977); T 25; pH 8.3	100	median survival time	4   (no geomean)	Dave et al., 1981
Oncorhynchus kisutch	sand filtered Lake Superior Water; continuous flow; DO 10.3; Al 41; Ac 3; pH 7.6	45	biomass	1.3	Eaton et al., 1978
Salvelinus fontinalis	sand filtered Lake Superior Water; continuous flow; DO 10.3; Al 41; Ac 3; pH 7.6	45	biomass	1.1	Eaton et al., 1978
Salvelinus fontinalisgeometric mean calculation: same test medium, same endpoint (biomass)	sterilised Lake Superior water; pH 7-8; Al 38-46; Ac 1-10; DO 4-12; T 9-15	42-47	total weight of young /female of the 2nd generation	0.9 geomean =1.0	Benoit et al, 1976
Salvelinus fontinalis	reconstituted soft water: T 14-; DO 9.3-11.4 mg/L; Cd(BG) <0.2 µg/L; pH 6.3-7.6; H 20	20	survival	8	Jop et al., 1995
Salvelinus fontinalisgeometric mean calculation: similar test medium, same endpoint (survival)	river water: T 14-; DO 8.7-12.2 mg/L; Cd(BG) <4 µg/L; pH 6.6-7.4; H 16-28	16-28	survival	62 geomean =22	Jop et al., 1995
Salmo salar	municipal water charcoal filtered and UV sterilised; BC 0.13 µg Cd/L; pH 6.5-7.3; T 5-10; DO 11.1-12.5; Al 14-17	19-28	total biomass	0.47	Rombough and Garside, 1982
Catostomus commersoni Esox lucius Salvelinus namaycush Salmo trutta (late eyed eggs)	sand filtered Lake Superior Water; continuous flow; DO 10.3; Al 41; Ac 3; pH 7.6	45	standing crop (biomass) biomass	4.2 4.2 4.4 1.1	Eaton et al., 1978
Jordanella floridae	untreatedwater; T 25; DO 8.3; Al 42; Ac 2.4; pH 7.1-7.8	44	reproduction	4.1	Spehar, 1976
Brachydanio rerio	synthetic water (changed ISO); T 24; DO >80%; pH 7.2	100	reproduction	1	Bresch., 1982
Oryzias latipes no geometric mean calculation: different test medium	tap water; continuous flow; T 20	200 100	mortality and abn. behaviour	6 3	Canton and Slooff, 1982
Xenopus laevis	tap water; continuous flow; T 20	170	inhibition of larvae development	9	Canton and Slooff, 1982
Pimephaless promelasgeometric mean calculation: same test medium, same endpoint (reproduction)	pond water diluted with carbon filtered demineralised tap water; DO 6.5-6.6; pH 7.6-7.7; Al 145-161; Ac 8-12; T 16-27	201-204	reproduction (pond fish) reproduction (laboratory fry)	13   14geomean =13.5	Pickering and Gast, 1972
Daphnia magna	50 µm filtered and sterilisedwater; pH 8.1; T 20; H 224	224	intrinsic rate of natural increase	3.2	Van Leeuwen et al., 1985
Daphnia magna no geometric mean calculation: different endpoints	NPR synthetic water; pH 8.4; T 20	200	mortality	1	Van Leeuwen et al., 1985
Daphnia magna different medium	synthetic water; T 25; pH 8; DO 69%	11	reproduction	0.6	Kühn et al., 1989
Daphnia magna	Synthetic water; Al 65; T 25	90	reproduction	2	Winner, 1988
D. magna: geometric mean calculation: similar medium, same endpoint)	well water: T 20±2°C; DO 4.9-7.9; Cd(BG) 0.08; pH 7.9	103	reproduction	0.16geomean =0.6	Chapman et al., 1980
	well water: T 20±2°C; DO 4.9-7.9; Cd(BG) 0.08; pH 8.2	209	reproduction	0.21	Chapman et al., 1980t
Daphnia magna	unchlorinated, carbon filtered well water, aerated to saturation; Al 230; pH 8; DO >5; T 23; Cd < 0.01 µg Cd/L	240	reproductive impairment	2.5	Elnabarawy et al., 1986
Daphnia magna no geometric mean calculation: different medium	aerated well water; DO >70%; pH 8; T 22; Al 250	300	reproduction	0.8	Knowles and McKee, 1987
Daphnia magna	culture medium; pH8.4; T 20	150	biomass production/female	2.5	Bodar et al., 1988a
Daphnia magna no geometric mean calculation: different medium	20 µm cloth filteredwater; pH 7.7; Al 42.3; DO 9; T 18	45.3	weight/animal	1	Biesinger and Christensen, 1972
Daphnia pulex	Whatman N° 1 filteredwater; pH 7.7; Al 42.4; Cd < 1µg L^-1	65	longevity	1	Bertram and Hart, 1979
Daphnia pulex	unchlorinated, carbon filtered well water, aerated to saturation; Al 230; pH 8; DO >5; T 23; Cd < 0.01 µg Cd/L	240	reproductive impairment	7.5	Elnabarawy et al., 1986
Aplexa hypnorum: immature	Lake Superiorwater; DO 7.5; T 24		growth	4.41	Holcombe et al., 1984
Physa integra	untreated Lake Superior water; pH 7.1-7.7; T 15; DO 10-11; Al 40-44; Ac 1.9-3	44-48	mortality	8.3	Spehar et al., 1978
Daphnia galeata mendotae	10 µm filtered Lake Michigan water; T 18.5	120	number of individuals	2	Marshall, 1978
Ceriodaphnia reticulata	unfiltered river water; static; Ac 2-4.2; Al 41-65; pH 7.2-7.8	55-79	reproduction	3.4	Spehar and Carlson, 1984
Ceriodaphnia reticulata no geometric mean calculation: different medium	unchlorinated, carbon filtered well water, aerated to saturation; Al 230; pH 8; DO >5; T 23; Cd < 0.01 µg/L	240	reproductive impairment	0.25	Elnabarawy et al., 1986
Ceriodaphnia dubia  no geometric mean calculation: different medium, different endpoint	Synthetic water; Al 65; T 25	90	mortality	1.5	Winner, 1988
Ceriodaphnia dubia	reconstituted soft water: T 14-; DO 9.3-11.4 mg/L; Cd(BG) <0.2 µg/L; pH 6.3-7.6; H 20	20	reproduction	10	Jop et al., 1995
Ceriodaphnia dubiageometric mean calculation: similar medium, same endpoint (reproduction)	river water: T 14-; DO 8.7-12.2 mg/L; Cd(BG) <4 µg/L; pH 6.6-7.4; H 16-28	16-28	reproduction	11geomean =10.5	Jop et al., 1995
Hyalella azteca	well water: T 23; pH 7.8	280	Survival	0.51	Ingersoll and Kemble, 2000
Chironomus tentans	well water: T 23; pH 7.8	280	weight	5.8	Ingersoll and Kemble, 2000
Selenastrum capricornutum	modified ISO 6341 medium; 0.2 µm filtered; T 20.3-25.6; pH 7.7-10.4	49	cell number	2.4	LISEC, 1998a
Coelastrum proboscideum	AM; T 31; pH 5.3;	32	biomass	6.3	Müller and Payer 1979
Asterionella formosa	AM; pH 8	121	growth rate	0.85	Conway and Williams 1979
Chlamydomonas reinhardii	AM; pH 6.7; T 20	42	steady state cell number	7.5	Lawrence et al. 1989
Scenedesmus quadricauda	AM; pH 7		biomass (OD)	31	Bringmann and Kühn, 1980
Lemna paucicostata no geometric mean calculation: different medium	AM; T 25 pH>6 pH 5.1 pH 5.1	120 120 700	number of fronds	5 10 10	Nasu and Kugimoto, 1981

T = temperature (°C); H = hardness (as mg CaCO₃/L); DO = dissolved oxygen (mg O₂/L); Al = alkalinity (mg CaCO₃/L); Ac = acidity (mg CaCO₃/L); AM, artificial medium.

 

The marine cadmium database largely fulfils the species and taxonomic requirements for input chronic toxicity data as explained in the RIP R. 10 guidance (at least 10 species NOECs and 8 taxonomic groups). Indeed, 48 species mean NOECs based on 62 NOEC values, coming from 39 families and from 9 taxonomic groups covering three trophic levels were found to fulfil the relevancy and reliability requirements as explained by Klimisch et al. 1997. The marine Cd database includes 1 micro- and 1 macro-algae species, 4 annelid species, 11 crustacean species, 7 echinoderm species, 13 mollusc species, 3 nematod species, 2 cnidarian species, 1 ascidian species and 6 fish species.

Following endpoints were selected for the use in SSD for the derivation of marine PNEC for Cd.

 

Cadmium aquatic marine database (chronic toxicity data)
Taxonomic group	Species name	Family	Geomean NOECaddvalue (µg Cddiss/L)	Reliability
Micro-Algae (1)	-         Chaetoceros compressum	Chaetocerotacae	18.3	2
Macro-Algae (1)	-         Ulva pertusa	Ulvaceae	63	2
Annelids (4)	Capitella capitata Ctenodrilus serratus Neanthes arenaceadontata Ophryotrocha diadema	Capitellidae Ctenodrilidae Nereididae Dorvilleidae	126.5 320.9 126.5 100	2 2 2 2
Cnidarians (2)	Eirene viridula Campanularia flexuosa	Eirenidae Campanulariidae	100 87.7	2 2
Crustaceans (11)	Artemia franciscana Artemia parthenogenetica Artemia persimilis Artemia salina Balanus Amphitrite Elminius modestus Mysidopsis bahia Paragraspus quadridentatus Penaeus monodon Tigriopus brevicornis Moina monogolica	Artemiidae Artemiidae Artemiidae Artemiidae Balanidae Archaeobalanidae Mysidae Grapsidae Penaeidae Harpacticidae Moiniidae	39.3 106.1 99.5 56.7 5 316 2.2 105 33.3 36.7 1.8	2 2 2 2 2 2 2 2 2 2 1
Echinoderms (7)	Arbacia lixula Asterias amurensis Echinometra mathaei Lytechinus pictus Paracentrotus lividus Sphaerechinus granularis Strongylocentrotus droebachiensis	Arbaciidae Asteriidae Echinometridae Toxopneustidae Echinidae Toxopneustidae Strongylocentrotidae	357 10000 10 4.2 35.5 623 12.5	2 2 2 2 2 2 2
Molluscs (13)	Crassostrea cucullata Crassostrea gigas Crassostrea margaritacea Haliotis rubra Ilyanassa obsolete Isognomon californicum Meretrix lusoria Mya arenaria Mytilus edulis Mytilus galloprovincialis Perna viridis Ruditapes decussatus Tresus nuttalli	Ostreidae Ostreidae Ostreidae Haliotidae Nassariidae Isognomonidae Veneridae Myidae Mytilidae Mytilidae Mytilidae Veneridae Mactridae	7.1 13 12.6 520 112.4 0.3 33.3 50 480 119.8 345.8 265 42	2 2 2 2 2 2 2 2 2 2 and 1 2 and 1 2 2
Nematods (3)	Monhystera disjuncta Monhysteramicrophthalma Pellioditis marina	Monhysteridae Monhysteridae Rhabditidae	3333 1000 25000	2 2 2
Ascidians (1)	Ciona intestinalis	Ascidiaceae	430.5	1 and 2
Fish (6)	Atherinops affinis Epinephelus coioides Lates calcarifer Menidia menidia Mugil cephalus Pseudopleuronectes americanus	Atherinidae Serranidae Centropomidae Atherinidae Mugilidae Pleuronectidae	10 33.3 794 259.8 20 283.7	1 2 2 2 2 2
TOTAL: 10 Tax. gps	48 species	39 families	48 species mean NOECs

The 5^thpercentile value of the SSD (the HC5), set at 50% confidence value, using the lognormal distribution (ETX 2.0) function, results in a value of 2.28 µg Cd/L.This value is taken forward for the PNEC derivation. Using an AF of 2 leads to a PNEC of 1.14 µg Cd/L.

The assessment of the freshwaterPNEC_sediment for cadmium identified only two long-term ecotoxicity studies from the scientific literature. However, both the “Added” EqP (using partitioning coefficients and a robust aquatic toxicity database from the Cd RAR) and AF (using the lowest NOEC from a field colonization study) approaches produced consistent derivations for the freshwater benthic compartment. The resulting value is considered protective for EU freshwater ecosystems: freshwater PNEC_{add, sediment}of 1.80 mg/kg d. w. (equivalent to 0.40 mg/kg w. w.). It is emphasized that this is an added PNEC, i. e. natural background needs to be taken into account when characterising the risk from monitored data.

The assessment of the marine PNEC_sediment for cadmium identified only two long-term ecotoxicity studies from the scientific literature. However, an “Added” EqP (using partitioning coefficients and a robust aquatic toxicity database) approach provided a reliable derivation for the marine benthic compartment. The resulting value is considered protective for EU marine ecosystems: marine PNEC_{sediment, added}of 0.64 mg/kg d. w. (equivalent to 0.14 mg/kg w. w.). It is emphasised that this is an added PNEC, i. e. natural Bg needs to be taken into account when characterising the risk from monitored data.

The PNEC soil is set based on the lowest observed HC5 derived by statistical extrapolation from the microflora data, i. e.2.3 µg Cd/kg d. w. In the Cd RA, an AF 1 or 2 was considered. The current analysis rather suggests using an AF 1 on the HC5 to derive the PNEC. It is noted that the PNEC_soilbased on secondary poisoning is 0.9 µg Cd/g dwwhich is below the proposed value. The latter value is therefore proposed and used for PNECsoil in this assessment. This is in accordance with the approach followed in the Cd RA (ECB 2007).

The EU risk assessment discussed available data for Cd toxicity to micro-organisms.There were 2 high quality studies available, both performed according to OECD protocol (OECD 209) for testing effect on sludge respiration, showing similar NOEC values when Cd was expressed as the dissolved fraction. The LOEC values observed on the dissolved Cd fraction were high as compared to LOEC values for aquatic species. This suggested low sensitivity of bacteria to Cd was confirmed by results on bacterial cultures of Pseudomonas putida, Zoogloea ramigera and Escherichia coli, which also showed LOECs in the 1mg/l range (RA Cd/Cd0 table 3.2.32.) / The PNEC for STP was derived in the EU risk assessment by applying an assessment factor of 10 on the lowest observed NOEC (200 µg Cd/l) which yielded a PNEC_STPof 20 µg Cd/l. The same PNEC is used for the present exercise.

The EU risk assessment on cadmium identified 4 good quality feeding studies on birds and 5 studies on mammals. According to the RA, the PNEC oral secondary poisoning is derived from the lowest NOEC on Mallard ducks (1.6 mg Cd/kg diet; White et al 1978).The PNEC oral can be calculated applying an assessment factor of 10 on this long-term feeding study,i. e. 0.16mg Cd/kg diet.

Conclusion on classification

CdSSe is specifically excempted from classification under DSD 67/548/EEC. The reason for this non-classification is the insolubility of the substance.

For CLP, data were generated to check this existing classification against the CLP rules. To this end, transformation/dissolution (T/D) tests were performed on the CdSSe, and reference was made towards newly generated T/D and ecotoxicity data obtained on another sparingly soluble Cd-compound, i.e. CdTe. By comparing T/D data between CdSSe and CdTe, and referring to aquatic effect levels observed for CdTe, the aquatic hazard of the CdSSe could be assessed as follows:

Acute aquatic classification

Standard ecotoxicity testing on CdTe revealed a lowest EC50 value of 1.14 mg CdTe/L observed for Daphnia magna (resulting in no acute classification of CdTe). T/D testing on CdTe demonstrated the sparingly soluble character of this substance (3.2% of Cd solubilised after 7days in pH 6 medium, which is maximising Cd-solubilisation in the relevant pH range 6 -8.5). The solubility of Cd from CdSSe was however even much lower than the solubility of Cd in CdTe: after 7 days only 0.026 % of the Cd was solubilised from CdSSe at pH 6. Considering a) the lowest EC50 value of CdTe of 1.14mg/l, and b) the >100x lower solubility of Cd in CdSSe, as compared to CdTe, it is concluded that also CdSSe is not classified for acute aquatic effect.

Chronic aquatic classification

Standard ecotoxicity testing on CdTe revealed a lowest NOEC value of 0.2 mg CdTe/L observed for Daphnia magna,resulting in classification as

"chronic 3" of CdTe - in this respect it is noted that Cadmium compounds are considered as being "equivalent to rapidly degradable" based on their rapid removal from the water column, see section 4.6.). T/D testing on CdTe demonstrated the sparingly soluble character of this substance (3.8% of Cd solubilised after 28 days in pH 6 medium, which is maximising Cd-solubilisation in the relevant pH range 6 -8.5). From T/D tests, it was shown that the solubility of Cd from CdSSe was however even much lower than the solubility of Cd in CdTe: after 28 days only 0.028 % of the Cd was solubilised from CdSSe at pH 6. Considering a) the lowest NOEC value of CdTe of 0.2mg/l, and b) the >100x lower solubility of Cd in CdSSe, as compared to CdTe, it is concluded that CdSSe is not classified for chronic aquatic effect.

This analysis confirms the non-classification of CdSSe for aquatic effects under DSD.