Lead Carbonate Intermediate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Good performed study according to GLP.

Justification for type of information:

Hypothesis for read-across: The main component of the target substance “Reaction product of lead chloride or lead sulphate with alkaline solution” is lead (Pb). Pb salts used as source material are waste materials produced by Pb battery recycling process or by-products of the hydrometallurgical upgrading of PGM rich lead bullion. Therefore, available data from Pb compounds was used for read-across. The test substance is waste material from lead battery reprocessing, which is similar to the target substance and therefore considered applicable for read-across.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Details on test solutions:

Because of its limited solubility the test item was applied in a water accommodated fraction (WAF) with a stirring time of 24 hours followed by a sedimentation period of 1 hour

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Tests were carried out with the green alga Desmosdesmus subspicatus CHODAT from the German Environmental Agency (Umweltbundesamt), Berlin-Marienfelde cultivated in suspension culture. The strain used for this study has been cultured in the labnoratory of Hydrotox GmbH since November 2006. Twice a week the stock suspension is diluted 2:50 into fresh Holm-Hansen medium under sterile conditions to keep it in exponential growth.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23.2 to 23.8 °C

Nominal and measured concentrations:

Nominal loading rates of 0.77, 1.73, 3.90, 8.77, 19.73, 44.40 and 99.90 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL Erlenmeyer flasks, wide necked, were sealed with a sterile cellulose stopper and incubated in a light incubator RUMED 3001
- Initial cells density: 0.8 x 10^5 algal cells/mL

OTHER TEST CONDITIONS
- Light intensity and quality: The flasks are illuminated laterally by eight fluorescent tubes (58 Watt each) which are separated from the incubation chamber by heat absorbing glass. Light intensity is continuously variable and was set on 45% of the maximum light intensity resulting in a mean light intensity of 108 uE/m2 s +/- 6.3% (PAR)

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 3.6 mg/L, 10 mg/L and a limit test of 100 mg/L
- Results used to determine the conditions for the definitive study: 3.6 mg/L inhibitions of growth rate = 30.0%, inhibition of yield = 74.7%. 10 mg/L inhibitions of growth rate = 44.3%, inhibition of yield = 87.7%. 100 mg/L resulted in an inhibition of growth rate of 93.3% and yeild of 99.5%

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

12.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

other: ErC10

Effect conc.:

3.01 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.77 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

other: EbC50

Effect conc.:

2.38 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

other: EbC10

Effect conc.:

0.36 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 0.77 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

Justification for read-across: Lead (Pb) is the main component of the target substance, and considered the major driver for adverse effects based on its properties and relative quantity in the substance. For toxicity assessment the bioavailable part is relevant. From the target substance itself, Pb is poorly water soluble. Solubility of Pb from the test substance was same order of magnitude as for the target substance. Therefore, it is considered that the used read-across data gives a good estimate on the adverse effects of the target substance.

Reported statistics and error estimates:

The NOEC and LOEC were also determined with the ToxRAT software. The specific growth rates and the yields of the treated algae compared to the controls were analysed by performing a "multiple average comparisons test" (Dunnett's test). By definition the lowest treatment concentration which is not significantly different from the control is the NOEC and the lowest treatment concentration which is significantly different from the control is the LOEC.

See IUCLID Section 13 for Analogue approach report.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Justification for read-across: Lead (Pb) is the main component of the target substance, and considered the major driver for adverse effects based on its properties and relative quantity in the substance. For toxicity assessment the bioavailable part is relevant. From the target substance itself, Pb is poorly water soluble. Solubility of Pb from the test substance was same order of magnitude as for the target substance. Therefore, it is considered that the used read-across data gives a good estimate on the adverse effects of the target substance.
See IUCLID Section 13 for Analogue approach report.

Reason / purpose for cross-reference:

read-across source

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 0.77 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.36 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.38 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.77 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

3.01 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

12.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Description of key information

For aquatic algae, four acute toxicity data points were considered for read-across purposes. Test data (1 study) was available for Pb battery reprocessing waste, which was considered to be close to the target substance based on its composition and physico-chemical properties. In addition, data was available for lead dichloride (1 study) and lead dinitrate (2 studies).

Additional information

The following lowest acute toxicity values (EC10) were reported:

Wastes, Pb battery reprocessing: 0.36 mg/L (D. subspicatus, pH and hardness not reported)

Lead dichloride: 0.005 mg/L dissolved Pb (P. subcapitata, pH 7.28, hardness 24 mg/L)

Lead dinitrate: 0.029 mg/L dissolved Pb (S. costatum, pH 8.1, hardness -)