Lithium chloride

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

Study period:

2010-09-20 to 2010-10-22

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

2006

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

At the start of the experiment five parallel samples were taken from each concentration level and from the control. At the end two samples were taken from each replicate test vessel and from the control. Representative samples (in duplicate series) were taken at the start and at the end of the experiment. One series are stored frozen (ca. -20 degree C) in the testing laboratory, one series was sent for analysis, and was analysed immediately after sampling. The analysis was performed according to the results of the validated analytical method (Ion Selective Electrode (ISE) based on potentiometry).

Vehicle:

no

Details on test solutions:

A solution of the test item with a concentration of 160 mg/L in Algal Mineral Salts Test Medium (“OECD Medium”) was prepared just before the main experiment by mechanical dispersion. The Algal Mineral Salts Test Medium (according to OECD 201) was prepared by adding the appropriate volumes of following stock solutions to deionised water.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Source: SAG: Collection of Algal Cultures, Inst. Plant Physiology, University of Göttingen, Nikolausberger Weg 18, D-37073 Göttingen, GERMANY
- Method of cultivation: The stock cultures are small algal cultures that are planted on agar regularly. These are transferred to fresh medium at least once every two months under standardized conditions according to the test guidelines. The pre-culture is intended to give an amount of algae suitable for the inoculation of test cultures. The pre-culture was prepared with Algal Mineral Salts Culture Medium, incubated under the conditions of the test and used when still exponentially growing, normally after an incubation period of about three days. The pre-cultured algal cultures were healthy and did not contain deformed or abnormal cells.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

Determination of Cell Number
The cell number was determined at 24, 48 and 72 hours after starting the test by manual cell counting using a microscope with a counting chamber.
The cell morphology was examined in parallel.

Behavior of the Test Item
The behavior of the test item in test medium was determined daily (at the cell counting) in all test concentrations.

Test temperature:

The cultures were maintained at a temperature in the range of 21 – 24 degree C controlled at +/- 2 degree C, which was checked at the beginning of the study and every 24 hours in a flask filled with water. In addition, the temperature was continuously measured (with a min/max thermometer) within the climate chamber.

pH:

The pH of the stock solution was adjusted to the pH of the Algal Mineral Salts Test Medium (to ca. 7.83) using 1N HCl at the start of the test. The pH should normally not vary by more than 1.5 units in any one test. However, due to the test item character, the pH variation in this test at the concentrations of 0, 5, and 20 mg/L was more than 1.5 units during adjustment.

Nominal and measured concentrations:

The nominal test item concentrations were 5; 10; 20; 40; 80 and 160 mg test item/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks of 250 mL volume with 100 mL test medium
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: Yes
- Light intensity and quality: 8000 lux (in average of 8015 lux)

Equipment:
Normal laboratory equipment and the following were necessary for determination of the parameters of the test:
- balance
- pH meter
- thermometer
- light-meter
- laboratory orbital shaker
- microscope with counting chamber
- climate chamber

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

41.62 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

biomass

Remarks on result:

other: 95% CL: 36.78 - 47.09

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

153.44 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

growth rate

Remarks on result:

other: 95% CL: 120.05 - 196.12

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

other: biomass and growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

other: biomass and growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

23.75 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for LiOH anhydrous based molecular weights

Basis for effect:

biomass

Remarks on result:

other: 24.06 mg/L based on the LiOH content of 57.8%

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

87.57 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for LiOH anhydrous based molecular weights

Basis for effect:

growth rate

Remarks on result:

other: 88.69 mg/L based on the LiOH content of 57.8%

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

5.71 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for LiOH anhydrous based molecular weights

Basis for effect:

other: biomass and growth rate

Remarks on result:

other: 5.78 mg/L based on the LiOH content of 57.8%

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

11.41 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for LiOH anhydrous based molecular weights

Basis for effect:

other: biomass and growth rate

Remarks on result:

other: 11.56 mg/L based on the LiOH content of 57.8%

Details on results:

Analytical Results:
At the start and at the end of the test the four highest (nominal) concentrations, 20, 40, 80 and 160 mg/L were above the quantification limit (the limit of quantification of the analytical method was 0.5 mmol Li+/L, equivalent to 20 mg lithium hydroxide monohydrate /L) of the analytical method, and these measured test item concentrations were 96-102 % of the nominal at the start and 94-101 % of the nominal at the end of the test. The concentrations of 5 and 10 mg/L were out of the measurable range.
There is evidence that the concentrations of the tested substance (20-160 mg/L) were satisfactorily maintained within ± 20 % of the nominal concentrations throughout the test. The two lowest not analysed concentration levels were considered as being within the ± 20 % of the nominal range; therefore the analysis of the results was based on the nominal concentration values. All reported biological results are related to the nominal concentrations of the test item.

Biological Results:
The test item had a statistically significant inhibitory effect on the growth based on the average specific growth rate, yield and areas under the growth curves of Pseudokirchneriella subcapitata after the exposure period of 72 hours in the concentration range of 20–160 mg test item/L. The test concentration of 20 mg/L was determined as the 72-hour LOEC.

Microscopic Examinations:
Shape of the Algal Cells: The shape of the algal cells growing was obviously not affected.
Cell Density in Control: In the control the cell density has increased from nominal N= 1 x 10E4 cells/mL at the start of the test (0 hours) to N= 82.67 x 10E4 cells/mL (mean value) after 72 hours by a factor of 82.67. Thus, the algal growth in the control was high enough to pass the validity criteria in this assay.


pH-Values: pH 7.80 to 7.83 at test start; pH 8.08 to 9.92 at test end
Temperature in the test media: 22.8 - 23.1 degree C
Behaviour of the Test Item: There were no remarkable observations

Results with reference substance (positive control):

Reference Standard
For the evaluation of the quality of the algae and the experimental conditions potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.
The ErC50 value of potassium dichromate of the last study is: 1.05 mg/L (95 % confidence limits: 0.96 - 1.16 mg/L).
The growth rate, 72h value is in accordance with the accepted 1.10 ± 0.48 mg/L range for Pseudokirchneriella subcapitata.

Reported statistics and error estimates:

Statistical analysis:
Mean values and standard deviations were calculated for each treatment at the start, and at the end of the test using Excel for Windows software. Percentage inhibition of area (A), yield (Y) and growth rate (r) were calculated using EXCEL for Windows software. The EC50 values of the test item and their confidence limits were calculated using Probit analysis. The analysis was done using the TOXSTAT statistical software program. For the determination of the LOEC and NOEC, the calculated mean biomass b (area under the growth curve), growth rates r and yield at the test concentrations were tested on significant differences to the control values by Dunnett’s Test (at the 24-hour average specific growth rates and areas under the growth curves), Bonferroni t-Test and Williams’test by TOXSTAT software. The data were checked for normality by Chi-Square Test, for homogeneity of variance by Levene’s Test.

Influence of lithium hydroxide monohydrate on the growth of Pseudokirchneriella subcapitata:

Parameter (0-72 h)	Calculation based on
	Biomass b	Growth rate r
	[mg/L]	[mg/L]
EC 50	41.62	153.44
95 % conf. limits	36.78 - 47.09	120.05 - 196.12
NOEC	10	10
LOEC	20	20

Validity criteria fulfilled:

yes

Conclusions:

Lithium hydroxide monohydrate was tested for toxicity to algae in a 72 h static test according to EU Guideline C.3 and OECD Guideline 201. The results showed an EC50 value of 41.62 mg/L based on biomass and 153.44 mg/L based on growth rate (equivalent to 23.75 mg/L resp. 87.57 mg/L referred to lithium hydroxide anhydrous). The NOEC based on growth rate for lithium hydroxide monohydrate was 10 mg/L. The NOEC calculated for lithium hydroxide anhydrous was 5.71 mg/L.

Executive summary:

The influence of the test item lithium hydroxide monohydrate on the growth of Pseudokirchneriella subcapitata was investigated in a 72 h static test according to EU method C.3 and OECD Guideline No. 201. The test item had a statistically significant inhibitory effect on the growth based on the average specific growth rate, yield and areas under the curves of Pseudokirchneriella subcapitata after the exposure period of 72 hours in the concentration range of 20 - 160 mg/L test item/L (Bonferroni t-Test, alpha=0.05). The test concentration of 20 mg/L was determined as the 72-hour LOEC. The results showed an EC50 value of 41.62 mg/L based on biomass and 153.44 mg/L based on growth rate (equivalent to 23.75 mg/L resp. 87.57 mg/L referred to lithium hydroxide anhydrous). The NOEC based on growth rate for lithium hydroxide monohydrate was 10 mg/L. The NOEC calculated for lithium hydroxide anhydrous was 5.71 mg/L.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2010-04-30 to 2010-07-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

In order to confirm correct dosage and stability of exposure concentration samples (about 50 mL) of the control and all test concentrations were taken from separate vessels including culture medium (controls), test solutions and algae at 0 h and 72 h. In order to remove the algae from the test solutions, AES-analysis was performed after centrifugation of the samples at 3950 rpm for 10 minutes, followed by dilution of the samples in deionised water to meet the linear range of the calibration lines.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test Item in culture medium for the range-finding test and from a stock solution of 400 mg/L of the test item in culture medium for the definitive test, respectively. The stock solutions and the corresponding dilutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes). The test solutions were clear at all test concentrations. The range-finding test and the definitive test were performed as static tests, i.e., without renewal of the test solutions. The controls were kept in culture-medium. Vessels including culture-medium (controls) and test solutions were kept under the same conditions as the test vessels for concentration analysis. Concentration-analysis was performed at 0 h and 72 h. The Alga-test was carried without adjustment of the pH.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Desmodesmus subspicatus (Chlorophyceae, Chlorococcales),
- Strain: SAG 86.81
- Source (laboratory, culture collection): Albrecht von Haller Institut für Pflanzenwissenschaften der Universität Göttingen
- Method of cultivation: Sterile on agar tubes (0.8 % Agar). Transferred to a new agar tube every 2 months.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24.2 to 24.7 °C

pH:

in the flasks at 0 h:
8.0 to 10.9

in the flasks at 72 h:
9.6 to 10.6

The test item had a significant effect on the pH of the test solutions at the start of the exposure period.

Nominal and measured concentrations:

Nominal test concentrations: Control, 25.0 mg/L, 50.0 mg/L, 100 mg/L, 200 mg/L, 400 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL Erlenmeyer flasks (test volume 100 mL)
- Aeration: none
- Initial cells concentration: 5000 cells/mL
- No. of vessels per test group (replicates): 3
- No. of vessels per control group (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 400 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Li2CO3

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

90 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Li2CO3

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Li2CO3

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Li2CO3

Basis for effect:

growth rate

Details on results:

The test item had a significant effect on the pH of the test solutions at the start of the exposure period. The increase of pH in the control and test concentration of 25.0 mg/L during the exposure period is caused by the growth of the algae in the test vessels. In common with other species of fresh-water algae, Desmodesmus subspicatus gains CO2 from HCO3-, leading to a release of hydroxide ions, that raised the pH of the medium. After 72 hours, the pH at test concentration of 100 mg/L had remained stable, a slight decrease of the pH was observed at test concentrations of 50, 200 and 400 mg/L when compared to the 0 hour measurements. In the test the increase of pH in the control of 2.6 (> 1.5 units as recommended in OECD-Guideline 201) had no effect on the growth of the algae as the validity criteria for algal growth were fulfilled.

Reported statistics and error estimates:

The Kolmogorov-Smirnov-test determined normality of the data (α = 0.05). The results of a one-way ANOVA showed a significant effect on the specific growth rate [µ] in the presence of lithium carbonate (F = 66.04; F critical = 5, 12, α = 0.05 = 3.11). Bartlett`s test detected homogeneity of variances (α = 0.05). Dunnett`s test for comparison of the treatment groups with the control showed significant differences between the control and the effective concentrations of 100, 200 and 400 mg/L (α = 0.05).

Concentration of the test item, cells/mL in the test flasks at 72 h, average specific growth rate [µ]over the whole testing period 0-72 h, mean value of the average specific growth rate [µ], standard deviation and coefficient of variation Vc[%], inhibition [%] and mean value of inhibition [%] of the average specific growth rate [µ] in the definitive test:

Concentration [mg/L]	Cells / mL	Average Specific growth rate [µ]	Average Specific growth rate [µ] Mean value	Standard deviation	Coefficient of variation Vc [%]	Inhibition of Average Specific growth rate [%]	Inhibition of Average Specific growth rate Mean value [%]
	72 h	0-72 h	0-72 h	0-72 h	0-72 h	0-72 h	0-72 h
Control 1	720000	1.66	1.66	0.01	0.90
Control 2	752000	1.67
Control 3	688000	1.64
25.0	752000	1.67	1.68	0.01	0.82	-0.89	-1.37 *
25.0	808000	1.70				-2.33
25.0	752000	1.67				-0.89
50.0	512000	1.54	1.57	0.08	5.02	6.85	5.15
50.0	728000	1.66				-0.24
50.0	464000	1.51				8.83
100	312000	1.38	1.44	0.06	3.93	16.8	13.0 **
100	432000	1.49				10.3
100	400000	1.46				11.8
200	320000	1.39	1.33	0.06	4.49	16.3	20.0 **
200	224000	1.27				23.5
200	264000	1.32				20.2
400	136000	1.10	1.09	0.02	2.22	33.5	34.4 **
400	136000	1.10				33.5
400	120000	1.06				36.0

* Remark: A negative inhibition value means an enhancement of the parameter.

** Significant difference compared to the control according to Dunnett`s test (p = 0.05).

Validity criteria fulfilled:

yes

Conclusions:

In this 72-h algal growth inhibition test with Desmodesmus subspicatus the 72-h EC50 of lithium carbonate based on growth rate was determined as greater than 400 mg/L. The overall NOEC was determined to be 50 mg/L. The results are based on the nominal concentrations.

Executive summary:

The effect of lithium carbonate on the growth of an algal species Desmodesmus subspicatus over a 72-hour static exposure period was assessed according to OECD guideline 201. The test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test item in culture medium for the range-finding test and from a stock solution of 400 mg/L of the test item in culture medium for the definitive test, respectively. The stock solutions and the corresponding dilutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes). The test solutions were clear at all test concentrations. The controls were kept in culture medium. Vessels including culture medium (controls) and test solutions were kept under the same conditions as the test vessels for concentration analysis. Concentration analysis was performed at 0 h and 72 h. The Alga-test was carried without adjustment of the pH.AES-analysis confirmed that the test solutions were correctly dosed, i.e., the recoveries were within 92.4 to 103 % of the nominal concentrations at study start. At the end of the exposure, i.e., after 72 hours, the recoveries ranged from 95.9 to 103 % of the nominal concentrations demonstrating that the lithium concentrations were stable throughout the exposure period. Consequently, the results of the definitive test were based on nominal concentrations.In this 72-h algal growth inhibition test with Desmodesmus subspicatus the 72-h EC50 based on growth rate was determined as greater than 400 mg/L for lithium carbonate.

The overall NOEC was determined to be 50 mg/L for lithium carbonate (the calculated NOEC for lithium ion: 9.39 mg/L) . The results are based on the nominal concentrations.

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2010-04-30 to 2010-07-13

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

In order to confirm correct dosage and stability of exposure concentrations samples (about 50 mL) of the control and all test concentrations were taken from separate vessels including culture-medium (controls), test solutions and algae at 0 h and 72 h. In order to remove the algae from the test solutions, AES-analysis was performed after centrifugation of the samples at 3950 rpm for 10 minutes, followed by dilution of the samples in deionised water to meet the linear range of the calibration lines.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
The test solutions were prepared in a dilution series from a stock solution of
100 mg/L of the Test Item in culture-medium for the Range-Finding Test and from a stock solution of 400 mg/L of the Test Item in culture-medium for the Definitive Test, respectively. The stock solutions and the corresponding dilutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes). The test solutions were clear at all test concentrations. The Range-Finding Test and the Definitive Test were performed as static tests, i.e., without renewal of the test solutions. The controls were kept in culture-medium. Vessels including culture-medium (controls) and test solutions were kept under the same conditions as the test vessels for concentration analysis. Concentration-analysis was performed at 0 h and 72 h. The Alga-Test was carried without adjustment of the pH.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Desmodesmus subspicatus (Chlorophyceae, Chlorococcales),
- Strain: SAG 86.81
- Source (laboratory, culture collection): Albrecht von Haller Institut für Pflanzenwissenschaften der Universität Göttingen
- Method of cultivation: Sterile on agar tubes (0.8 % Agar). Transferred to a new agar tube every 2 months.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24.2 to 24.7 degree C

pH:

in the flasks at 0 h:
7.7 to 8.0

in the flasks at 72 h:
9.6 to 10.5

The test item had a significant effect on the pH of the test solutions at the start of the exposure period.

Salinity:

NA

Nominal and measured concentrations:

Nominal test concentrations: Control, 25.0 mg/L, 50.0 mg/L, 100 mg/L, 200 mg/L, 400 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL Erlenmeyer flasks (test volume 100 mL)
- Aeration: none
- Initial cells concentration: 5000 cells/mL
- No. of vessels per test group (replicates): 3
- No. of vessels per control group (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 400 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

80 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

112 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Details on results:

The test item had no significant effect on the pH of the test solutions at the start of the exposure period. The increase of pH in the control and test concentrations of 25.0 to 400 mg/L during the exposure period is caused by the growth of the algae in the test vessels. In common with other species of freshwater algae, Desmodesmus subspicatus gains CO2 from HCO3-, leading to a release of hydroxide ions, that raise the pH of the medium. In the test the increase of pH in the control of 2.6 (> 1.5 units as recommended in OECD-Guideline 201) had no effect on the growth of the algae as the validity criteria for algal growth were fulfilled.

Reported statistics and error estimates:

The Kolmogorov-Smirnov-test determined normality of the data (α = 0.05). The results of a one-way ANOVA showed a significant effect on the specific growth rate [µ] in the presence of Lithium chloride (F = 132.8; F critical = 5, 12, α = 0.05 = 3.11). Bartlett`s test detected homogeneity of variances(α = 0.05). Dunnett`s test for comparison of the treatment groups with the control showed significant differences between the control and the effective concentrations of 50.0, 100, 200 and 400 mg/L (α = 0.05).

Concentration of the Test item, cells/mL in the test flasks at 72 h, average specific growth rate [µ]over the whole testing period 0-72 h, mean value of the average specific growth rate [u], standard deviation and coefficient of variation Vc[%], inhibition [%] and mean value of inhibition [%] of the average specific growth rate [µ]in the Definitive Test:

Concentration [mg/L]	Cells / mL	Average Specific growth rate [u]	Average Specific growth rate [u] Mean value	Standard deviation	Coefficient of variation Vc [%]	Inhibition of Average Specific growth rate [%]	Inhibition of Average Specific growth rate Mean value [%]
	72 h	0-72 h	0-72 h	0-72 h	0-72 h	0-72 h	0-72 h
Control 1	720000	1.66	1.66	0.01	0.90
Control 2	752000	1.67
Control 3	688000	1.64
25.0	720000	1.66	1.66	0.01	0.87	-0.01	-0.52 *
25.0	720000	1.66				-0.01
25.0	776000	1.68				-1.52
50.0	576000	1.58	1.56	0.02	1.26	4.48	5.65 **
50.0	544000	1.56				5.63
50.0	512000	1.54				6.85
100	288000	1.35	1.42	0.07	4.59	18.4	14.2 **
100	424000	1.48				10.6
100	368000	1.43				13.5
200	248000	1.30	1.28	0.03	2.64	21.4	22.6 **
200	248000	1.30				21.4
200	208000	1.24				25.0
400	144000	1.12	1.11	0.02	2.05	32.4	33.2 **
400	128000	1.08				34.8
400	144000	1.12				32.4

* Remark: A negative inhibition value means an enhancement of the parameter.

** Significant difference compared to the control according to Dunnett`s test (p = 0.05).

Validity criteria fulfilled:

yes

Conclusions:

In this 72-h algal growth inhibition test with Desmodesmus subspicatus the 72-h EC50 based on growth rate was determined as greater than 400 mg/L. The overall NOEC was determined to be 25 mg/L. The results are based on the nominal concentrations.

Executive summary:

The effect of lithium chloride on the growth of an algal species Desmodesmus subspicatus over a 72 hour static exposure period was assessed according to OECD guideline 201. The test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test item in culture-medium for the range-finding test and from a stock solution of 400 mg/L of the test item in culture medium for the definitive test, respectively. The stock solutions and the corresponding dilutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes). The test solutions were clear at all test concentrations. The controls were kept in culture medium. Vessels including culture-medium (controls) and test solutions were kept under the same conditions as the test vessels for concentration analysis. AES-analysis confirmed that the test solutions were correctly dosed, i.e., the recoveries were within 91.9 to 98.2 % of the nominal concentrations at study start. At the end of the exposure, i.e., after 72 hours, the recoveries ranged from 92.4 to 97.8 % of the nominal concentrations demonstrating that the lithium concentrations were stable throughout the exposure period. Consequently, the results of the definitive test were based on nominal concentrations. In this 72-h algal growth inhibition test with Desmodesmus subspicatus

- the 72-h EC50 based on growth rate was determined as greater than 400 mg lithium chloride/L,

- the overall NOEC was determined to be 25 mg Lithium chloride/L.

The results are based on the nominal concentrations.

Description of key information

IBased on read-across approach, the calculated EC50 and NOEC for lithium chloride are 155 and 10 mg/L, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

155 mg/L

EC10 or NOEC for freshwater algae:

10 mg/L

Additional information

A toxicity study on algae with lithium chloride is available. Furthermore read-across was applied using characteristically similar compounds. Three guideline and GLP compliant studies are available for the salts lithium hydroxide, lithium chloride and lithium carbonate. All three studies were performed under static conditions according to OECD guideline 201 in Pseudokirchneriella subcapitata (LiOH monohydrate, with pH adjustment) and Desmodesmus subspicatus (LiCl, Li2CO3 without pH adjustment).

 

Key study

The influence of the test item lithium hydroxide monohydrate on the growth of Pseudokirchneriella subcapitata was investigated in a 72 h static test according to EU method C.3 and OECD Guideline No. 201. The test item had a statistically significant inhibitory effect on the growth based on the average specific growth rate, yield and areas under the curves of Pseudokirchneriella subcapitata after the exposure period of 72 hours in the concentration range of 20 - 160 mg/L test item/L (Bonferroni t-Test, alpha=0.05). The test concentration of 20 mg/L was determined as the 72-hour LOEC. The results showed an EC50 value of 41.62 mg/L based on biomass and 153.44 mg/L based on growth rate (equivalent to 23.75 mg/L resp. 87.57 mg/L referred to lithium hydroxide anhydrous). The NOEC based on growth rate for lithium hydroxide monohydrate was 10 mg/L. The NOEC calculated for lithium hydroxide anhydrous was 5.71 mg/L. (Toxi-Coop, 2010)

 

Supporting study

The effect of lithium chloride on the growth of the algal species Desmodesmus subspicatus over a 72 hour static exposure period was assessed according to OECD guideline 201. The test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test item in culture medium for the range-finding test and from a stock solution of 400 mg/L of the test item in culture medium for the definitive test, respectively. The stock solutions and the corresponding dilutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes). The test solutions were clear at all test concentrations. The controls were kept in culture medium. Vessels including culture medium (controls) and test solutions were kept under the same conditions as the test vessels for concentration analysis. AES-analysis confirmed that the test solutions were correctly dosed, i.e. the recoveries were within 91.9 to 98.2 % of the nominal concentrations at study start. At the end of the exposure, i.e. after 72 hours, the recoveries ranged from 92.4 to 97.8 % of the nominal concentrations demonstrating that the lithium concentrations were stable throughout the exposure period. Consequently, the results of the definitive test were based on nominal concentrations. In this 72-h algal growth inhibition test with Desmodesmus subspicatus the 72-h EC50 based on growth rate was determined as greater than 400 mg/L. The overall NOEC was determined to be 25 mg/L. The results are based on the nominal concentrations. (Steinbeis, 2010)

 

Supporting study

The effect of lithium carbonate on the growth of an algal species Desmodesmus subspicatus over a 72-hour static exposure period was assessed according to OECD guideline 201. The test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test item in culture medium for the range-finding test and from a stock solution of 400 mg/L of the test item in culture medium for the definitive test, respectively. The stock solutions and the corresponding dilutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes). The test solutions were clear at all test concentrations. The controls were kept in culture medium. Vessels including culture medium (controls) and test solutions were kept under the same conditions as the test vessels for concentration analysis. Concentration analysis was performed at 0 h and 72 h. The Alga-test was carried without adjustment of the pH.AES-analysis confirmed that the test solutions were correctly dosed, i.e., the recoveries were within 92.4 to 103 % of the nominal concentrations at study start. At the end of the exposure, i.e., after 72 hours, the recoveries ranged from 95.9 to 103 % of the nominal concentrations demonstrating that the lithium concentrations were stable throughout the exposure period. Consequently, the results of the definitive test were based on nominal concentrations.In this 72-h algal growth inhibition test with Desmodesmus subspicatus the 72-h EC50 based on growth rate was determined as greater than 400 mg/L for lithium carbonate. The overall NOEC was determined to be 50 mg/L for lithium carbonate (the calculated NOEC for lithium ion: 9.39 mg/L) . The results are based on the nominal concentrations. (Steinbeis, 2010)

 

Conclusion

The highest toxicity was noted in Pseudokirchneriella subcapitata with LiOH. As the pH was adjusted, pH effects can be excluded. The two other salts were tested in Desmodesmus subspicatus revealing significantly lower toxicity. As a consequence, the EC50 and NOEC values for Li+ obtained in Pseudokirchneriella subcapitata are taken as starting figures to derive the respective values for lithium chloride. A NOEC of 10 mg/L was calculated.