Lithium bromide

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:

2010-04-30 to 2010-07-13

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP and guideline compliant study. Read-across was performed with lithium chloride. Please refer to IUCLID section 13 for read-across justification.

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
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

Post exposure observation period:

no

Test temperature:

24.2 to 24.7 °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.

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

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

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 [u] 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 [u] 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 were 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 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.

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:

HYPOTHESIS FOR THE ANALOGUE APPROACH
Lithium bromide completely dissociates in water forming lithium cation and the corresponding bomide anion. Thus, lithium salts with different anion moieties and bromide compounds were found to be suitable candidates for read-across. (Eco)toxicological properties were extrapolated to different endpoints by using the lowest effect concentration.
For further information, please refer to the read-across justification in IUCLID, section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

164 mg/L

Nominal / measured:

nominal

Conc. based on:

other: recalculated for LiBr

Remarks on result:

other: Based on LiCl (STZ 04-10-001, 2010)

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 820 mg/L

Nominal / measured:

nominal

Conc. based on:

other: recalculated for LiBr

Remarks on result:

other: Based on LiCl Based on LiCl (STZ 04-10-001, 2010)

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

51 mg/L

Nominal / measured:

nominal

Conc. based on:

other: recalculated for LiBr

Remarks on result:

other: Based in LiCl Based on LiCl (STZ 04-10-001, 2010)

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

HYPOTHESIS FOR THE ANALOGUE APPROACH
Lithium bromide completely dissociates in water forming lithium cation and the corresponding bomide anion. Thus, lithium salts with different anion moieties and bromide compounds were found to be suitable candidates for read-across. (Eco)toxicological properties were extrapolated to different endpoints by using the lowest effect concentration.
For further information, please refer to the read-across justification in IUCLID, section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

EC10

Effect conc.:

ca. 2 870 mg/L

Nominal / measured:

nominal

Conc. based on:

other: recalculated for LiBr

Remarks on result:

other: Based on NaBr (Kühn et al, 1990)

Reference 4

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Only handbook or publsihed data. Read-across was performed with sodium bromide. Please refer to IUCLID section 13 for read-across justification.

Qualifier:

according to guideline

Guideline:

other: Test was conducted in accordance with DIN 38 412, Part 9

Deviations:

no

GLP compliance:

no

Analytical monitoring:

yes

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: 8681 SAG
- Source (laboratory): permanent culture
- Age of inoculum (at test initiation): 10 days

ACCLIMATION
- Culturing media and conditions: same as test
- Any deformed or abnormal cells observed: no

Test type:

static

Water media type:

freshwater

Total exposure duration:

4 d

pH:

8

Nominal and measured concentrations:

0.156 to 20 g/L

Details on test conditions:

TEST SYSTEM
- Initial cells density: 10E4 cells/mL
- Control end cells density:
- No. of vessels per concentration (replicates): 2
- No. of vessels per vehicle control (replicates): 2

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Conductivity:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH: yes
- Photoperiod: permanent light

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: spectrophotometer

TEST CONCENTRATIONS
- Spacing factor for test concentrations: factor 2

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

EC10

Effect conc.:

ca. 3 400 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no

Conclusions:

In this 96-h algal growth inhibition test with Desmodesmus subspicatus the 96-h EC10 based on growth rate was determined to be 3400 mg/L. The results were based on the nominal concentrations.

Executive summary:

The effect of sodium bromide on the growth of an algal species Desmodesmus subspicatus over a 96-hour static exposure period was assessed according to DIN 38412 Part 9. The test solutions were prepared in a dilution series from a stock solution. The stock solutions and the corresponding dilutions were prepared using a mixing device. 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. The results of the test were based on nominal concentrations.In this 96-h algal growth inhibition test with Desmodesmus subspicatus the 96-h EC10 based on growth rate was determined as 3400 mg/L. (UBA, 1990)

Description of key information

In this 72-h algal growth inhibition test with lithium chloride in 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. Based on read across approach, the calculated 72-h EC10 is 164 mg/L, the 72-h EC50 is greater than 820 mg/L and the overall NOEC is 51 mg/L for lithium bromide.

Key value for chemical safety assessment

EC50 for freshwater algae:

820 mg/L

EC10 or NOEC for freshwater algae:

51 mg/L

Additional information

Key study

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 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)

Based on read-across approach, the calculated 72-h EC10 is 164 mg/L, the 72-h EC50 is greater than 820 mg/L and the overall NOEC is 51 mg/L for lithium bromide.

Supporting data

The effect of sodium bromide on the growth of an algal species Desmodesmus subspicatus over a 96-hour static exposure period was assessed according to DIN 38412 Part 9. The test solutions were prepared in a dilution series from a stock solution. 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. The results of the test were based on nominal concentrations.

In this 96-h algal growth inhibition test with Desmodesmus subspicatus the 96-h EC10 based on growth rate was determined as 3400 mg/L. (UBA, 1990)

Based on read-across approach, the calculated 48-h EC10 is 2870 mg/L for lithium bromide.