Lithium nickel potassium oxide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

STUDY COMPLETED
08 Feb 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Commission Regulation (EC) No 440/2008, C.2 OECD 202

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Remarks:

Test temperature: 19.3 – 19.8°C (continuous monitoring) Detailed records are kept in facility archives to monitor health of Daphnia brood stock cultures including observations of young production, mortality, ephippia, and measurement of water chemistry.

Details on sampling:

The test substance contains lithium and nickel. The nickel content was determined in prepared
test solutions.
Samples for concentration control analysis were taken from each freshly prepared solution (0 h
and 24 h) without daphnids and at the end of each exposure interval (after approx. 24 h and
48 h) from all test vessels with mobile daphnids. All samples were collected with a glass pipette
and placed into glass sample vials (5 mL sample volume).

Vehicle:

no

Details on test solutions:

TEST SUBSTANCE PREPARATIONS
The test substance is poorly water soluble; the stock solution was prepared following general
guidance provided in OECD 23. A stock solution was prepared by directly adding 100
mg of test substance to 1L test medium and stirring for about 2 days. Undissolved test
substance was removed by filtration with a membrane filter (pore width 0.2 μm, Whatman OE
66). The first 100 mL of filtered solution were discarded (used to condition the filter). The
aqueous fraction was inspected visually for the presence of any undissolved test substance by
observing the scattering of a laser light through the test solution (Tyndall effect) and the Tyndall
effect was negative. The aqueous fraction of the test solution, after separation of the
undissolved material, was considered the water saturated fraction (WSF) in test media.

After filtering the solution was stirred for 10 min to ensure adequate dissolved oxygen levels.
The control was treated in the same way but without test substance.
Fresh test solutions were prepared daily.

Test organisms (species):

Daphnia magna

Details on test organisms:

Test species: Daphnia magna STRAUS
Reason for selection of the test species:
Recommended species in the test guidelines.
Origin: The clone of Daphnia magna STRAUS 1820 used was supplied by the Institut National de Recherche Chimique Appliquée, France, in 1978.
From this date on this clone was cultured and bred continuously in the Ecotoxicology Laboratory of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen Germany.

Test type:

static

Water media type:

other: Synthetic fresh water (Elendt M4) prepared according to OECD 202.

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

This study investigated the effect of the test substance on the immobilisation of Daphnia
magna. Juvenile daphnids (<24 hour old) were exposed to concentrations of the test substance
and compared to a control. Immobilisation is determined after 24 and 48

Hardness:

2.20 – 3.20 mmol/L

Test temperature:

20 ±1°C

pH:

7.5 – 8.5

Dissolved oxygen:

Must remain ≥3mg/L during the test. To
assure optimal dissolved oxygen levels, the M4 medium is
aerated for approximately 24 hours prior to use.

Conductivity:

550 - 650 μS/cm

Nominal and measured concentrations:

TEST GROUPS AND CONCENTRATIONS
Test groups : 0 (control) and 100 mg/L as nominal concentrations based on test substance mass without correction for purity
Replicates / test group: 4 replicates with test animals (5 animals per replicate)
Daphnids / test group: 20
Reason for the selection of the test concentrations:
In a preliminary test a concentration of 100 mg/L caused no immobilisation or symptoms after 48 hours.
According to the OECD test guideline, the highest suggested test concentration is 100 mg/L for a limit test.

Details on test conditions:

Test species: Daphnia magna STRAUS
Reason for selection of the test species:
Recommended species in the test guidelines.
Origin: The clone of Daphnia magna STRAUS 1820 used was supplied by the Institut National de Recherche Chimique Appliquée, France, in 1978.
From this date on this clone was cultured and bred continuously in the Ecotoxicology Laboratory of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen Germany.

Culture conditions: Daphnia brood stock are kept in mass cultures consisting of approx. 20 – 30 parthenogenetically reproducing females for a maximum of 4 weeks and fed live unicellular algae
(Desmodesmus subspicatus), cultured continuously at the test facility. All individuals in each mass culture originate from a single female and are thus genetic clones. After approximately
14 days the adults have produced at least 3 broods and the young can be used in tests. Offspring are removed from the mass cultures at least once daily during the normal work week to ensure that young daphnia are <24-h old (first instar) at start of the exposure. Detailed records are kept (in test facility archives) to monitor the health of Daphnia brood stock cultures including observations of young production, mortality, ephippia, and measurement of water chemistry parameters. Only young from healthy cultures without signs of stress are used for testing.

Acclimatization: The Daphnia are cultured under the identical conditions as the test including test media (Elendt M4), water quality, and temperature (20 ±1°C).

Age at start of exposure: <24 hours (at least 3rd brood progeny)

Reference substance testing:
In order to verify that the Daphnia magna culture is responding normally to toxic stress, tests with a reference substance, sodium chloride, are conducted monthly. Reference substance tests are conducted according to OECD 202 guidelines and in accordance with GLP, but without a GLP status.
The EC50(48h) of the reference substance sodium chloride was 4.91 g/L (experiment date: 21 Aug 2018, project number: 50E0789/12E060).

This result is within the range of 3.88 – 7.22 g/L and indicates that the culture of Daphnia magna used in this study is responding normally to toxic stress.

HOUSING AND DIET
Culture media: synthetic fresh water (Elendt M4) prepared according to OECD
202. See also 3.7.
Temperature: 20 ±1°C
Photoperiod: 16 hours light, 8 hours dark
Diet: Unicellular green algae, Desmodesmus subspicatus, (cultured
continuously at the testing laboratory)
Feeding: Daily
Renewal of the culture water: Twice weekly

TEST SUBSTANCE PREPARATIONS
The test substance is poorly water soluble; the stock solution was prepared following general
guidance provided in OECD 23. A stock solution was prepared by directly adding 100
mg of test substance to 1L test medium and stirring for about 2 days. Undissolved test
substance was removed by filtration with a membrane filter (pore width 0.2 μm, Whatman OE
66). The first 100 mL of filtered solution were discarded (used to condition the filter). The
aqueous fraction was inspected visually for the presence of any undissolved test substance by
observing the scattering of a laser light through the test solution (Tyndall effect) and the Tyndall
effect was negative. The aqueous fraction of the test solution, after separation of the
undissolved material, was considered the water saturated fraction (WSF) in test media.

After filtering the solution was stirred for 10 min to ensure adequate dissolved oxygen levels.
The control was treated in the same way but without test substance.
Fresh test solutions were prepared daily.

Concentration control analysis
The test substance contains lithium and nickel. The nickel content was determined in prepared
test solutions.
Samples for concentration control analysis were taken from each freshly prepared solution (0 h
and 24 h) without daphnids and at the end of each exposure interval (after approx. 24 h and
48 h) from all test vessels with mobile daphnids. All samples were collected with a glass pipette
and placed into glass sample vials (5 mL sample volume).

EXPERIMENTAL PROCEDURE
Test medium: A synthetic fresh water (Elendt M4) is used as media for culture and test purposes. For the composition of this M4 medium see OECD 202. The general properties of this medium are as follows.
Total hardness: 2.20 – 3.20 mmol/L
Acid capacity up to pH 4.3: 0.80 – 1.00 mmol/L
Molar ratio Ca:Mg: about 4 : 1
pH value: 7.5 – 8.5
Conductivity: 550 - 650 μS/cm
Total organic carbon: <2 mg/L
Dissolved oxygen: Must remain ≥3mg/L during the test. To
assure optimal dissolved oxygen levels, the M4 medium is
aerated for approximately 24 hours prior to use.

Test vessels : Numbered glass beakers (nominal volume 100 mL)
Test volume: 50 mL
Test solution renewal: Static-renewal exposure via test water. The renewal period was
24 hours.
Test temperature: 19.3 – 19.8°C (continuous monitoring)
Biological loading: 5 animals / test vessel (0.1 animals/mL)
Light intensity / Photo period:
114 – 639 lux at a wave length of 400 – 750 nm;
16 hours light : 8 hours darkness
Aeration: none
Diet: No feeding during the exposure period.

The exposure was started by impartially distributing 20 neonate (< 24 hours old) Daphnia
magna evenly among the 4 test vessels per test group. The neonate daphnids all originated
from the same mass culture and were thus genetic clones. The Daphnia were
transferred into the test vessels with minimal culture water by capturing each daphnid in a
pipette then gently expelling it onto a Teflon mesh (70 μm) held by forceps. Each daphnid was
then immediately transferred from the mesh into the corresponding test vessel from lowest to
highest concentration.

Each test vessel was visually checked for immobilized daphnids after 0, 24 and 48 hours. In
addition any abnormal behavior or appearance was documented.

For test renewal, daphnids in each replicate were captured with a pipette and transferred into
test vessels with fresh test solution.

Throughout the test, the appearance of the test solutions and dissolution behavior of the test
substance was observed and recorded daily in old and new test solutions.

The chemical and physical parameters of the test medium (total hardness, acid capacity, pH,
TOC and conductivity) were determined after aeration and prior to use in the test.

The pH and dissolved oxygen content of the test solutions was measured after 0h and 24h
(new test solutions) in an additional replicate without daphnids and after 24 h and 48 h (old test
solutions) in replicate 1 of each tested concentration.

In addition, temperature was measured continuously during the whole exposure period in a
separate vessel filled with water proximal to the test vessels.

DATA EVALUATION
All reported data values are rounded to the appropriate significant
figures based on the precision of the analytical method and/or consistent with the requirements
in the pertinent test guideline(s).

Since the study is designed as a limit test, the data were not appropriate for the use of
computerized methods for the calculation of ECx values. Any LOEC, NOEC and ECx values
are estimated based on expert judgment in accordance with test guideline recommendations.

VALIDITY CRITERIA
This test was fully compliant with all the following validity criteria required by the corresponding
test guidelines and is considered valid.
• ≤10% immobilisation in the control
• O2 concentration ≥3 mg/L in control and test vessels

Reference substance (positive control):

yes

Remarks:

Reference substance: Name of reference substance: sodium chloride Reference substance No.: 12/0789-2 Batch identification: 1681499 CAS No.: 7647-14-5

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water-saturated fraction (WSF): aqueous fraction of test solution after active separation of the undissolved material (e.g. via centrifugation or filtration)

Basis for effect:

mortality

Details on results:

ANALYTICAL CONCENTRATION CONTROL
Since the test substance is a poorly water soluble inorganic chemical, only the dissolved content of the constituent element (nickel) was analytically determined. All reasonable efforts were taken to produce a saturated solution of the test substance in test media, following the guidance in OECD 23. According to OECD 23, for tests with chemicals that can not be quantified by analytical methods at the concentrations causing effects, the effect concentration can be expressed based on the nominal concentrations (the loading rate). According to the preliminary information of the Competence Center Analytics of BASF SE, the component (nickel) was measured at the tested loading rate, which indicates that test item must have been present.

CONCLUSION
In a 48-hour acute toxicity study, neonate Daphnia magna were exposed to KDLNO at loading rates of 0 (control) and 100 mg/L under daily-renewal conditions in accordance with the OECD 202 guideline. The water pH, temperature and dissolved oxygen were within acceptable guideline specifications. Immobilization (mortality) and sublethal effects were observed daily.

The 48 hour EC50 values determined in this acute toxicity study were:
EC50 / EL50 > 100 mg/L

No toxic effects were observed up to the water solubility limit of the test substance. Since the test substance is a poorly water soluble inorganic chemical, only the dissolved content of the constituent element (nickel) was analytically determined. All reasonable efforts were taken to produce a saturated solution of the test substance in test media, following the
guidance in OECD 23. According to OECD 23, for tests with chemicals that can not be quantified by analytical methods at the concentrations causing effects, the effect concentration can be expressed based on the nominal concentrations (the loading rate).

The toxicity results presented here are consistent with the results from preliminary tests. The results in this study are consistent with all validity criteria and the test is valid according to the guidelines of this study. No deviations from test guidelines or other incidents occurred during the course of the reported test which may have influenced the results.

Results with reference substance (positive control):

In order to verify that the Daphnia magna culture is responding normally to toxic stress, tests with a reference substance, sodium chloride, are conducted monthly. Reference substance tests are conducted according to OECD 202 guidelines and in accordance with GLP, but without a GLP status.
The EC50(48h) of the reference substance sodium chloride was 4.91 g/L
This result is within the range of 3.88 – 7.22 g/L and indicates that the culture of Daphnia magna used in this study is responding normally to toxic stress.

Validity criteria fulfilled:

yes

Conclusions:

The following effect concentrations (mg/L) were obtained after 48
hours based on nominal (loading) concentrations:
EC50 / EL50 > 100 mg/L

No toxic effects were observed up to the water solubility limit of the
test substance.

The test organisms were exposed to a saturated solution of the test substance at the given loading rate and the effect concentration should be expressed based on the loading rate as recommended in OECD 23.

Executive summary:

In a 48-hour acute toxicity study, neonate Daphnia magna were exposed to KDLNO at loading rates of 0 (control) and 100 mg/L under daily-renewal conditions in accordance with the OECD 202 guideline. The water pH, temperature and dissolved oxygen were within acceptable guideline specifications. Immobilization (mortality) and sublethal effects were observed daily.

 

The 48 hour EC50 values determined in this acute toxicity study were:

EC50 / EL50 > 100 mg/L

 

No toxic effects were observed up to the water solubility limit of the test substance. Since the test substance is a poorly water soluble inorganic chemical, only the dissolved content of the constituent element (nickel) was analytically determined. All reasonable efforts were taken to produce a saturated solution of the test substance in test media, following the

guidance in OECD 23. According to OECD 23, for tests with chemicals that can not be quantified by analytical methods at the concentrations causing effects, the effect concentration can be expressed based on the nominal concentrations (the loading rate).

 

The toxicity results presented here are consistent with the results from preliminary tests. The results in this study are consistent with all validity criteria and the test is valid according to the guidelines of this study. No deviations from test guidelines or other incidents occurred during the course of the reported test which may have influenced the results.

 

Description of key information

In a 48-hour acute toxicity study, neonate Daphnia magna were exposed to KDLNO at loading rates of 0 (control) and 100 mg/L under daily-renewal conditions in accordance with the OECD 202 guideline. The water pH, temperature and dissolved oxygen were within acceptable guideline specifications. Immobilization (mortality) and sublethal effects were observed daily.

 

The 48 hour EC50 values determined in this acute toxicity study were:

EC50 / EL50 > 100 mg/L

 

No toxic effects were observed up to the water solubility limit of the test substance. Since the test substance is a poorly water soluble inorganic chemical, only the dissolved content of the constituent element (nickel) was analytically determined. All reasonable efforts were taken to produce a saturated solution of the test substance in test media, following the

guidance in OECD 23. According to OECD 23, for tests with chemicals that can not be quantified by analytical methods at the concentrations causing effects, the effect concentration can be expressed based on the nominal concentrations (the loading rate).

The toxicity results presented here are consistent with the results from preliminary tests. The results in this study are consistent with all validity criteria and the test is valid according to the guidelines of this study. No deviations from test guidelines or other incidents occurred during the course of the reported test which may have influenced the results.

 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

100 mg/L