Manganate(1-), glycinato-N,O)[sulfato(2-)-O]-, hydrogen

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Water flea Daphnia magna were exposed to varying concentrations of several metal salts. 5 mg/L and 10 mg/L MnCl2 was dissolved in lake water. The daphnids were treated for 48h in the acute test to evaluate the LC50 value. Animals were not fed during the experiment and the test was conducted under static conditions.
- Short description of test conditions: For acute tests, 10 daphnids 12 ± 12 hr old were placed in duplicate test chambers and subjected to test conditions for 2 days (48 hr).Analytical measurements in test containers were made for Na, Ca, Mg, Fe, Mn, Zn, and Cd at the time of addition and 1 week later.Dissolved oxygen were near saturation at all times. Measurements of pH were made in test containers when the medium was added. Daphnids were fed a suspension of food (1 ml/liter) twice weekly for rearing. The food suspension was prepared by adding 0.5 g of powdered dried grass and 10 g of enriched trout-fry granules to 250 ml of Lake Superior water and mixing vigorously in a blender for 5 min. The suspension was then strained through #20 bolting cloth. The blender was rinsed with an additional 50 ml of lake water, and the rinse water was added to the suspension. Unfiltered lake water strained through #20 bolting cloth was used for all rearing; thus, in addition to the food mixture, the daphnids obtained some nutrients from bacteria, algae, and detritus in the water.
- Parameters analysed / observed: Complete immobilization or death was the endpoint.

GLP compliance:

no

Remarks:

Study was conducted prior to implementation of GLP and OECD guidelines

Analytical monitoring:

yes

Remarks:

Please refer to any other information on materials and methods

Details on sampling:

- Concentrations: All concentrations were analysed
- Sampling method: Please refer to any other information on materials and methods
Analytical measurements in test containers were made for Na, Ca, Mg, Fe, Mn, Zn, and Cd at the time of addition and 1 week later.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: American Chemical Society reagent-grade chemicals were used for all testing.Fresh stock solutions were prepared in lake water for each experiment.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Daphnia magna
- Age at study initiation (mean and range, SD): 12 ± 12 h old
- Source: University of Michigan
- Feeding during test
They were fed a suspension of food (1 ml/liter) twice weekly for rearing and once weekly for testing. The food suspension was prepared by adding 0.5 g of powdered dried grass and 10 g of enriched trout-fry granules to 250 ml of Lake Superior water and mixing vigorously in a blender for 5 min. The suspension was then strained through #20 bolting cloth. The blender was rinsed with an additional 50 ml of lake water, and the rinse water was added to the suspension. The food thus prepared was stored in a refrigerator and mixed thoroughly each time an aliquot was withdrawn. Un-filtered lake water strained through #20 bolting cloth was used for all rearing and testing; thus, in addition to the food mixture, the daphnids obtained some nutrients from bacteria, algae, and detritus in the water.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

44-53 mg/L

Test temperature:

18 ± 1°C

pH:

7.4-8.2

Dissolved oxygen:

saturated solution

Nominal and measured concentrations:

nominal concentrations: 5, 10 mg/L; measured concentrations: 4.6-4.9 mg/L and 9.1-9.9 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: duplicate test chambers
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): duplicates

TEST MEDIUM / WATER PARAMETERS
Characteristics Lake Superior water:
Item Mean Range samples
pH 7.74 7.4-8.2 23
Total hardness 45,300 44,000-53,000 54
Alkalinity 42,300 41 ,000-50,000 54
Chloride 1217 1170-1340 18
Sodium 1130 1090-1190 23
Calcium 13,695 13,000-14,700 23
Magnesium 3123 2940-3590 23
Potassium 534 480-590 23
Strontium 16 12-27 10
Barium 14 8-22 10
Iron 23 2-83 10
Manganese - 0.2-11.5 23
Chromium - 2-20 4
Aluminum - 1-26 5
Zinc 0.78 1-2.7 21
Nickel <0. 5 - 23
Lead - 7-20 2
Copper 1 .51 0.3-3.2 23
Cobalt <0. 5 - 23
Mercury <0 .01 - 5
Cadmium <0 . 1 - 23
OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: 16h
- Light intensity: 115 ft-c

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and immobilization

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

9.8 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Mn2+

Basis for effect:

mortality

Details on results:

No further observations were reported.

Reported statistics and error estimates:

Results were statistically evaluated with the method of Litchfield and Wilcoxon (1949) for establishing approximations of the 95% confidence limits for survival.The terminology recommended by Sprague (1969),lethal concentration (LC), was used for survival and, as given here, represents an interpolation from three or more partial-effect concentrations.

Validity criteria fulfilled:

not applicable

Conclusions:

In the present publication of Biesinger & Christensen (1972) Daphnia magna were exposed to 5 and 10 mg/L Manganese (MnCl2) for 48h under static conditions. The LC50 was determined to be 9.8 mg Fe2+/L

Executive summary:

The 48-hr-acute toxicity of MnCl₂to Daphnia magna was studied under static conditions.  Daphnids were exposed to control and test chemical at 5 mg/L and 10 mg/L MnCl₂in lake water for 48 h.

Complete immobilization or death was the endpoint measured after 48h.

Mortality/immobilization was observed daily. 

The 48-hour LC50 for Daphnia magna was 9.8 mg Mn²⁺/L without food, which corresponds to 40.35 mg manganese monoglycinate sulfate/L.

 

This study is classified as acceptable as it was conducted according to generally accepted scientific principles and satisfies the requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

Test Organism Age: adult Isopods and Amphipods

Test Type: Static Renewal

 

LC50 Daphnia magna: 9.8 mg Mn²⁺/L

Endpoint(s) Effected:  mortality

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test:
Test similar to OECD 202.
- Short description of test conditions:
Static tests were conducted for 96h in a 13°C constant temperature room, under a 12h light cycle. Soft water was used, with a total hardness of 50 ppm (as calcium carbonate). This complies with that recommended for static toxicity tests. New 200 cm³ polystyrene beakers were used as the experimental containers, and between 20-30 amphipods or 10 isopods were placed in each. Animals were not fed during testing, nor was aeration found to be necessary. Solutions were changed every 24 h after which time ammonia and oxygen concentrations were found to be still well within acceptable limits. Since the pH of aqueous solutions tends to change when metal salts are added (Stumm and Morgan, 1981), pH was also checked at 24 and 72 h. Initial range-finding tests were used to derive the concentrations suitable for LC50 determinations. For actual testing a minimum of eight concentrations (and a control) were used for each metal. Two replicates were used for all Asellus and most Crangonyx tests. The “death point” was taken as immobilization, determined by gentle probing of each animal. Post-exposure observations in clean water revealed that immobilized crustaceans did not recover. Mortalities were assessed at 24h intervals when the dead peracarids were removed.
- Parameters analysed / observed: Mortality

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solutions were prepared by dissolving the appropriate salt (MnCl2 x 4H2O) in deionized water
- Controls: No treatment

Test organisms (species):

other: Asellus aquaticus and Crangonyx pseudogracilils

Details on test organisms:

TEST ORGANISM
- Common name: Waterlouse (Isopod) and Amphipod
- Strain/clone: Asellus aquaticus and Crangonyx pseudogracilils
- Length at study initiation (length definition, mean, range and SD): Amphipods of mean size 4mm (approx. 0.2 mg dry wt) and isopods of 7 mm (1.5 mg dry wt) were selected for the tests (excluding ovigerous females)
- Stage and instar at study initiation: adult
- Method of breeding: Crangonyx pseudogracilis and Asellus aquaticur were obtained from self-maintaining cultures in open-air concrete stock tanks (2.5 m long x 1.2 m wide x 0.8 m deep). A slow flow of water from the Nottingham mains supply passes through the tanks which are used to house freshwater
crayfish. In the tanks, an excess of food is available in the form of filamentous algae (Cladophora spp) and organic detritus (mainly decaying leaves).
- Source: The original source for the Crangonyx was Nottingham Canal, a disused and “clean” static water body north-west of Nottingham. More than one source may have contributed to the stock population of Asellus but, as with the Crangonyx, the captive population had been established for more than a year prior to the tests.
ACCLIMATION
- Acclimation period: Animals were acclimated for a week prior to experimentation.
- Type and amount of food: During this time the animals were fed ad Iibitum upon trout-fry pellets. No aeration was provided.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Post exposure observation was performed and revealed that immobilised crustaceae do not recover.

Hardness:

within 5 ppm

Conductivity:

325µS/cm

Nominal and measured concentrations:

8 concentrations were tested.

Details on test conditions:

TEST SYSTEM
- Test vessel: 200 cm³ polystyrene beakers
- Aeration: No
- No. of organisms per vessel: 20-30 amphipods or 10 isopods were placed in each
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water was prepared by adding tap water to mdeionized water in the approximate ratio of 1:3, to achieve the desired hardness to within 5 ppm.
- Conductivity: 325 µS/cm

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality/Immobilisation

VEHICLE CONTROL PERFORMED: no

Key result

Duration:

96 h

Dose descriptor:

LC50

Remarks:

Crangonyx pseudogracilis

Effect conc.:

694 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Mn2+

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

LC50

Remarks:

Crangonyx pseudogracilis

Effect conc.:

1 389 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Mn2+

Basis for effect:

mobility

Reported statistics and error estimates:

24, 48, 72 and 96 h LC50 values and 95% confidence limits were derived from weighted regressions of log metal concentration (as ppm of metal added)/probit (=transformed percentage) mortality (Finney, 1971). Results from replicates were pooled. For reasons of space, only the 48 and 96 h values are presented. In each case, goodness of fit of the regression model was verified by the Chi-square statistic. The complete probit analysis was carried out using a BBC model B micro-computer running a modified version of an “Apple-soft“ BASIC program by Liebennan (1983). It should be emphasized that LC50 were derived from nominal rather than measured concentrations of metal ions.

Validity criteria fulfilled:

not applicable

Conclusions:

In the present study the 96 h LC50 value of Mn2+ ions was determined in Crangonyx pseudogracilis. 20 Crangonyx pseudogracilis were exposed to at least 8 concentrations of Mn2+ under static conditions. Immobilisation was used as parameter to determine toxicity or death point.
The LC 50 value for Crangonyx pseudogracilis was 694 mg Mn2+/L after 96h incubation which correponds to 2.86 g manganese monoglycinate sulfate/L.

Executive summary:

The 96-hr-acute toxicity of MnSO₄to Asellus aquaticus and Crangonyx pseudogracilils was studied under static conditions.  Snails were exposed to control and test chemical at eight in soft water for 96 h.

The “death point” was taken as immobilization, determined by gentle probing of each animal. Post-exposure observations in clean water revealed that immobilized crustaceans did not recover. Mortalities were assessed at 24h intervals when the dead peracarids were removed.

Mortality/immobilization was observed daily. 

The 96-hour LC50 for Crangonyx pseudogracilis was 694 mg Mn²⁺/L which corresponds to 2.86 g manganese monoglycinate sulfate/L.

 

This study is classified as acceptable as it was conducted according to generally accepted scientific principles and satisfies the requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

Test Organism Age: adult Isopods and Amphipods

Test Type: Static Renewal

 

LC50 C. pseudogracilis: 694 mg Mn²⁺/L

Endpoint(s) Effected:  mortality

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
ECOSAR v 1.11
2. MODEL (incl. version number)
ECOSAR v 1.11; The ECOSAR (ECOlogical Structure Activity Relationship) Class Programm for Microsoft Windows; U.S. Environmental Protection Agency; Office of Chemical Safety and Pollution Prevention (Kelly Mayo-Bean, June 19, 2012)
3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
CAS: 56-40-6
4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
For more detailed information please refer to the 'attached justification' section
5. APPLICABILITY DOMAIN
For more detailed information please refer to the 'attached justification' section
6. ADEQUACY OF THE RESULT
For more detailed information please refer to the 'attached justification' section

Qualifier:

no guideline followed

Principles of method if other than guideline:

QSAR prediction of dose descriptors using EPISuite ™, The ECOSAR (ECOlogical Structure Activity Relationship) Class Programm for Microsoft Windows; U.S. Environmental Protection Agency; Office of Chemical Safety and Pollution Prevention (Kelly Mayo-Bean, June 19, 2012).

GLP compliance:

no

Analytical monitoring:

no

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

32 749.543 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other:

Remarks:

Value obtained from a QSAR estimation

Validity criteria fulfilled:

not applicable

Conclusions:

In the present QSAR prediction which was conducted using EPISuite ™, The ECOSAR (ECOlogical Structure Activity Relationship) Class Programm for Microsoft Windows; U.S. Environmental Protection Agency; Office of Chemical Safety and Pollution Prevention (Kelly Mayo-Bean, June 19, 2012) for glycine, the estiamted LC50 value for glycine was reported to be 32749.543 mg/L. The prediction is reliable because the substance falls into the applicability domain of the model. Moreover, cut-off values that limit the predictions reliability were not exceeded. Based on the presented results glycine does not need to be classified according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemicals (GHS).

Executive summary:

The LC50 value for glycine was predicted with EPISuite ™, The ECOSAR (ECOlogical Structure Activity Relationship) Class Programm for Microsoft Windows; U.S. Environmental Protection Agency; Office of Chemical Safety and Pollution Prevention (Kelly Mayo-Bean, June 19, 2012). Based on the chemical structure of glycine which reveals functional groups that are present in the training data sets of the model used, the substance is considered to fall in the applicability domain of ECOSAR. The LC50 value predicted for L-glycine is far above the 100 mg/L limit concentration. (32749.543 mg/L) and are more than 10 -fold higher than the water solubility. Thus, no toxic effects are expected to occur up to saturation limits. Based on these information glycine is considered to exhibit a very low toxicity to aquatic invertebrates.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Snails M. tuberculata were collected from canals in the university in Bangi, Selangor, Malaysia. The snails were exposed to five different Mn2+ concentrations under static conditions for four days. Mortality was recorded every 3 to 4 hours for the first two days and then at 12 to 24 hour intervals throughout the rest of the test period. The criterion used to determine mortality were failure to respond to gentle physical stimulation. The death was further confirmed by putting the snail on the glass petri dish for few minutes and if it did not show any movement, it was considered dead.
- Short description of test conditions: Prior to toxicity testing, the snails were acclimatized for one week under laboratory conditions (28–30°C with 12 h light : 12 h darkness) in 50-L stocking tanks using dechlorinated tap water (filtered by several layers of sand and activated carbon; T.C. Sediment Filter (TK Multitrade, Seri Kembangan, Malaysia)) aerated through an air stone. During acclimation the snails were fed on lettuce. During the toxicity test, the snails were not fed. The experiments were performed at room temperature of 28–30°C with photoperiod 12 h light : 12 h darkness, using fluorescent lights (334–376 lux). Water quality parameters (pH, conductivity, and dissolved oxygen) were measured every two days using portable meters (model Hydrolab Quanta, Hach, Loveland, USA) and water hardness samples were fixed with ARISTAR nitric acid and measured by flame atomic absorption spectrophotometer (AAS-Perkin Elmer model AAnalyst 800).
- Parameters analysed / observed: Mortality

GLP compliance:

no

Remarks:

GLP compliance was not reported in this publication

Analytical monitoring:

yes

Remarks:

metal analysis by flame or furnace Atomic Absorption Spectrophotometer (AAS- Perkin Elmer model AAnalyst800, Massachusetts, USA)

Details on sampling:

- Concentrations: The tests were carried out under static conditions with renewal of the solution every two days. Samples of water for metal analysis taken before and immediately after each solution renewal were acidified to 1% with ARISTAR nitric acid (65%) (BDH Inc, VWR International Ltd., England) before metal analysis by flame or furnace Atomic Absorption Spectrophotometer (AAS-Perkin Elmer model AAnalyst800, Massachusetts, USA) depending on the concentrations.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The standard stock solution (100 mg/L) of Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn was prepared from analytical grade metallic salts.The stock solutions were prepared with deionized water in 1 L volumetric flasks.

Test organisms (species):

other aquatic mollusc: Freshwater Snail, Melanoides tuberculata

Details on test organisms:

TEST ORGANISM
- Common name: Freshwater snail
- Strain/clone: Melanoides tuberculata
- Age at study initiation (mean and range, SD): adult snails
- Weight at study initiation (mean and range, SD): mean wet weight 22 . 5 ± 1.6 mg
- Length at study initiation (length definition, mean, range and SD): shell length approximately 1.5–2.0 cm
- Feeding during test : no

ACCLIMATION
- Acclimation period: Prior to toxicity testing, the snails were acclimatized for one week under laboratory conditions (28–30°C with 12 h light : 12 h
darkness) in 50-L stocking tanks using dechlorinated tap water (filtered by several layers of sand and activated carbon; T.C. Sediment Filter (TK Multitrade, Seri Kembangan, Malaysia)) aerated through an air stone. During acclimation the snails were fed on lettuce.
- Type and amount of food: lettuce

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

18.72 ± 1.72 mg/L

pH:

6.68 ± 0.22

Dissolved oxygen:

6.1 ± 0.27 mg/L

Conductivity:

180.0 ± 46.0 µS/cm

Nominal and measured concentrations:

10, 32, 56, 87, 100 mg/L nominal,
12.98, 31.60, 57.81, 85.61, 97.01 mg/L measured

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Material, size, headspace, fill volume: glass, 500 mL fill volume
- Volume of solution: 400 mL
- Renewal rate of test solution (frequency/flow rate): every two days
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Photoperiod: 12/12
- Light intensity: 334-376 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality

VEHICLE CONTROL PERFORMED: yes

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

120.43 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Mn2+

Basis for effect:

mortality

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

45.56 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Mn2+

Basis for effect:

mortality

Reported statistics and error estimates:

FORTRAN programs based on the methods of Litchfield and Litchfield and Wilcoxon were used to compute the LT 50 and LC 50 .

Validity criteria fulfilled:

not applicable

Conclusions:

In the present study of Shuhaimi-Othman et al.(2012) freshwater snails were exposed to five different concentration of MnSO4. Snails were incubated with nominal concentrations of 10, 32, 56, 87, and 100 mg/L Mn2+ for 96h under static condictions. The 96h LC50 value for Mn2+ in Melanoides tuberculata is 45.56 mg/L (corresponding to 187.6 mg manganese monoglycinate sulfate/L) the 48h LC50 is 120.43 mg/L (corresponding to 495.9 mg manganese monoglycinate sulfate/L).

Executive summary:

The 96-hr-acute toxicity of MnSO₄to Melanoides tuberculata was studied under static conditions.  Snails were exposed to control and test chemical at nominal concentrations of 10, 32, 56, 87, and 100 mg/L Mn²⁺(corresponding to 12.98, 31.60, 57.81, 85.61, 97.01 mg/L measured concentrations) in chlorinated tap water for 96 h.

Mortality was recorded every 3 to 4 hours for the first two days and then at 12 to 24 hour intervals throughout the rest of the test period. The criterion used to determine mortality were failure to respond to gentle physical stimulation. The death was further confirmed by putting the snail on the glass petri dish for few minutes and if it did not show any movement, it was considered dead.

Mortality/immobilization was observed daily. 

The 96-hour LC50 was 45.56 mg Mn²⁺/L which corresponds to 187.6 mg manganese monoglycinate sulfate/L.

 

This study is classified as acceptable as it was conducted according to generally accepted scientific principles and satisfies the requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

Test Organism Age: adult snails

Test Type: Static Renewal

 

LC50: 45.56 mg Mn²⁺/L

Endpoint(s) Effected:  mortality

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

Testing was performed according to ISO 6341: Daphnia magna was cultivated in the dilution water described in ISO 6341 in the temperature of 25 ± 2°C in the light rythm of 17h light and 7h dark. Daphnids were fed ad libitum with a pure culture of Celenastrum capricornutum. Acute toxicity was determined according to standards ISO 6341 and SFS 5062. The test temperature was 25 ± 2°C. For each test concentration, three replicates with five daphnids in each were studied. Test vials were kept in the daylight. According to the standards, a sensitivity check was done with potassium dichromate. EC50 values with 95% confidence limits were calculated by a probit analysis computer program, version 2.3. (National Swedish Environmental Protection Agency).

GLP compliance:

no

Analytical monitoring:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: From the chemicals, stock solutions containing 1000 mg/L of the metal were prepared in distilled water. EDTA stock solution contained 10 g EDTA/L. In the case of DTPA, a stock solution containing 100 g DTPA/L was prepared in the dilution water described in ISO 6341. To examine the effect of complexation, an equimolar amount of solid EDTA or DTPA was added to each metal stock solution. To make the final test solutions, mainly few hundreds of µL of the respective stock solution or a dilution ofit was used. Since the volumes were so small, there was no need for pH adjustment.
- Controls: destilled water (negative control) potassium dichromate (positive control)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia magna
- Method of breeding: Daphnia magna was cultivated in the dilution water described in ISO 6341
- Photoperiod: 17/7h

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

25 ± 2°C

Nominal and measured concentrations:

Not reported

Details on test conditions:

TEST SYSTEM
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dilution water as described in ISO 6341

OTHER TEST CONDITIONS
- Adjustment of pH: Not necessary
- Photoperiod: 17/7

Reference substance (positive control):

yes

Remarks:

dipotassium chromate

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Mn2+

Basis for effect:

mortality

Results with reference substance (positive control):

Sensitivity check with K2Cr2O7 gave an EC50 value of 0.34 mg/L, with a confidence interval between 0.21 and 0.47 mg/L. In ISO 6341, an acceptable range of 0.9 to 2.4 mg/L is given.

Reported statistics and error estimates:

EC50 values with 95% confidence limits were calculated by a probit analysis computer program, version 2.3. (National Swedish Environmental Protection Agency).

Validity criteria fulfilled:

not applicable

Conclusions:

In the present publication 15 Daphnids were exposed to MgSO4 x 7H2O dissolved in water at different concentrations. The 24h EC50 value was determined to be 56 mg Mn2+/L which corresponds to approximately 230 mg manganese monoglycinate sulfate/L.

Executive summary:

The 24-hr-acute toxicity of MnSO₄to Daphnia magna was studied.  Daphnids were exposed to control and test chemical at various concentrations of MnSO₄in dilution water for 24 h.

Immobilization was recorded at 24 hours. The criterion used to determine mortality were failure to respond to physical stimulation.

Mortality/immobilization was observed after 24h. 

The 24-hour EC50 was 56mg Mn²⁺/L which corresponds to 230 mg manganese monoglycinate sulfate/L.

 

This study is classified as acceptable as it was conducted according to generally accepted scientific principles and satisfies the requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

Test Organism Age: n/a

Test Type: n/a

 

EC50: 56mg Mn²⁺/L

Endpoint(s) Effected:  Immobilization

Description of key information

Biesinger and Christensen (1972): water flea (Daphnia magna) were exposed to concentrations of 5 and 10 mg/L MnCl₂for 48 h under static conditions. The LC50 was determined to be 9.8 mg Mn²⁺/L.

Martin and Holdich (1985): The toxicity of metal ions in Asellus aquaticus and Crangonyx pseudogracilils was determined after 48h and 96h under static conditions in at least 8 Mn^{2 +}concentrations. The 48h LC50 was determined as follows: 1389 ppm for Crangonyx pseudogracilils and the 96h LC50 was 694 ppm for Crangonyx pseudogracilils.

Sorvani and Sillanpää (1996): The 24h LC50 values of free divalent manganese ions and the respective EDTA/DTPA complex were determined in Daphnia magna. After 24h the EC50 value was 56 mg Mn²⁺/L (which corresponds to 230 mg manganese monoglycinate sulfate) for the free ions and increased for the respective EDTA complex (940 mg/L) and for the DTPA complex to 2300 mg/L.

Shuhaimi (2012): Freshwater snails Melanoides tuberculate were exposed to nominal 10, 32, 56, 87, 100 mg/L MnSO₄under static conditions for 96h. The LC50 value for 48 and 96h was determined to be 120.43 mg Mn²⁺/L and 45.56 mg Mn²⁺/L, respectively.

Research of the QSAR-Toolbox databases: Glycine was reported to be readily biodegradable as proved by a database entry generated from a study conducted according to OECD 301. QSAR predictions: EpiSuite, SciQSAR and Leadscope revealed a very low toxicity to aquatic invertebrates with the following EC50 values: EpiSuite: 32749.543 mg/L; SciQSAR: 1788.819 mg/L; Leadscope: 610.1076 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

230 mg/L

Additional information

There are no data for manganese monoglycinate sulfate regarding short term toxicity to aquatic invertebrates. However, the ecotoxicity of manganese monoglycinate sulfate was assessed based on a read-across approach. This read-across hypothesis is based on transformation of the target and source substances to common compounds (scenario1 of the RAAF). The target substance manganese monoglycinate sulfate and the source substances manganese sulfate, manganese Chloride, and other manganese compounds are ionic and consist of the Mn²⁺cation and the respective anion (glycine). For a more detailed explanation of the read-across hypothesis please refer to the general justification for read-across in section 13 of the IUCLID file.

Data are available for several Mn²⁺salts as well as for glycine.

In the study of Biesinger and Christensen (1972) water flea (Daphnia magna) were exposed to concentrations of 5 and 10 mg/L MnCl₂for 48 h under static conditions. The LC50 was determined to be 9.8 mg Mn²⁺/L.

In another study of Martin and Holdich (1985) the toxicity of metal ions towards crustaceans was determined in Asellus aquaticus and Crangonyx pseudogracilils after 48h and 96h under static conditions. At least eight Mn²⁺concentrations (from dissolved MnCl₂) were used in this test. The 48h LC50 was determined as follows: 1389 ppm for Crangonyx pseudogracilils and the 96h LC50 was 694 ppm for Crangonyx pseudogracilils.

In the study of Sorvani and Sillanpää the 24h LC50 of free divalent manganese ions and the respective EDTA/DTPA complex were determined in Daphnia magna. After 24h the EC50 value was 56 mg/L for the free ions and increased for the respective EDTA complex (940 mg/L) and for the DTPA complex to 2300 mg/L.

In the study of Shuhaimi (2012) freshwater snails Melanoides tuberculate were exposed to nominal 10, 32, 56, 87, 100 mg/L dissolved MnSO₄under static conditions for 96h. The LC50 value for 48 and 96h was determined to be 120.43 mg Mn²⁺/L and 45.56 mg Mn²⁺/L, respectively.

The other source substance glycine is also considered to be of very low toxicity to aquatic life based on its utilization in aquatic invertebrates and plants. This assumption is substantiated by a research of the QSAR-Toolbox databases. Glycine was reported to be readily biodegradable as proved by a database entry generated from a study conducted according to OECD 301. Furthermore, QSAR predictions performed with EpiSuite and the commercial software programs SciQSAR and Leadscope revealed a very low toxicity to aquatic invertebrates.

Based on the varying organisms that were used in the different studies and the different endpoints that were investigated, i.e. LC50 vs. EC50 values, the EC50 value for aquatic invertebrates was set to 56 mg Mn²⁺/L (which corresponds to 230 mg manganese monoglycinate sulfate) for precautionary reasons.

In the study of Sorvani and Sillanpää the 24h LC50 value of the source substance MnSO₄was determined in the recommended test organism Daphnia magna. The methods used were sufficiently described to judge this study as reliable. In the study of Biesinger and Christensen (1972) only two concentrations of MnCl₂were tested. Martin and Holdich (1985) used invertebrates that are not explicitly recommended for ecotoxicity testing. Furthermore, the results obtained from this study revealed higher LC50 values as compared to the other studies, thus Asellus aquaticus and Crangonyx pseudogracilils are less sensitive to metal toxicants. Similarly, the freshwater snail Melanoides tuberculate seems to be less sensitive to metal ions after 48h exposure, whereas after 96h exposure the LC50 value was in a similar range as the EC50 value for Daphnia magna. The other source substance glycine is an abundant occurring amino acid and can be found in virtually every living organism. It is generally accepted that glycine exhibits only a very low toxicity. The request of the QSAR-Toolbox databases and several reliable QSAR calculations substantiate this notion. Thus, in the target substance manganese monoglycinate sulfate the contained manganese is expected to be the main toxicant. Based on the provided results and the read-across hypothesis the EC50 value for aquatic invertebrates is set to 56 mg Mn²⁺/L, corresponding to 230 mg manganese monoglycinate sulfate/L.