Reaction products of sodium glucoheptonate with manganese sulfate and sodium hydroxide

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:

other: Similar to OECD Guideline 202 with restrictions, tested concentrations not given,translation from German report, but data indicate that study was well-performed.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

: tested concentrations not given

GLP compliance:

no

Specific details on test material used for the study:

No further details on properties of test surrogate or analogue material are given.

Analytical monitoring:

not specified

Vehicle:

not specified

Details on test solutions:

No details on test solutions are provided

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: German: Kleinkrebse
- Strain:Daphnia magna
- Source: In-House breeding from animals from unenclosed waters
- Age at study initiation (mean and range, SD): max. 24 h
- Feeding during test: unknown
- Food type, in general: Green algae, Scenedesmus

No details on acclimation or quarantine are given.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

no data

Hardness:

12°dH

Test temperature:

23°C

pH:

7,5

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

no data

Details on test conditions:

TEST SYSTEM
- Test vessel: Tube made of Geräteglas 20, 18 mm diameter, equipped with Kapsenberg seal

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

<= 50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: endpoint stated in this publication as "Ausgeprägte Schadwirkung", 50% or more animals affected

Validity criteria fulfilled:

not specified

Conclusions:

Based on the given data, the study can be considered as reliable with some restrictions and the intrinsic properties of the read-across substance MnCl2 allow reliable conclusions for manganese glucoheptonate.

Executive summary:

The 48 h acute toxicity of MnCl2 to Daphnia magna was studied under static conditions. Daphnids were exposed to MnCl2*4H2O for 48 h, immobilization was observed at the end of the study period. The 48 h LC50 was determined to be ≤ 50 mg/L. This study is classified as reliable with restrictions (Klimisch 2) and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1989

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:

Ten daphnids were exposed to each concentration, and each concentration was prepared in replicates of three. Tests were conducted in 200-ml beakers containing 100 ml of test water. The concentrations were given as milligrams per liter of metal ions. Test daphnids were presumed dead when there was complete immobilization (no heart beat) and no response to pressing with a blunt glass rod. Death was further confirmed by transferring daphnids back to fresh control tubewell water. The dead specimens were removed and recorded at intervals of 30 min and 1,2,4, 8, 14 + 2, 24, 33 + 3, and 48h.

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

Stock solutions were prepared in distilled water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone:
- Justification for species other than prescribed by test guideline:
- Source: obtained from natural pond situated at Gheru Campus of the Industrial Research Centre, Lucknow
- Feeding during test: no, just during culture period
- Food type: food consisted of a 1000 mg/L suspension of dry fish food (Shalimar FIsh Food Co., Bombay) and yeast.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

240 mg CaCO3/L

Test temperature:

13 °C

pH:

7.2 - 7.8

Dissolved oxygen:

5.2 - 6.5 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 200 ml beakers
- fill volume: 100 ml
- Aeration: yes
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): not specified

TEST MEDIUM / WATER PARAMETERS
- Tubewell
- Chlorine: 5 -10 mg/L
- Alkalinity: 390 - 415 mg/L as CaCO3

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

10 mg/L

Conc. based on:

element

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8.28 mg/L

Conc. based on:

element

Basis for effect:

mortality

Conclusions:

The reported 24h and 48 h EC50 values for MnSO4 to daphnids were 10.0 and 8.28 mg Mn/L, respectively.

Executive summary:

Khangarot and Ray (1989) studied the acute toxicity of 23 metal ions to Daphnia magna in filtered aerated tubewell hard water (hardness; 240 mg CaCO3/L). The lethal concentrations (EC50) were determined by the immobilization test. Test daphnid were presumed dead when there was complete immobilization (no heart beat) and no response to pressing with a blunt glass rod. Death was further confirmed by transferring daphnids back to fresh control tubewell water.

The reported 24h and 48h EC50 values for MnSO4 to daphnids were 10.0 and 8.28 mg Mn/L, respectively.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1972

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Principles of method if other than guideline:

For acute tests, 10 daphnids 12 +/- 12 h old were placed in duplicate test chambers and subjected to test conditions for 2 days (48 hr). Tests were run both with and without food additions as the food changed the toxicity values. Complete immobilization or death
was the endpoint.

GLP compliance:

no

Specific details on test material used for the study:

An American Chemical Society reagent-grade chemical was used for all tesings.

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: from a laboratory clone originally obtained from the University of Michigan
- Feeding during test: They were fed a suspension of food (1 ml/liter) twtce
weekly for rearing and once weekly for testing.
- Feeding information: 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 boltine 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.

Test type:

not specified

Water media type:

freshwater

Remarks:

Lake Superior water

Limit test:

no

Total exposure duration:

48 h

Hardness:

44000 - 53000 µg/L

pH:

7.4 - 8.2

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

9 800 µg/L

Conc. based on:

element

Remarks on result:

other: without feeding during test

Conclusions:

The reported 48h LC50 is 9800 µg/L and is based on the metal ion.

Executive summary:

The acute toxicity of various metal ions to Daphnia magna was tested by Biesinger and Christensen (1972). As a test medium, Lake Superior water was used. Manganese was added to the test system as MnCl2*4H2O. The reported 48h LC50 is 9800 µg/L (= 9.8 mg/L) and is based on the metal ion.

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:

other: Similar to guideline study, non-standard species, prolonged test duration, minor deficiencies in documentation. However, the given data indicate that the study was well-performed.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Nitocra spinipes was used instead of daphnids, test duration was 96h, ten animals were tested in one vessel

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Nitocra spinipes

Details on test organisms:

TEST ORGANISM
- Common name: Harpacticoid Copepod
- Strain: Nitocra spinipes Boeck
- Source: static brackish water aquarium with prawns
- Age at study initiation (mean and range, SD): adult, at least 7 - 10 days
- Length at study initiation (length definition, mean, range and SD): 0.7 - 0.8 mm
- Method of breeding: 20 ovigerous females (females with egg-sac) were pipetted and isolated one by one in dishes with brackish water (7‰ salinity). To select the most tolerant laboratory animal, the offspring from the individual females was cultivated to a number of about 30-100 animals which were exposed to a wide range of temperatures and salinities. After about 4 weeks, the offspring of 2 of the original 20 females had demonstrated a superior tolerance to the offered laboratory conditions. Stock culture in open 100 ml crystallizing dishes.
- Feeding during test: no
- Food type: finely ground salmon food (Ewos 2, Astra-Ewos, Södertälje, Sweden).

Test type:

static

Water media type:

brackish water

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no data

Hardness:

no data

Test temperature:

20 ± 0.5 °C

pH:

8.0

Dissolved oxygen:

no data

Salinity:

7 ‰

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tube
- Material, size, headspace, fill volume: 10 or 15 ml fill volume
- No. of organisms per vessel: 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: brackish water, which had first been filtered through a 30/µm filter, heated to 80°C, filtered again through folded paper filter and conditioned to room temperature. The temperature was held constant at 20+0.5°C during the experiment by submerging the rack of test tubes into a water bath regulated by a thermostat.
- Alkalinity: 1.5 meqv / l

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

TEST CONCENTRATIONS
- Spacing factor for test concentrations: narrow intervals
- Test concentrations: ten different concentrations

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

70 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Mn2+

Basis for effect:

mortality

Remarks:

determined from movement

Remarks on result:

other: 95 % confidence limits: 52 - 94 mg/L

Reported statistics and error estimates:

Estimation of the 96 h LC50-value according to the method described by Litchfield & Wilcoxon (1949), including 95% confidence limits.

Validity criteria fulfilled:

not specified

Conclusions:

The present study was performed similar to OECD Guideline 202. Although it was performed on the non-standard species Nitocra spinipes, which serves as a perfectly suitable surrogate, the given data indicate that the study was well-performed and therefore, the results can considered to be reliable and used for classification. The LC50 value after 96 h was determined to be 70 mg/L Mn2+.

Executive summary:

The 96 h acute toxicity test of MnCl₂ to Nitocra spinipes Boeck was studied under static conditions and performed similar to OECD guideline 202 with minor deviations. Copepods were exposed to Manganese at ten different nominal concentrations for 96 h. Mortality (derived from immobilization) was observed at test termination. The LC50 (96 h) of the Manganese cation was 70 mg/L. This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

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:

other: not standard species Daphnia; However, the given data indicate that the study was well performed and meets general scientific principles and requirements.

Qualifier:

according to guideline

Guideline:

other: APHA, AWWA, WPCF (1981) Standard methods for the examination of water and waste waters.

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on sampling:

not applicable

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): deionized water

Test organisms (species):

other aquatic worm: Tubifex tubifex (Muller)

Details on test organisms:

TEST ORGANISM
- Common name: Tubificid worm
- Strain: Tubifex tubifex Muller
- Source: collected from Gheru Campus of ITRC, Lucknow
- Method of breeding: not applicable
- Feeding during test: no data

ACCLIMATION
- Acclimation period: 7 days

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Remarks on exposure duration:

Dead specimens were removed and recorded at intervals of 30 min and 1, 2, 4, 8, 14±2, 24, 33+3, 48 and 96h.

Post exposure observation period:

no data

Hardness:

Total hardness 245 mg/L as CaCO3 (range 230-250mg/L)

Test temperature:

30°C (range 29.5-31°C)

pH:

7.6 (7.5-7.7)

Dissolved oxygen:

5.8 mg/L (range 5.2-6.0)

Salinity:

Total alkalinity 400 mg/L as CaCO3 (range 390-410 mg/L)
Calcium 160 mg/ L (range 151-167 mg/L)
Magnesium 90 mg/ L (range 80-98 mg/L)
Chloride 10 mg/ L (range 7-12 mg/L)

Details on test conditions:

TEST SYSTEM
- Test vessel: 200 ml beakers
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, 200 ml
- Aeration: open vessel, i.e. passive oxygen diffusion
- Renewal rate of test solution (frequency/flow rate): every 24 h at once
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tubewell
- Chlorine: 10 mg/ L (range 7-12 mg/L)
- Ca/Mg ratio: 16/9

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations: logarithmic scale
- Range finding study: yes
- Test concentrations: based on the results of preliminary acute static bioassays

Reference substance (positive control):

not specified

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

301.3 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Mn

Basis for effect:

mortality

Remarks on result:

other: 95% confidence interval 264.93 - 350.81 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

208.06 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Mn

Basis for effect:

mortality

Remarks on result:

other: 95% confidence interval 248.16 - 335.71 mg/L

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

170.61 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Mn

Basis for effect:

mortality

Remarks on result:

other: 95% confidence interval 147.17 - 197.76 mg/L

Details on results:

no data

Reported statistics and error estimates:

Effect concentrations were determined as mean values and 95% confidence limits were calculated by the moving average angle method.

Validity criteria fulfilled:

yes

Remarks:

The dissolved oxygen concentration was greater than 3 mg/L, no data on control were given.

Conclusions:

The present study was performed similar to standard recommendations APHA, AWWA, WPCF (1981, Standard methods for the examination of water and waste waters). Although it was performed on the non-standard species Tubifex tubifex, the given data indicate that the study was well-performed and therefore, the results can be considered reliable and used for classification. Additionally, Tubifex tubifex is also a relevant species in the food chain, which makes the examination of the effects of a chemical sustance in this species in general scientifically justified, too. The EC50 values of all regarded endpoints are greater than 100 mg Mn/L. Consequently, MnSO4 can considered to be non-harmful for aquatic life.

Executive summary:

The 24, 48 and 96h acute toxicity test of MnSO₄*2H₂O to Tubifex tubifex was studied under semi-static conditions and performed according APHA, AWWA, WPCF (1981, Standard methods for the examination of water and waste waters). Tubificid worms were exposed to several concentrations of MnSO₄*2H₂O (referring to metal) for up to 96h. Mortality / immobilization were observed at intervals of 30 min and 1, 2, 4, 8, 14±2, 24, 33±3, 48 and 96h. The 24, 48 and 96h EC₅₀ were 301.3 mg/L, 208.6 mg/L and 170.61 mg/L, respectively.

Reference 6

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2000

Reliability:

2 (reliable with restrictions)

Qualifier:

no guideline followed

Principles of method if other than guideline:

Three differents tests were conducted, thereby, Hyalella azteca were exposed in 96h static tests. Five replicates were used per treatment, each consisting of 30 ml plastic cup containing 20 ml of
solution, a 1.5-cm2 piece of Nitext netting, and 10 animals. The samples were maintained at 23 °C with a 16h light: 8h dark photoperiod. H. azteca were not fed during the test.
Ceriodaphnia dubia were exposed in acute 48h and chronic 7 day tests (US EPA 1993a, 1994b). Acute tests with C. dubia were static exposures in which the animals were not fed. In chronic tests, animals were transferred daily into 15 mL of fresh test solution that had received 0.1 ml of YCT and 0.1 ml of S. capricornutum.
The tests weith C. dubia were done with two age groups of C. dubia where the first age group was < 24h old and the second age group was 24 to 48h old.
For both test species, different waters were used as test medium representing different hardnesses.

GLP compliance:

no

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Each of the different waters was used for the preparation of the highest MnCL2 concentration and was also used for the dilution of the stock solution.

Test organisms (species):

other: Ceriodaphnia dubia and Hylella azteca

Details on test organisms:

Two ages of C. dubia neonates (<24 h old and 24 to 48 h old) were compared to determine if their sensitivities to Mn differed. On the day before test initiation, C. dubia neonates ,24 h old were obtained from in-house cultures utilizing moderately hard water. Neonates were transferred into MH4 water and fed 10 ml Selenastrum capricornutum (3 x 10^7 cells/mL) per liter and 5 ml of a yeast-cerophyl-trout chow (YCT) combination (US EPA 1994b) per liter. On the day of test initiation, another batch of <24-h-old neonates were harvested and held for several hours in MH4 water with the same amounts of food.

Known-age H. azteca were obtained for testing from in-house cultures using methods similar to those of Tomasovic et al. (1995). Mixed-aged animals from the cultures were placed on 1-mm mesh sieves and gently agitated. Animals retained on the sieves were transferred to 355-μm mesh sieves in 8-L plastic containers with 6 L of MH5 water. Water in the containers was continually aerated, and the sieves angled with one side elevated to facilitate water circulation. A small amount of Tetrafint was added to the sieves for food. After 24 h, the sieves were again agitated and transferred to a container with 6 L of fresh water to which 45 ml of S. capricornutum algae and 25 ml of YCT had been added as food for the young animals. The sieves were agitated and removed 24 h later, leaving the <24-h-old animals in the 6 L of water. Approximately 500 adult animals placed on each sieve produced around 600 young in 24 h. The young H. azteca were held for 6 days with water exchanged (60%) every other day, at which time additional food was added at the above rates.

Test type:

static

Water media type:

freshwater

Limit test:

no

Remarks on exposure duration:

With H. azteca 96-h static tests were done. C. dubia was exposure to Mn in 48-h and 7-d static tests.

Hardness:

Various hardnesses were used as test medium.

pH:

varied between 8.0 (soft water) - 8.4 (hard water):
- SW: pH 8.0
- MH4: pH 8.1
- H4: pH 8.2
- MH5: pH 8.3
- H5: pH 8.4

Duration:

96 h

Dose descriptor:

LC50

Remarks:

Hyalella azteca

Effect conc.:

> 3 - < 13.7 mg/L

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other:

Remarks:

LC50 depending on water hardness

Duration:

48 h

Dose descriptor:

LC50

Remarks:

Ceriodaphnia dubia (both age groups)

Effect conc.:

> 5.7 - < 6.7 mg/L

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other: soft water (SW)

Duration:

48 h

Dose descriptor:

LC50

Remarks:

Ceriodaphnia dubia (both age groups)

Effect conc.:

14.5 mg/L

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other: moderately hard water (MH4)

Duration:

48 h

Dose descriptor:

LC50

Remarks:

Ceriodaphnia dubia (both age groups)

Effect conc.:

> 14.5 - < 15.9 mg/L

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other: hard water (H4)

Duration:

7 d

Dose descriptor:

IC50

Remarks:

Ceriodaphnia dubia (both age groups)

Effect conc.:

3.9 mg/L

Conc. based on:

element

Basis for effect:

other: number of young per female and number of broods per female)

Remarks on result:

other: soft water (SW)

Duration:

7 d

Dose descriptor:

IC50

Remarks:

Ceriodaphnia dubia (both age groups)

Effect conc.:

> 8.1 - < 9 mg/L

Conc. based on:

element

Basis for effect:

other: number of young per female and number of broods per female)

Remarks on result:

other: moderately hard water (MH4)

Duration:

7 d

Dose descriptor:

IC50

Remarks:

Ceriodaphnia dubia (both age groups)

Effect conc.:

> 11.4 - < 11.6 mg/L

Conc. based on:

element

Basis for effect:

other: number of young per female and number of broods per female)

Remarks on result:

other: hard water (H4)

Executive summary:

Manganese was toxic to H. azteca and C. dubia and increased water hardness significantly reduced toxicity (please see figures 1 and 2). For H. azteca, the 96h LC50 ranged from 3.0 (soft water) to 13.7 mg/l (hard water). C. dubia showed higher sensitivity to Mn in soft hard water (mean: 6.2 mg/L) than in moderately hard and hard waters (MH4: 14.5 mg/L; H4: mean: 15.2 mg/L). In general C. dubia demonstrated less sensitivity to Mn in soft and moderately hard waters than H. azteca but roughly the same tolerance in hard water. Meyer et al (1994) stated, that the hardness cations, Ca and Mg, can have a competitive effect with respect to the toxicity of divalent metals, including Mn.

For C. dubia, two ages were tested (<24 h or 24 to 48 h) but the sensitivity of C. dubia was not significantly affect by Mn (Figure 2) within the 48h acute toxicity and the 7-d toxicity test. Both ages of C. dubia reared in MH4 produced significantly (alpha = 0.05) greater numbers of neonates per female than those reared in SW. The mean obtained 7-d IC50s for both age groups are 3.9 mg/L (soft water), 8.55 mg/L (moderately hard water) and 11.5 mg/L (hard water).

Reference 7

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:

other: not all details documented. The test was conducted according standard recommendations (APHA 1989) and the given data indicate that the study was well performed.

Qualifier:

according to guideline

Guideline:

other: APHA 1989

GLP compliance:

not specified

Specific details on test material used for the study:

no data

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Tests concentrations were prepared by diluting appropriate aliquots of the stock solution with test water 1 h before the addition of tubficid worms
- Controls: yes, no test substance
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): double-glass distilled water.
- Concentration of vehicle in test medium (stock solution and final test solution): not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no data

Test organisms (species):

other aquatic worm: Tubifex tubifex

Details on test organisms:

TEST ORGANISM
- Common name: Tubificid worm
- Strain: Tubifex tubifex Müller

ACCLIMATION
- Acclimation period: 48 - 96 h

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

237 mg/L as CaCO3 (range: 226 - 255 mg/L)

Test temperature:

15 - 30 ° C
Four different test series were performed at 15, 20, 25 and 30 °C with a deviation of each ± 1 °C

pH:

7.5 (range: 7.3 - 7.8)

Dissolved oxygen:

5.7 mg/L (range: 5.1 - 6.5 mg/L)

Nominal and measured concentrations:

Nominal: 0, 56, 100, 180, 320, 560 mg/L referring to the metal ion

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker / environmental growth chambers maintained at the appropriate temperature
- Type (delete if not applicable): no data
- Material, size, headspace, fill volume: no data
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- Renewal rate of test solution (frequency/flow rate): no
- No. of organisms per vessel: no data
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ground well water
- Total solids: 870 mg/L (range: 810 - 1150 mg/L)
- Metals: no data
- Pesticides: no data
- Chlorine: no data
- Alkalinity: 380 mg/L as CaCO3 (range (360 - 415 mg/L)
- Ca/Mg ratio: 165/94
- Conductivity: 950 µohm/cm (range: 800 - 1000 µohm/cm)
- Culture medium different from test medium: no data
- Intervals of water quality measurement: according standard procedures (APHA 1989)

OTHER TEST CONDITIONS
- Photoperiod: 12 h light / 12 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality, sub-lethal effects (not quantifiyable)

TEST CONCENTRATIONS
- Test concentrations: 0, 56, 100, 180, 320, 560 mg/L referring to the metal ion (nominal)

Reference substance (positive control):

not specified

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

422.36 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Mn

Basis for effect:

mortality

Remarks:

at 20°C

Remarks on result:

other: 361.47 - 495.59 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

350.16 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Mn

Basis for effect:

mortality

Remarks:

at 20°C

Remarks on result:

other: 291.91-406.77 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

275.7 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Mn

Basis for effect:

mortality

Remarks:

at 20°C

Remarks on result:

other: 235.99-329.49 mg/L

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

275.7 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Mn

Basis for effect:

mortality

Remarks:

at 20°C

Remarks on result:

other: 235.99-329.49 mg/L

Details on results:

- Mortality of control: all control worms survived and remained healthy with normal behavior during the tests

Reported statistics and error estimates:

The EC values and 95% confidence limits were calculated using the moving-average-angle method (Harris, E. K. (1959). Confidence limits for LD50 using the moving-average-angle method. Biometries 15, 424-432.).

Table 1: Percentage Mortality at 48 and 96 h of Exposure in Tubifex tubifex at Different Temperatures

Concentration Mn^2+(mg/L)	Percentage mortality at different temperatures
	15 °C		20 °C		25 °C		30 °C
	48 h	96 h	48 h	96 h	48 h	96 h	48 h	96 h
560	100	100	100	100	100	100	90	100
320	100	100	30	80	70	100	80	100
180	60	70	0	0	0	0	0	0
100	0	0	0	0	0	0	0	0
56	0	0	0	0	0	0	0	0
Control	0	0	0	0	0	0	0	0

 

Table 2: EC₅₀values and 95% Confidence limits of Manganese at different temperatures

Temperature	LC50 values and 95% confidence limits (mg/L)
	24 h	48 h	72 h	96 h
15 °C	179.70 (152.76-220.16)	171.41 (147.25-210.42)	171.41 (147.25-210.42)	164.55 (140.28-198.76)
20 °C	422.36 (361.47-495.59)	350.16 (291.91-406.77)	275.7 (235.99-329.49)	275.70 (235.99-329.49)
25 °C	319.50 (272.51-389.78)	293.08 (250.69-352.64)	293.08 (250.69-352.64)	239.27 (204.02-283.38)
30 °C	567.03 (472.60-653.48)	294.26 (244.71-364.61)	273.02 (228.84-341.16)	239.39 (204.04-281.79)

Validity criteria fulfilled:

yes

Remarks:

Referring to validity criteria for Daphnia: In the control, not more than 10 % of the worms were immobilized, oxygen content was always > 3 mg/L

Conclusions:

The present study was performed similar to standard recommendations according to APHA (1989). Although it was performed on the non-standard species Tubifex tubifex, the given data indicate that the study was well-performed and therefore, the results can be considered reliable and used for classification. Additionally, Tubifex tubifex is also a relevant species in the food chain, which makes the examination of the effects of a chemical sustance in this species in general scientifically justified.
The present study was performed at four different temperatures in order to simulate the conditions in Indian lakes with widely fluctuant temperatures more precisely. As most standard guidelines (which are strongly recommended to be followed for studies for REACH purposes) specify a standard temperature of 18-22°C, the observed EC50 values at 20°C are considered to be the relevant ones to assess the effects of Manganese on this species.
The EC50 values of all regarded endpoints, i.e. 24-96 h, are greater than 100 mg Mn/L. Consequently, MnSO4 can be considered to be non-harmful for aquatic life.

Executive summary:

The 24, 48 and 96 h acute toxicity test of MnSO₄*H₂O to Tubifex tubifex was studied under static conditions and performed according to APHA (1989). Tubificid worms were exposed to several concentrations of MnSO₄*H₂O (referring to metal) for up to 96 h at temperatures of 15, 20, 25 and 30 °C. Mortality / immobilization were observed regularly. The 24, 48, 72 and 96 h EC₅₀values at 20 °C were 422.36 mg/L, 350.16 mg/L, 275.7 mg/L and 275.70 mg/L, respectively.

Based on the results of this study, MnSO₄ would not have to be classified as harmful for aquatic life in accordance with the classification system under regulation 1272/2008/EC.

Reference 8

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:

other: see 'Remark'

Remarks:

No standard duration (7d), no standard species (Carinogammarus Roeselii, Tubifex tubifex, Chironomus thummi larvae, Anabolia nervosa larvae), no raw data listed, translation from German report. However, the given information indicate that the tests were well performed.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Invertebrate species (Carinogammarus Roeseli, Tubifex tubifex, Chironomus thummi larvae, Anabolia nervosa larvae) are exposed to the test substance at a range of concentrations for a period of 7 days. Immobilisation is recorded at the end of the exposure period. The results are given as "Letalitätsgrenze" (LC100) and "Schädlichkeitsgrenze" (LC0)

GLP compliance:

no

Specific details on test material used for the study:

No further datails given.

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

The manganese salt was directly added to Munich tap water, concentrations were calculated as mg/l metal. Prior to salt addition, water was softened by neutralisation with the corresponding amount of acid, i.e. 17.4 ml HCl conc. per 40 L water.

Test organisms (species):

other: Carinogammarus Roeselii, Tubifex tubifex, Chironomus thummi larvae, Anabolia nervosa larvae

Details on test organisms:

TEST ORGANISMS

Carinogammarus Roeselii (beach flea, German: Flohkrebs)
Tubifex tubifex (red sludge worm, German: roter Schlammröhrenwurm)
Chironomus thummi larvae (gnat larvae, German: Zuckmückelarven)
Anabolia nervosa larvae (Daddisfly larvae, German: Köcherfliegenlarven)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Post exposure observation period:

no data

Hardness:

14,8° dH

Test temperature:

18-20°C

pH:

neutralized, exact value not given

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

no data

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml petri dish

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Munich tap water

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Movement after mechanical stimulation

Chemism of aerated test solution was permanently monitored.

Reference substance (positive control):

not required

Duration:

7 d

Dose descriptor:

LC0

Remarks:

Carinogammarus Roeselii

Effect conc.:

15 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC100

Remarks:

Carinogammarus Roeselii

Effect conc.:

70 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC0

Remarks:

Tubifex tubifex

Effect conc.:

200 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC100

Remarks:

Tubifex tubifex

Effect conc.:

700 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC0

Remarks:

Anabolia nervosa larvae

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC100

Remarks:

Anabolia nervosa larvae

Effect conc.:

2 000 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC0

Remarks:

Chironomus thummi larvae

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC100

Remarks:

Chironomus thummi larvae

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

mortality

Validity criteria fulfilled:

not specified

Conclusions:

The standard duration of this test (48h, OECD guideline 202) is much shorter than the actual duration of 7 d and the given concentrations regard the metal only.

Executive summary:

The 7 d toxicity test of Mn2+ to Carinogammarus Roeselii, Tubifex tubifex, Chironomus thummi larvae and Anabolia nervosa larvae was performed by exposing the animals to Manganese. The 7 d LC0 values of the Manganese cation were 15, 200, 250 and 1000 mg/L, the 7 d LC100 values were 70, 700, 1000 and 2000 mg/L.

Reference 9

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:

other: study conducted according to OECD guidelines; quality assurance and GLP certificates.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

not specified

Specific details on test material used for the study:

No details given.

Analytical monitoring:

yes

Details on sampling:

No details given.

Vehicle:

not specified

Details on test solutions:

No details given.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: National Institute for Environmental Studies, Japan
- Age and gender: female juvenile (less than 24 hours)

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No details given.

Hardness:

No details given.

Test temperature:

20 +/- 1°C

pH:

No details given.

Dissolved oxygen:

≥ 60% of the saturation

Salinity:

Not applicable.

Nominal and measured concentrations:

Measured concentrations of the test substance in the test solution were within +/- 20% of the nominal concentration in all concentrations.

Details on test conditions:

TEST SYSTEM
- No. of vessels/concentration: 2 (range-finding test)
- Biomass loading rate: 10 daphnids/concentration (range-finding test)

OTHER TEST CONDITIONS
- Photoperiod: fluorescent light, 16 hours light (below 800 lux)/8 hours dark

TEST CONCENTRATIONS
- Range finding study
- Results used to determine the conditions for the definitive study: yes

TEST MEDIUM
- Dilution water (Elendt M4) recommended by OECD guidelines for testing of chemicals No. 211 was used.

Reference substance (positive control):

not required

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

not specified

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

not specified

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

not specified

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

not specified

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

not specified

Details on results:

No details given.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

No details given.

Validity criteria fulfilled:

not specified

Remarks:

immobilised daphnids in the control not reported

Conclusions:

EC50/NOEC (48 h) > 1000 mg/L (based on nominal concentration)

Executive summary:

The acute toxicity of Sodium gluconate (CAS 527-07-1) towards Daphnia magna has been determined according to OECD Guideline 202 in compliance with GLP. After the range-finding study (2 vessels/concentration, 10 daphnids/concentration), the definitive test was conducted with test concentrations of 0 (control) and 1000 mg/L (limit test). The measured concentrations of the test substance in the test solution were within +/- 20% of the nominal concentration in all concentrations (HPLC technique has been used).

The EC50/NOEC (48 h) value amounts to > 1000 mg/L based on the nominal test concentration.

Reference 10

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:

other: study conducted according to OECD guidelines; quality assurance and GLP certificates.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

No details given.

Analytical monitoring:

yes

Details on sampling:

No details given.

Vehicle:

not specified

Details on test solutions:

A limit test with 1000 mg/L was conducted: a solution of 100.5 mg in 100 mL or 1005 mg/L was prepared and distributed to 4 beakers.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain and source: Daphnia magna Straus origin from a clone breeding of the German Federal Environmental Agency, department V 3.2. 
- Age at study initiation: 2-23 h; Before using, the new young Daphnia were held at 20°C for 2 hours to ensure that none of them was younger than 2 h.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No details given.

Hardness:

No details given.

Test temperature:

Temperature in the incubator was stable at 20°C during the test period.

pH:

pH difference between beginning and end of test = 0.2 units.

Dissolved oxygen:

Oxygen concentration was 95% of the start concentration. 

Salinity:

Not applicable.

Nominal and measured concentrations:

The stability of the investigated concentration of sodium D-gluconate during testing was also examined via enzymatic analysis.  The test concentration did not decrease during the test period.

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- No. of organisms per vessel: 5

OTHER TEST CONDITIONS
- Light intensity: complete darkness for 48 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- After 24 and 48 h, the swimming capability of the daphnia was observed.  An animal not swimming within 15 seconds after gently moving the beaker was considered immobile. After 48 h, the oxygen concentration and the pH was measured.

TEST CONCENTRATIONS
- Test concentrations: 0 (control) and 1000 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

> 1 000 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

> 1 000 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No details given.

Results with reference substance (positive control):

Quality Assurance takes place in regular intervals using a concentration range of Potassium dichromate.  Last quality check was January 2001 and EC50 was between 1.16and 2.32 mg/L (required: 0.6-2.4 mg/L).

Reported statistics and error estimates:

No details given.

At 1000 mg/L, all daphnia kept their swimming capability.

Validity criteria fulfilled:

not specified

Remarks:

immobilised daphnids in the control not reported

Conclusions:

EC0 (48h) > 1000 mg/L

Executive summary:

The acute toxicity of Sodium gluconate (CAS 527-07-1) towards Daphnia magna was determined according to OECD Guideline 202 in compliance with GLP. A limit test with 1000 mg/L was conducted. The test organisms (5 daphnids/vessel) were exposed for 48 h to the test substance. The EC0 (48 h) based on mobility was determined to be > 1000 mg/L. Toxic effects were not observed.

Description of key information

There is no data available for the target substance manganese glucoheptonate on acute toxicity towards aquatic invertebrates. However, there is data available for the source substances sodium gluconate, manganese sulfate and manganese chloride. This data is used within a frame of a weight-of-evidence approach to assess the toxicity of manganese glucoheptonate.

The studies with the standard test organism Daphnia magna conducted by Bringmann (1959) as well as Khangarot and Ray (1989) are similar to OCED Guideline 202. Both results are similar and in agreement with the findings of Biesinger and Christensen (1972) who used Daphnia magna as test organism, too. Consequently, the key value for chemical safety assessment for freshwater invertebrates is set to the lowest reported 48h EC50 value for Daphnia manga: 64.4 mg/L (Khangerot and Ray, 1989) (please refer also to 'Additional information').

EC50(48h): 64.4 mg/L for Daphnia magna (Khangarot and Ray, 1989).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

64.4 mg/L

Additional information

sodium gluconate

The acute toxicity of the source substance Sodium gluconate (CAS 527-07-1) towards Daphnia magna has been determined according to OECD Guideline 202 in compliance with GLP (OECD SIDS, 2004). After the range-finding study (2 vessels/concentration, 10 daphnids/concentration), the definitive test was conducted with test concentrations of 0 (control) and 1000 mg/L (limit test). The measured concentrations of the test substance in the test solution were within +/- 20% of the nominal concentration in all concentrations (HPLC technique has been used). The EC50/NOEC (48h) value amounts to >1000 mg/L based on the nominal test concentration.

In addition, a limit test with 1000 mg/L was conducted. The test organisms (5 daphnids/vessel) were exposed for 48 h to the test substance. Th EC50 (48h) value based on mobility was determined to be >1000 mg/L. Toxic effects were not observed.

manganese compounds

The effect concentrations and lethal concentrations of manganese was determined for manganese compounds like MnSO4 and MnCl2 for a variety of invertebrate species. The studied species found in literature are comprised of Daphnia magna, Tubifex tubifex, Carinogammarus roeselii, Chironomus thummy larvae, Anabolia nervosa larvae, Ceriodaphnia dubia, Hyalella azteca, and Nitocra spinipes. The EC50, LC0, LC50 and LC100 found in literature were converted to corresponding values of the target substance manganese glucoheptonate (please see Table 1 in for a summary of calculated LC- and EC-values for manganese glucoheptonate). Thereby, it is assumed that no toxicity is attributed to the glucoheptonate as well as the possibly present anion (Cl2(2 -)or SO4(2 -)), that the absorption of manganese from this manganese compounds is 100 % and all manganese became systemically available. 

 

Bringmann (1959) used Daphnia magna, which is a standard test species for invertebrates, as test organism. The study was similar to OECD Guideline 202 with restrictions. Bringmann (1959) studied the 48h acute toxicity of MnCl2 to Daphnia magna under static conditions. Daphnids were exposed to MnCl2*4H2O for 48h, immobilization was observed at the end of the study period. The LC50 (48 h) was determined to be ≤ 50 mg/L. This study is classified as reliable with restrictions (Klimisch 2) and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

The data on MnCl2*4H2O allows estimating a corresponding 48h LC50 for manganese glucoheptonate. The 48h LC50 for manganese glucoheptonate is ≤108.0 mg/L for Daphnia magna.

Khangarot and Ray (1989) studied the acute toxicity of 23 metal ions to Daphnia magna in filtered aerated tubewell hard water (hardness; 240 mg CaCO3/L). The lethal concentrations (EC50) were determined by the immobilization test. Test daphnid were presumed dead when there was complete immobilization (no heart beat) and no response to pressing with a blunt glass rod. Death was further confirmed by transferring daphnids back to fresh control tubewell water. The reported 24h and 48h EC50 values for MnSO4 to daphnids were 10.0 and 8.28 mg Mn/L, respectively.

The corresponding 24h and the 48h EC50 describing the toxicity of manganese glucoheptonate to Daphnia magna are 77.8 mg/L and 64.4 mg/L, respectively.

 

The acute toxicity of various metal ions to Daphnia magna was also tested by Biesinger and Christensen (1972). As a test medium, Lake Superior water was used. Manganese was added to the test system as MnCl2*4H2O. The reported 48h LC50 is 9800 µg/L (= 9.8 mg/L) and is based on the metal ion.

The 48h LC50 for manganese glucoheptonate toxicity to Daphnia magna is 76.2 mg/L.

 

The 96h acute toxicity test of MnCl2 to Nitocra spinipes Boeckwas was studied under static conditions and performed similar to OECD guideline 202 with minor deviations (Bengtsson, 1978). Copepods were exposed to manganese at ten different nominal concentrations for 96h. Mortality (derived from immobilization) was observed at test termination. The 96h LC50 value of the manganese cation was 70 mg/L. This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

The 96h LC50 of MnCl2 can be used to calculate the corresponding 96h LC50 for manganese glucoheptonate. The 96h LC50 for manganese glucoheptonate is 544.5 mg/L for Nitrocra spinipes.

A 7 d toxicity test of Mn2+ to various species was performed by Schweiger (1956). The test was performed by exposing Carinogammarus roeselii, Tubifex tubifex, Chironomus thummi larvae and Anabolia nervosa larvae to manganese. The 7 d LC0 values of the Manganese cation were 15, 200, 250 and 1000 mg/L, the 7 d LC100 values were 70, 700, 1000 and 2000 mg/L, respectively.

The 7d LC0 and 7d LC100 for manganese glucoheptonate can be calculated, thereby, the 7d LC0 range from 116.7 mg/L (Carinogammarus roeselii) to 7778.4 mg/L (Anabolia nervosa larvae). The range of the 7d LC100 goes from 544.4 mg/L (Carinogammarus roeselii) to 15556.7 mg/L (Anabolia nervosa larvae). In this study, Carinogammarus roeselii is the most sensitive species for manganese glucoheptonate induced toxicity, whereas Anabolia nervosa larvae is the least influenced species. The 7d LC0 and 7d LC100 for Chironomus thummy larvae are 1944.6 and 7778.4 mg/L respectively. The 7d LC0 and 7d LC100 for Tubifex tubifex are 1555.7 and 5444.8 mg/L respectively. 

 

The 24, 48 and 96h acute toxicity test of MnSO4*2H2O to Tubifex tubifex was studied under semi-static conditions and performed according APHA, AWWA, WPCF (1981, Standard methods for the examination of water and waste waters) (Khangarot, 1991). Tubificid worms were exposed to several concentrations of MnSO4*2H2O (referring to metal) for up to 96h. Mortality / immobilization were observed at intervals of 30 min and 1, 2, 4, 8, 14±2, 24, 33±3, 48 and 96h. The 24, 48 and 96 h EC50 were 301.3 mg/L, 208.6 mg/L and 170.61 mg/L, respectively. Although it was performed on the non-standard species Tubifex tubifex, the given data indicate that the study was well-performed and therefore, the results can be considered reliable.

The data on manganese allows estimating a corresponding 96h EC50 for manganese glucoheptonate. The 96h EC50 for manganese glucoheptonate is 1327.1 mg/L for Tubifex tubifex. The 24h and 48h EC50 are 2343.6 and 1618.4 mg/L, respectively.

 

Rathore (2002) tested the 24, 48 and 96h acute toxicity of MnSO4*H2O to Tubifex tubifex. The study was conducted under static conditions and performed according APHA (1989). Tubificid worms were exposed to several concentrations of MnSO4*H2O (referring to metal) for up to 96h at temperatures of 15, 20, 25 and 30 °C. Mortality / immobilization were observed regularly. The 24, 48, 72 and 96 h EC50 values at 20 °C were 422.36 mg/L, 350.16 mg/L, 275.7 mg/L and 275.70 mg/L, respectively.

Although the study was performed on the non-standard species Tubifex tubifex, the given data indicate that the study was well-performed and therefore, the results can be considered reliable.

The data on manganese allows estimating a corresponding 96h EC50 for manganese glucoheptonate thereby, the 96h EC50 for manganese glucoheptonate is 2144.5 mg/L for Tubifex tubifex. The 24h, 48h and 72h EC50 are 3285.3, 2723.7 and 2144.5 mg/L, respectively.

Lasier et al (2000) studied the effect of manganese (added to the test system as manganese chloride) on Hyalella azteca and Ceriodaphnia dubia. Thereby, increasing water hardness significantly reduced toxicity. For Hyalella azteca, the 96h LC50 ranged from 3.0 (soft water) to 13.7 mg/l (hard water). Ceriodaphnia dubia showed higher sensitivity to Mn in soft hard water (mean: 6.2 mg/L) than in moderately hard and hard waters (MH4: 14.5 mg/L; H4: mean: 15.2 mg/L). In general, Ceriodaphnia dubia demonstrated less sensitivity to Mn in soft and moderately hard waters than Hyalella azteca but roughly the same tolerance in hard water. Meyer et al (1994) stated, that the hardness cations, Ca and Mg, can have a competitive effect with respect to the toxicity of divalent metals, including Mn.

For Ceriodaphnia dubia, two ages were tested (<24 h or 24 to 48 h) but the sensitivity of Ceriodaphnia dubia was not significantly affect by Mn within the 48h acute toxicity and the 7d toxicity test. Both ages of Ceriodaphnia dubia reared in MH4 produced significantly (alpha = 0.05) greater numbers of neonates per female than those reared in SW. The mean obtained 7d IC50s for both age groups are 3.9 mg/L (soft water), 8.55 mg/L (moderately hard water) and 11.5 mg/L (hard water).

The reported values for manganese chloride (expressed as mg Mn/L) toxicity to Hyalella azteca correspond to 96h LC50 values that range from 23.3 (soft water) to 106.6 mg/L (hard water) for manganese glucoheptonate. The tests in moderately hard water lead to 96h LC50 values of 70, 66.9 and 63 mg/L for manganese glucoheptonate

The toxicity of manganese chloride to Ceriodaphnia dubia was tested in three water with different hardnesses and for two different age groups of Ceriodaphnia dubia. The age of Ceriodaphnia dubia did not effect the toxicity of the test material. Therefore, the reported 96h LC50 values are the mean of both age groups. The 96h LC50 values for manganese glucoheptonate range from 48.2 mg/L (soft water), over 112. mg/L (moderately hard water) to 118.2 mg/L (hard water).

Since the age of Ceriodaphnia dubia did not influence the induced toxicity, the means of the reported 7d IC50 values were calculated and used for the determination of the corresponding values for manganese glucoheptonate. For manganese glucoheptonate, the corresponding 7d IC50 are 30.3 mg/L (soft water), 66.5 mg/L (moderately hard water) and 89.5 mg/L (hard water).

Conclusion

EC50 and LC0, LC50 as well as LC100 and IC50 were determined by quantitative read-across for manganese glucoheptonate. Thereby, a variety of different species, including Daphnia magna as typical invertebrate test species, were used as test organisms by the authors.The water flea Daphnia magna is an important freshwater species and is recognized as a general representative of other freshwater animals. Most of the used publications were similar to OECD 202 or were performed according APHA, AWWA, WPCF.

Among the studies used for read-across, Daphnia magna was the most sensitive species to manganese glucoheptonate with a 48h LC50 of ≤ 108.00 mg/L (Bringmann, 1959).

Khangarot and Ray (1989) and Biesinger and Christensen (1972) also studied the effect of manganese on Daphnia magna. A good correlation can be found between the 48h EC50 (64.6 mg/L) of Khangarot and Ray (1989) and the 48h LC50 (76.23 mg/L) of Biesinger and Christensen for manganese glucoheptonate. Both values are also similar to the reported 48h LC50 of Bringmann (1959).

On the contrary, the 7d LC0 forCarinogammarus roeselii (Schweiger, 1956) was, with value of 116.68 mg/L,only slightly higher than the LC50s for Daphnia magna. The lowest 7d LC100 (544.48 mg/L) was obtained for the reported data of Carinogammarus roeselii (Schweiger, 1956).

The lowest 96h EC50 of 1327.07 mg/L for manganese glucoheptonate was obtained with the data of Khangarot (1991) for Tubifex tubifex.

The influence of the water hardness on the toxicity of manganese to Ceriodaphnia dubia and Hyalella azteca was studied by Lasier et al (2000). The toxicity of manganese and also of manganese glucoheptonate decreased with increasing water hardness. The lowest LC50 was 23.34 mg/L for Hyalella azteca and 48.23 mg/L for Ceriodaphnia dubia in soft water. With Ceriodaphnia dubia, a 7-d test was conducted, too. The 7d IC50 for managese glucoheptonate range from 30.34 mg/L (soft water) to 89.45 mg/L (hard water).

The age of Ceriodaphnia dubia did not influence the toxicity of manganese glucoheptonate within a 48h- and a 7d-test.

All studies species, except one, were freshwater species. The only studied brackish water species was Nitocra spinipes (Bengtsson, 1978). The recalculated 96h LC50 for manganese glucoheptonate for Nitocra spinipesis 544.48 mg/L.

The studies with the standard test organism Daphnia magna conducted by Bringmann (1959) as well as Khangarot and Ray (1989) are similar to OCED Guideline 202. Both results are similar and in agreement with the findings of Biesinger and Christensen (1972) who used Daphnia magna as test organism, too. Consequently, the key value for chemical safety assessment for freshwater invertebrates is set to the lowest reported 48h EC50 value for Daphnia manga: 64.4 mg/L (Khangerot and Ray, 1989).

Table 1: Lethal concentrations (LC) and effect concentrations (EC) derived from studies performed with various manganese compounds and converted to manganese glucoheptonate (MnGHA).

Species	Duration of exposure	Dose descriptor	Mn GHA (70%) mg/L	water media type	Reference
Tubifex tubifex	24h	EC50	2343.62	freshwater	Khangarot (1991)
Tubifex tubifex	48h	EC50	1618.36	freshwater	Khangarot (1991)
Tubifex tubifex	96h	EC50	1327.07	freshwater	Khangarot (1991)
Tubifex tubifex	24h	EC50	3285.27	freshwater	Rathore (2002)
Tubifex tubifex	48h	EC50	2723.67	freshwater	Rathore (2002)
Tubifex tubifex	72h	EC50	2144.49	freshwater	Rathore (2002)
Tubifex tubifex	96h	EC50	2144.49	freshwater	Rathore (2002)
Tubifex tubifex	7d	LC0	1555.67	freshwater	Schweiger (1956)
Tubifex tubifex	7d	LC100	5444.85	freshwater	Schweiger (1956)
Carinogammarus roeselii	7d	LC0	116.68	freshwater	Schweiger (1956)
Carinogammarus roeselii	7d	LC100	544.48	freshwater	Schweiger (1956)
Chironomus thummy	7d	LC0	1944.59	freshwater	Schweiger (1956)
Chironomus thummy	7d	LC100	7778.36	freshwater	Schweiger (1956)
Anabolia nervosa	7d	LC0	7778.36	freshwater	Schweiger (1956)
Anabolia nervosa	7d	LC100	15556.71	freshwater	Schweiger (1956)
Daphia magna	48h	LC50	<108.00	freshwater	Bringmann (1959)
Daphia magna	48h	LC50	76.23	freshwater	Biesinger and Christensen (1972)
Daphia magna	48h	EC50	64.4	freshwater (240 mg CaCO3/mL)	Khangarot and Ray (1989)
Daphia magna	24h	EC50	77.78	freshwater (240 mg CaCO3/mL)	Khangarot and Ray (1989)
Ceriodaphnia dubia	48h	LC50	48.23	freshwater (soft water)	Lasier et al (2000)
Ceriodaphnia dubia	48h	LC50	112.79	freshwater (moderately hard water)	Lasier et al (2000)
Ceriodaphnia dubia	48h	LC50	118.23	freshwater (hard water)	Lasier et al (2000)
Hyalella azteca	96h	LC50	23.34	freshwater (soft water)	Lasier et al (2000)
Hyalella azteca	96h	LC50	70.01	freshwater (moderately hard water)	Lasier et al (2000)
Hyalella azteca	96h	LC50	66.89	freshwater (moderately hard water)	Lasier et al (2000)
Hyalella azteca	96h	LC50	63	freshwater (moderately hard water)	Lasier et al (2000)
Hyalella azteca	96h	LC50	106.56	freshwater (hard water)	Lasier et al (2000)
Ceriodaphnia dubia	7d	IC50	30.34	freshwater (soft water)	Lasier et al (2000)
Ceriodaphnia dubia	7d	IC50	66.5	freshwater (moderately hard water)	Lasier et al (2000)
Ceriodaphnia dubia	7d	IC50	89.45	freshwater (hard water)	Lasier et al (2000)
Nitocra spinipes	96h	LC50	544.48	brackish water	Bengtsson (1978)