OligoActiv EDDHA-Mn

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:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Since the analytically determined concentrations of the test substance in the test solutions were within +/- 20 % of the nominal concentrations, the effect concentration can be expressed relative to the nominal concentration.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50/LC50: The EC50(24h) of the reference substance potassium dichromate was 1.19 mg/L.
- Other: This result is within the range of 0.6 – 2.1 mg/L (ISO 6341) and indicates that the culture of Daphnia magna used in this study is responding normally to toxic stress.

Reported statistics and error estimates:

Since the study is designed as a limit test, no statistical analysis was performed.

Number of mobile daphnids

Nominal concentration [mg/L]	Replicate 1 [h]			Replicate 2 [h]			Replicate 3 [h]			Replicate 4 [h]			∑	∑
	0	24	48	0	24	48	0	24	48	0	24	48	24	48
0 (control)	5	5	5	5	5	5	5	5	5	5	5	5	20	20
120	5	5	5	5	5	5	5	5	5	5	5	5	20	20

Effect concentrations after 24 hours and 48 hours of exposure. The EC values based on nominal concentrations were:

Time [h]	EC0 [mg/L]	EC50 [mg/L]	Confidence limits 95% [mg/L]	EC100 [mg/L]
24	>120	> 120	* – *	> 120
48	>120	> 120	* – *	> 120

*The data were insufficient to determine confidence limits.

Validity criteria fulfilled:

yes

Remarks:

Validity criteria of the test guideline were fulfilled.

Conclusions:

In conclusion the 48 hour EC50 values for FeNaEDDHA in this acute toxicity study with Daphnia magna were > 120 mg/L based on the nominal concentration of the test substance and > 122 mg/L based on the mean measured concentrations. The same result is expected for the organic constituents of target substance since it has the same composition as the source substance.

Executive summary:

This acute toxicity study investigated the effect of Fe(Na)EDDHA on the immobilisation of Daphnia magna according to the principles of OECD Guideline 202 and EU Method C.2. Juvenile daphnids (younger than 24 hour old) were exposed to one concentration of the test substance and compared to a control. Immobilisation of daphnia is determined after 24 and 48 hours of exposure. The test substance was was tested at 120 mg/L. The 48 hour EC50 value for the test substance was greater than 120 mg/L based on the nominal concentration of the test substance and greater than 122 mg/L based on the mean measured concentrations. Since the analytically determined concentrations of the test substance in the test solutions were within +/- 20% of the nominal concentrations, the effect concentration is expressed relative to the nominal concentration for the evaluation of the test substance.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

130.67 mg/L

Conc. based on:

element

Remarks:

converted to target substance

Calculation of the LC50 value for target substance:

concentration of Mn in target substance: 7.5 %

 

LC50 for manganese = 9.8 mg/L

LC50 of target substance = 9.8 mg/L/0.075 = 130.67 mg/L

Conclusions:

Converted to the manganese moiety in the target substance the LC50 (48h) corresponds to 131 mg/L.

Executive summary:

The LC50 for the toxicity of MnCl2 to Daphnia magna, expressed as mg manganese per liter, allows estimating a corresponding 48h LC50 for the manganese moiety in the target substance. Converted to the manganese moiety in the target substance the LC50 (48h) corresponds to 131 mg/L.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

933.33 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

converted to target substance

Basis for effect:

mortality

Calculation of the LC50 value for target substance:

concentration of Mn in target substance: 7.5 %

 

LC50 for manganese = 70 mg/L

LC50 of target substance = 70 mg/L/0.075 = 933.33 mg/L

Conclusions:

The LC50 (96 h) in Nitocra spinipes converted to the target substance corresponds to 933 mg/L.

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.

The LC50 (96 h) in Nitocra spinipes converted to the target substance corresponds to 933 mg/L.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

110.4 mg/L

Conc. based on:

element

Remarks:

converted to target substance

Basis for effect:

mortality

Calculation of the LC50 value for target substance:

concentration of Mn in target substance: 7.5 %

 

LC50 for manganese = 8.28 mg/L

LC50 of target substance = 8.28 mg/L/0.075 = 110.4 mg/L

Conclusions:

Converted to the target substance the EC50 (48 h) value for the manganese moiety in the target substance in Daphnia magna is 110 mg/L.

Executive summary:

The EC50 for the toxicity of MnSO₄ to Daphnia magna, expressed as mg manganese per liter, allows estimating a corresponding 48h EC50 for the manganese moiety in the target substance. The resulting EC50 (48 h) value is 110 mg/L.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Remarks:

Hyalella azteca

Effect conc.:

> 40 - < 182.67 mg/L

Conc. based on:

element

Remarks:

converted to target substance

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.:

> 76 - < 89.33 mg/L

Conc. based on:

element

Remarks:

converted to target substance

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.:

193.33 mg/L

Conc. based on:

element

Remarks:

converted to target substance

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.:

> 193.33 - < 212 mg/L

Conc. based on:

element

Remarks:

converted to target substance

Basis for effect:

mortality

Remarks on result:

other: hard water (H4)

Calculation of the LC50 value for target substance:

concentration of Mn in target substance: 7.5 %

 

LC50 for manganese = 3 mg/L

LC50 of target substance = 3 mg/L/0.075 = 40 mg/L

LC50 for manganese = 13.7 mg/L

LC50 of target substance = 13.7 mg/L/0.075 = 182.67 mg/L

LC50 for manganese = 5.7 mg/L

LC50 of target substance = 5.7 mg/L/0.075 = 76 mg/L

LC50 for manganese = 6.7 mg/L

LC50 of target substance = 6.7 mg/L/0.075 = 89.33 mg/L

LC50 for manganese = 14.5 mg/L

LC50 of target substance = 14.5 mg/L/0.075 = 193.33 mg/L

LC50 for manganese = 15.9 mg/L

LC50 of target substance = 15.9 mg/L/0.075 = 212 mg/L

Conclusions:

The reported values for manganese chloride (expressed as mg Mn/L) in Ceriodaphnia dubia correspond to LC50 values that range from 76 (soft water) to 212 mg/L (hard water) for the manganese moiety of the target substance.

Executive summary:

The LC50 for manganese chloride’s toxicity to Hyalella azteca and Ceriodaphnia dubia, expressed as mg manganese per liter, allows estimating a corresponding 48h LC50 for the manganese moiety in the target substance.  

 

For Hyalella azteca, 96h LC50 values were determined in five water with different hardnesses: one soft water, three moderately hard water and one hard water were tested. The reported values for manganese chloride (expressed as mg Mn/L) correspond to 96h LC50 values that range from 40 (soft water) to 183 mg/L (hard water) for the manganese moiety of in the target substance. 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. The respective 48h LC50 values for the manganese moiety of the target substance range from 76 - 89 mg/L (soft water), over 193 mg/L (moderately hard water) to 193 - 212 mg/L (hard water).

Reference 6

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4 668.8 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

converted to target substance

Basis for effect:

mortality

Calculation of the LC50 value for target substance:

concentration of Mn in target substance: 7.5 %

 

LC50 for manganese = 350 mg/L

LC50 of target substance = 350 mg/L/0.075 = 4668.8 mg/L

Conclusions:

The EC50 (48 h) for the manganese moiety in the target substance is 4669 mg/L for Tubifex tubifex.

Executive summary:

The data on manganese allows estimating a corresponding 48h EC50 for the manganese moiety in the target substance. The EC50 (48 h) for the manganese moiety in the target substance is 4669 mg/L for Tubifex tubifex.

Description of key information

An EC50 (48h) value of > 120 mg/L is reported for Fe(Na)EDDHA in a study conducted with D. magna (OECD TG 202, GLP; Salinas (2010)). Thus, the EDDHA chelate is clearly not acutely toxic to aquatic invertebrates.

To address the toxicity of the manganese ion in the target substance the key value for chemical safety assessment for toxicity to invertebrates was set to the lowest EC50 obtained in a test similar to a recommended test method (OECD TG 202). The selected EC50 (48 h) value is 8.28 mg Mn/L. It was determined in a study with D. magna (Khangarot 1989). Converted to the manganese moiety in the target substance taking into account the maximum amount of manganese in the target substance, this corresponds to an EC50 (48 h) of 110 mg/L for the target substance. For the whole evaluation of the available data on manganese compounds please refer to 'Additional information'.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

110 mg/L

Additional information

Manganese compounds

The effect concentrations and lethal concentrations of manganese were 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, Ceriodaphnia dubia, Hyalella azteca, and Nitocra spinipes. The EC50 values found in literature were converted to corresponding values of the target substance (please see Table 1 for a summary of calculated EC-values for the target substance). Thereby, it is assumed that no toxicity is attributed to the possibly present anion (Cl2(2 -)or SO4(2 -)).

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 study was performed similar to OECD Guideline 202 with minor deviations. The lethal concentrations (EC50) were determined by the immobilisation test. Test daphnid were presumed dead when there was complete immobilisation (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 calculated 48h EC50 describing the toxicity of manganese moiety in the target substance to Daphnia magna is 110 mg/L.

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 corresponding calculated 48h EC50 describing the toxicity of manganese moiety in the target substance to Daphnia magna is 131 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 immobilisation) 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 the target substance. The corresponding calculated 96 h LC50 describing the toxicity of manganese moiety in the target substance to Nitocra spinipes is 933 mg/L.

 

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 / immobilisation 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 corresponding calculated EC50 (48 h) describing the toxicity of manganese moiety in the target substance to Tubifex tubifex is 4669 mg/L.

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 water (mean: 6.2 mg/L) than in moderately hard (14.5 mg/L) and hard waters (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.

The reported values for manganese chloride (expressed as mg Mn/L) toxicity to Hyalella azteca correspond to 96h LC50 values ranging from 40 mg/L (soft water) to 183 mg/L (hard water) when calculated for the toxicity of manganese moiety in the target substance.

The toxicity of manganese chloride to Ceriodaphnia dubia was tested in three waters 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 reported values for manganese chloride (expressed as mg Mn/L) toxicity to C. dubia correspond to 96h LC50 values ranging from 76 mg/L (soft water) to 212 mg/L (hard water) when calculated for the toxicity of manganese moiety in the target substance.

Conclusion

EC50 values were determined by quantitative read-across for the manganese moiety in the target substance. In the studies a variety of different species, including Daphnia magna as typical invertebrate test species, were used as test organisms.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.

The studies with the standard test organism Daphnia magna conducted by Biesinger and Christensen (1972) as well as Khangarot and Ray (1989) are similar to OECD Guideline 202. Both results are similar and in agreement with the findings of Lasier (2000) who used Ceriodaphnia dubia as test organism. Consequently, the key value for chemical safety assessment for freshwater invertebrates is set to the lowest reported 48h EC50 value for Daphnia manga: 110 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 the target substance.

Species	Duration of exposure	Dose descriptor	target substance (mg/L)	water media type	Reference
Tubifex tubifex	24h	EC50	5631	freshwater	Rathore (2002)
Tubifex tubifex	48h	EC50	4669	freshwater	Rathore (2002)
Tubifex tubifex	72h	EC50	3676	freshwater	Rathore (2002)
Tubifex tubifex	96h	EC50	3676	freshwater	Rathore (2002)
Daphia magna	48h	LC50	131	freshwater	Biesinger and Christensen (1972)
Daphia magna	48h	EC50	110	freshwater (240 mg CaCO3/mL)	Khangarot and Ray (1989)
Ceriodaphnia dubia	48h	LC50	76 - 89	freshwater (soft water)	Lasier et al (2000)
Ceriodaphnia dubia	48h	LC50	193	freshwater (moderately hard water)	Lasier et al (2000)
Ceriodaphnia dubia	48h	LC50	193 - 212	freshwater (hard water)	Lasier et al (2000)
Hyalella azteca	96h	LC50	40	freshwater (soft water)	Lasier et al (2000)
Hyalella azteca	96h	LC50	183	freshwater (hard water)	Lasier et al (2000)
Nitocra spinipes	96h	LC50	933	brackish water	Bengtsson (1978)