Manganese carbonate

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted was equivalent to a current guideline method; results were reported to a sufficient level of detail to assess the quality of the relevant results.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

GLP compliance:

not specified

Analytical monitoring:

yes

Test organisms (species):

Salvelinus fontinalis

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

65 d

Duration:

65 d

Dose descriptor:

NOEC

Effect conc.:

0.55 mg/L

Conc. based on:

other: Mn

Basis for effect:

length

Weight:

Growth, as measured by terminal body weight, was significantly reduced by exposure to Mn . The NOECs based on growth for the ELS brook trout tests in 30 and 150 hardness were 0.85 and 3.53 mg Mn/litre, respectively while the LOECs were 2.18 and 7.53 mg Mn/litre, respectively. For brook trout fry, the NOEC and LOEC in the 30 hardness experiment was 2.53 and 5.35 respectively. In the 150 hardness, the NOEC and LOEC was 1.71 and 3.59 respectively.

Length:

Lengths were collected at termination of tests. In the test conducted at 30 hardness, the NOEC and LOEC based on length (0.55 and 0.85 mg/L, respectively) were more sensitive than either weight or mortality. For the test conducted in 150 hardness water, the NOEC and LOEC based on length was 3.53 and 7.53.

Hatching:

Hatching success exceeded 90 percent in all treatments and was unaffected by manganese exposure over the range of concentrations tested.

Table 1: Hatching success

Total Mn (mg/L)	Hatching success (%)	Mean time to hatch (days)	Total Mn (mg/L)	Hatching success (%)	Mean time to hatch (days)
30 Hardness			150 Hardness
0.03	100	9.1	<0.02	97.5	10.4
0.36	97.5	9.1	0.78	100	10.4
0.55	100	9.4	1.68	97.5	10.5
0.85	100	9.0	3.53	97.5	10.6
2.18	97.5	9.2	7.53	100	10.0
4.48	97.5	9.0	15.65	95	9.2
8.94	97.5	8.2	34.34	97.5	7.3
19.90	95	7.1	73.72	95	4.8

Table 2: Effect data

Mortality		Length		Weight
NOEC mg/L	LOEC mg/L	NOEC mg/L	LOEC mg/L	NOEC mg/L	LOEC mg/L
30 Hardness
2.18	4.48	0.55	0.85	0.85	2.18
150 Hardness
7.53	15.65	3.53	7.53	3.53	7.53

Table 3: water quality characteristics 

Statistics	Hardness (as CaCO3) mg/L	Alkalinity (as CaCO3) mg/L	pH	Dissolved oxygen mg/L	Temperature °C	Conductivity µS/c,
	30 Hardness
Mean	31.2	24.6	7.19	8.95	12.2	62.3
Range	24.4 - 35.2	15.8 - 32.6	6.26-7.96	7.1 - 9.8	11.0 - 13.2	52.7 - 70.5
	150 Hardness
Mean	155.5	111.0	7.43	8.80	12.1	274
Range	148.4 -164.2	101.4 -125.2	6.97 -7.96	7.4 -9.9	11.1 -12.8	255 -297

Table 4: Summary of anions for laboratory dilution waters

Parameter mg/L	30 Hardness		150 Hardness
	Mean	Range	Mean	Range
Fluoride	0.65	0.20 – 0.80	0.60	0.50 – 0.90
Chloride	1.42	0.80 – 1.80	6.75	2.00 – 8.20
Nitrate	0.94	0.50 – 5.40	6.16	0.70 – 7.20
Phosphate	<0.5	- -	<0.5	- -
Sulphate*	7.0	7.0 – 7.1	55.0	52.0 – 59.6

* Data represents measurements from control tank only

Validity criteria fulfilled:

yes

Remarks:

with the exception that the daily temperatures are not reported

Conclusions:

Under the conditions of the study the 65 day NOEC, in terms of length, was 0.55 mg Mn/L in 30 hardness water.

Executive summary:

Under the conditions of the study the 65 day NOEC, in terms of length, was 0.55 mg Mn/L in 30 hardness water.

This study was conducted on the soluble manganese substance MnSO4 and the results are used for classification and labelling purposes, as discussed in section 6.

Reference 2

Endpoint:

fish early-life stage toxicity

Type of information:

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

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material

Justification for type of information:

See the read-across report attached in Section 13.

Reason / purpose for cross-reference:

read-across source

Description of key information

Under the conditions of the study the 65 day NOEC, in terms of length, was 0.55 mg Mn/L. Result read-across from manganese sulphate.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Remarks:

Result quoted in mg Mn/L

Effect concentration:

0.55 mg/L