Manganese dinitrate

Toxicity to terrestrial arthropods

Administrative data

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material

Remarks:

Study performed to a guideline with minimal deviation.The read-across from MnSO4 to Mn(NO3)2 is justified on the following basis: both substances are very soluble in water hence bioavailable and both will release Mn2+ ions. Therefore, from an ecotoxicity standpoint, the nitrate or sulphate anions are not considered to have any influence on the effective toxicity of Mn2+ or any toxicity in their own right, so the anions can be disregarded. Therefore any effect will be related to the Mn2+ cation, and the data from MnSO4 ecotoxicity tests is regarded as a suitable surrogate for read-across

Justification for type of information:

See the read-across report attached in Section 13.

Cross-reference

Reason / purpose for cross-reference:

other: Read-across target

Reference

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

read-across based on grouping of substances (category approach)

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

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

2 444 mg/kg bw

Conc. based on:

other: Mn

Basis for effect:

mortality

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 067 mg/kg bw

Conc. based on:

other: Mn

Basis for effect:

reproduction

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)

Deviations:

yes

Remarks:

The method was adapted for use with natural soils

GLP compliance:

not specified

Application method:

soil

Test material

Test material information

Constituent 1

Reference substance name:

Manganese sulphate monohydrate

IUPAC Name:

Manganese sulphate monohydrate

Details on test material:

- Name of test material (as cited in study report): MnSO4·H2O
- Lot/batch No.: Stock #33341 Lot#H09J07

Sampling and analysis

Analytical monitoring:

yes

Test substrate

Details on preparation and application of test substrate:

The soil was a natural soil containing 1.2% organic matter.

Test organisms

Test organisms (species):

Folsomia candida

Animal group:

Acari (soil-dwelling predatory mite)

Study design

Study type:

laboratory study

Limit test:

no

Total exposure duration:

28 d

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

2 444 mg/kg bw

Conc. based on:

other: Mn

Basis for effect:

mortality

Effect concentrations 2

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 067 mg/kg bw

Conc. based on:

other: Mn

Basis for effect:

reproduction

Any other information on results incl. tables

The natural background Mn concentration determined in the negative control treatment was 94 mg kg-I. Total extractable Mn concentrations (in excess of background) in the experimental treatments ranged from 99 to 140% and averaged 111% of nominal. Exchangeable Mn fraction expressed as percent of total concentration increased with increasing soil Mn loads.

Range finding test:

Manganese sulphate monohydrate (MnSO4·H2O) was used to conduct a range finding test. Adult survival and juvenile production decreased significantly at 5,000 mg/kg. There were no juveniles above the 5,000 mg/kg treatment concentration.

Definitive test:

Manganese did not affect (P = 0.168) adult springtail survival at the 1667 mg/kg concentration. Adult survival was significantly reduced (P = 0.0001) at 2444 mg/kg. The bounded NOEC for juvenile production was 1067 mg/kg (P=0.070). The bounded LOEC for juvenile production was 1100 mg/kg (P=0.025). No juveniles were produced in 2444 mg/kg treatment. The

EC20 and EC50 values for Mn for juvenile production were 1209 and 1663 mg/kg, respectively.

Table 1: Nominal and measured concentrations of manganese

Nominal (mg/kg)	Measured (mg/kg)	Corrected recovery (%)
0	94	0
287	386	102
500	633	108
695	1067	140
966	1100	104
1343	1667	117
1867	2444	126
2594	2836	106
3606	3667	99
5056	5056	99

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The lowest NOEC was 1067 mg/kg for reproductive effects. The read-across from MnSO4 to Mn(NO3)2 is justified on the following basis: both substances are very soluble in water hence bioavailable and both will release Mn2+ ions. Therefore, from an ecotoxicity standpoint, the nitrate or sulphate anions are not considered to have any influence on the effective toxicity of Mn2+ or any toxicity in their own right, so the anions can be disregarded. Therefore any effect will be related to the Mn2+ cation, and the data from MnSO4 ecotoxicity tests is regarded as a suitable surrogate for read-across