Manganese dichloride

Toxicity to terrestrial arthropods

Administrative data

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.

Cross-reference

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

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:

other: Read-across target

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

Analytical monitoring:

yes

Details on preparation and application of test substrate:

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

Test organisms (species):

Folsomia candida

Animal group:

Acari (soil-dwelling predatory mite)

Study type:

laboratory study

Limit test:

no

Total exposure duration:

28 d

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 100 mg/kg bw

Nominal / measured:

meas. (not specified)

Conc. based on:

other: Mn in soil

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

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

Validity criteria fulfilled:

yes

Remarks:

apart from adult mortality greater than 30% at concentrations higher than 1667 mg/kg and higher concentrations and mean number of juveniles was less than 80 at concentrations higher than 1100 mg/kg. Not considered to affect choice of NOEC.

Conclusions:

The No Observable Effect Concentration (NOEC) is 1067 mg Mn/kgdw.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2002

Materials and methods

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

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 100 mg/kg bw

Nominal / measured:

meas. (not specified)

Conc. based on:

other: Mn in soil

Basis for effect:

mortality

Effect concentrations 2

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 067 mg/kg bw

Nominal / measured:

not specified

Conc. based on:

other: Mn

Basis for effect:

reproduction