2-ethylhexanoic acid, manganese salt

Toxicity to terrestrial arthropods

Administrative data

Endpoint:

toxicity to non-target arthropods on natural substrate (NTA other than pollinators)

Type of information:

calculation (if not (Q)SAR)

Remarks:

Estimated by calculation

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed to a guideline with minimal deviation.

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 28 day NOEC based on reproduction of Folsomia candida is 1067 mg Mn/kg soil.