Rhodium acetate

Toxicity to terrestrial arthropods

Administrative data

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Not GLP compliant. Minimum number of test concentrations. No details of analytical verification of the test material concentrations.

Data source

Reference

Reference Type:

publication

Title:

Impact of platinum group elements on the soil invertebrate Enchytraeus crypticus

Author:

Havelkova. B et al.

Year:

2014

Bibliographic source:

Neuroendocrinology Letters 35 (2) 101–108

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: ISO 16387 OECD 220

GLP compliance:

no

Application method:

soil

Test material

Test material information

Constituent 1

Reference substance name:

Rhodium trichloride

EC Number:

233-165-4

EC Name:

Rhodium trichloride

Cas Number:

10049-07-7

Molecular formula:

Cl3Rh

Test material form:

other: solution

Sampling and analysis

Analytical monitoring:

no

Test substrate

Details on preparation and application of test substrate:

nominal concentrations 50, 100, 150, 200 and 250 μmol/L RhCl3

Test organisms

Test organisms (species):

other: Enchytraeus crypticus

Animal group:

other: Soil dewelling worm

Details on test organisms:

Originated in cultures from the Ecotoxicological laboratory of the University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic.

Study design

Study type:

laboratory study

Limit test:

yes

Total exposure duration:

28 d

Test conditions

Test temperature:

20±2 °C

pH (if soil or dung study):

6.0±0.5

Humidity:

50% soil moisture

Photoperiod and lighting:

16:8 (light/dark) photoperiod

Details on test conditions:

Within each vessel, ten adult enchytraeids of approximately the same size, with eggs in the clitellum region were placed in 20g soil. As food supply, finely ground rolled oats were added. Additional food and water were added when required.

Nominal and measured concentrations:

nominal concentrations 50, 100, 150, 200 and 250 μmol/L RhCl3

Reference substance (positive control):

yes

Remarks:

Boric acid

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

246.2 other: μmol/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Effect concentrations 2

Duration:

28 d

Dose descriptor:

LC50

Effect conc.:

247.2 other: μmol/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Effect concentrations 3

Key result

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

48.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

reproduction

Remarks on result:

other: self calculated using Trap v1.30a

Effect concentrations 4

Key result

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

32.7 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

reproduction

Remarks on result:

other: self estimated using Trap v1.30a

Details on results:

A significant effect on mortality and reproduction was observed.

Results with reference substance (positive control):

boric acid EC50 150– 170 mg/kg dry weight soil

Reported statistics and error estimates:

One-way analysis of variance (ANOVA) and post-hoc analysis of means by the LSD test.
Levene’s method was used to test for the homogeneity of variances.
Non-homogenous parameters were log-transformed prior to analysis and compared with the non-parametric Kruskal-Wallis test.

Any other information on results incl. tables

Concentrations RhCl3(μmol/L)	No. adult		Mortality (%)	No. juveniles produced (mean ± SD)	CV (%)	Inhibition of reproduction (%)
	at the beginning of the test	at the end of the test
50	10	10	0	128.8±16.5	13	1
100	10	9.2	8	126.0±21.8	17	3
150	10	9	10	124.4±17.7	14	4
200	10	6.2	38	95.2±15.7	16	27
250	10	4.4	56	60.6±26.7	44	53

reported	28d EC50	247.2
recalculated	EC10	164.7
	EC50	243.5

		RhCl3 (micromol/L)	Rh (micromol/L)	Rh (microg/L)	Rh (mg/L)	Rh (mg/kg ww)	Rh (mg/kg dw)
EC10		164.7	81.0	8335.3	8.3	28.9	32.7
EC50		243.5	119.7	12323.3	12.3	42.8	48.3
		MW RhCl3	209.26	2.033427
		MW Rh	103
		Kd soil	3.8	L/kg
		Ksoil-water	5.9	m3/m3
		RHOsolid	1700	kg/m3
		Dry weight conversion	1.13

Applicant's summary and conclusion

Conclusions:

Rhodium trichloride was shown to have a significant effect on the reproduction and mortality of Enchytraeus crypticus under the chosen test conditions. The 28 day EC50 was reported to be 246.2 μmol/L with the inhibition of reproduction at 53% when the organisms were exposed to 250 μmol/L . The study was not conducted according to GLP and has a reliability rating of 2 (reliable with restrictions). The EC10 and EC50 values were recalculated to be 32.7 and 48.3 mg Rh/kg dw, respectively.

Executive summary:

The influence of rhodium trichloride on the reproduction and mortality of the species Enchytraeus crypticus was investigated according to OECD Test Guideline 220, "CSN EN ISO 16387 – Soil quality – Effects of pollutants on Enchytraeidae (Enchytraeus sp.) – Determination of effects on reproduction". Test specimens were placed in synthetic soil treated with nominal rhodium trichloride concentrations of 50, 100, 150, 200, 250 umol/L. The experiments were carried out with five replicates. The 28 day EC50 for rhodium trichloride was found to be 246.2 umol/L. When the Enchytraeus crypticus were exposed to 250 umol/L rhodium trichloride, the inhibition of reproduction was 53%. A significant effect of mortality was also observed. The EC10 and EC50 values were recalculated to be 32.7 and 48.3 mg Rh/kg dw, respectively.

This study has a reliability rating of 2 (reliable with restrictions) as there is no evidence of analytical verification of test material concentrations. The study was not conducted according to GLP with only the minimum number of test concentrations.