Dialuminium zinc tetraoxide

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 Jun 2016 - 13 Jul 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Ministry of environmental protection of the people´s Republic of China, The Guidelines for the Testing of Chemicals - Effects on Biotic Systems, 207 Earthworm, Acute Toxicity Test

Version / remarks:

2013

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil: An amount of the test substance was separately added to a certain amount of silica sand and then incorporated into formulated artificial soil with deionized reverse osmosis water. The test matrix components (2520.2 mg test substance, 41.7 g silica sand, 600 mL water and 2478 g dry artificial soil) were mixed by a mixer with a nominal moisture of 40-60%. The test matrix components were mixed evenly and distributed into 4 containers. Each container was loaded with approx. 750 g wet weight of the substrate. The same procedure was followed for the blank control without adding the test substance.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: earthworm
- Source: Jiang Su province Jurong Stock Farm. All acquired earthworms were observed for 14 d prior to use.
- Age at test initiation (mean and range, SD): adult earthworms (with clitellum)
- Weight at test initiation (mean and range, SD): 300 - 600 mg

ACCLIMATION
- Acclimation period and conditions: Earthworms were bred on a substrate consisting of 50% peat and 50% cow manure and kept under 20±2°C for 7 d prior testing. Test organisms were then transferred into artificial soil (without test substance) approx. 24 h prior to start of the test.

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

20.3 - 20.5 °C

pH:

6.22 - 6.33

Moisture:

Day 0: 28.57% in the blank control and 29.91% in the treatment group
Day 14: 27.95% in the control and 28.73% in the treatment group

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1 L closed glass vessel.
- Amount of soil or substrate: 750 g wet weight substrate.
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- % sphagnum peat: 10% w/w
- % sand: 70% w/w
- % kaolinite clay: 20% w/w
- Maximum water holding capacity (in % dry weight): 52% (determined according to OECD 222).

OTHER TEST CONDITIONS
- Photoperiod: continuous illumination
- Light intensity: 603 - 625 lux

EFFECT PARAMETERS MEASURED:
- Mortalities were recorded after 7 and 14 d. Total gross weight of the earthworms was recorded on Day 0. Surviving earthworms were weighed on Day 14.

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 0 (control), 10, 100, 1000 mg/kg (no replicates)
- Results used to determine the conditions for the definitive study: Based on the results of the range finding study (no mortalities within 14 d), one treatment group and one blank control group which had four replicates of 10 worms per replicate were included in the limit test (1000 mg/kg).

Nominal and measured concentrations:

Nominal concentration: 1000 mg/kg soil dw

Reference substance (positive control):

yes

Remarks:

chloroacetamide, determined once a year (most recent test 19 Jan - 2 Feb 2016, 14 d test with concentrations of 3.75, 7.5, 15, 30 and 60 mg/kg)

Duration:

7 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality at end of exposure period: 0% on Day 7 and 2.5% on Day 14.
- Mortality in control group at the end of exposure: 0%
- Total mass of adults at beginning of test: 447 - 459 mg in blank control and 467 - 493 mg in treatment group.
- Changes in body weight of live adults (% of initial weight) at end of exposure period: 8 ± 5.34% in control and 10.39 ± 4.34 % in treatments.
- Morphological abnormalities: no
- Behavioural abnormalities: no
- Other biological observations: no

Results with reference substance (positive control):

- Results with reference substance valid: yes
- Relevant effect levels: LC50 (14 d) = 25.7 mg/kg soil dw

Table 1: Mortality of E. fetida exposed to the test substance and controls after 7 and 14 days.

Parameter	Blank control		Treatments
Duration [d]	7	14	7	14
Number of earthworms	40	40	40	40
Number of mortality total	0	0	0	1
Mortality %	0	0	0	2.50%

No pathological or behavioural symptoms were observed.

Table 2: Average body weight of the surviving earthworms on Day 0 and 14.

Groups	Day 0		Day 14		Weight reduction 14 d (%)± standard deviation
	No of worms	Mean weight [mg]	No of worms	Mean weight [mg]
Blank control	10	452	10	439	8± 5.34%
	10	459	10	404
	10	484	10	465
	10	447	10	388
Treatment	10	489	10	407	10.39± 4.34 %
	10	467	10	434
	10	493	9	450
	10	490	10	446

Validity criteria fulfilled:

yes

Description of key information

LC50 (14 d) > 1000 mg/kg soil dw (nominal, Eisenia fetida, OECD 207)

Additional information

One study is available testing the toxicity of the substance towards earthworms (2016). The study was conducted according to OECD guideline 207 and GLP standards. The earthworm species Eisenia fetida was exposed to a single nominal test substance concentration of 1000 mg/kg soil dw and a control for 14 d. No mortalities were observed in the control. The study resulted in an LC50 (14 d) of > 1000 mg/kg soil dw (nominal).