Activated Carbon - Low Density Skeleton

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

5/2/2013 - 29/4/2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study according to international guideline (OECD guideline 222) under GLP. No deviations from guideline reported. The study was assigned a Klimisch 2 rating due to the read-across purpose, in accordance with the ECHA Practical guide #6 on the reporting of read-across in IUCLID.

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Reference

As the test substance does not solve in water, the mechanism of partitioning from the water phase and thus uptake by diffusion from the water phase does not take place. Thus exposure of terrestrial organisms to the test substance may occur only by oral intake of solid particles of the test substance. An effect in the organism would then be caused by internal partitioning of test substance (as modelled by equilibrium partitioning and for highly lipophilic substance with an additional factor of 10, see Guidance Document on Information Requirements and Chemical Safety Assessment R.10 and R.16). However, for activated carbon no absorption is expected (see toxicokinetic assessment). The absence of effects from oral intake of activated carbon is supported by the results of an acute toxicity study with rats where no adverse effects were observed after oral exposure to 2000 mg/kg (C80453). To demonstrate the absence of effects in terrestrial organisms, a reproduction toxicity test with earthworms (OECD 222) was performed with Activated Carbon - High Density Skeleton. This study was read across to Activated Caron- Low Density Skeleton in this dossier. The NOEC in this study was observed to be 1000 mg/kg soil. Therefore further testing with terrestrial organisms is waived.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)

Deviations:

no

Principles of method if other than guideline:

not relevant

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Activated carbon powder (coconut based)

IUPAC Name:

Activated carbon powder (coconut based)

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Activated carbon powder (coconut based)
- Substance type: Black powder
- Physical state: solid
- Storage condition of test material: At room temperature (20 ± 5 °C), under dark and dry conditions

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not relevant

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

not relevant

Test substrate

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil:Activated carbon powder (coconut based) was weighed separately for each concentration using an analytical balance and fine quartz sand was added until a final net weight of 20 g was reached. After mixing with a spoon to reach a homogeneous distribution of the test item within the sand the mixture was added to artificial soil equivalent to 2030 g dry weight. While mixing the artificial soil in a laboratory mixer for approximately 5 min the soil of each treatment group was moistened with deionised water. Each group was treated in one batch (two in the control) which was then split into the replicates.
- Controls: Untreated soil (same amount of untreated quartz sand as in the test item groups and moistened with deionised water)

Test organisms

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Eisenia fetida (Savigny 1826)
- Source: Bred under standardised conditions in IBACON laboratories
- Age at test initiation: Adults, Approximately 12 months, with well-developed clitellum, age range between test individuals not differing by more than 4 weeks
- Weight at test initiation: 300 mg to 600 mg

ACCLIMATION
- Acclimation period: 1 day, in artificial soil, under test conditions
- Acclimation conditions: same as test conditions

Study design

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

8 wk

Post exposure observation period:

After 4 weeks, adult worms were counted, removed and weighed per replicate after being washed under tap water and dried on paper towels. Missing earthworms and earthworms that failed to respond to gentle stimulation were considered to be dead. The remaining soil (without the adult worms) was then returned to the respective test containers. Exposure Time of Offspring: Additional 28 days after removal of the adult worms.

Test conditions

Test temperature:

18-22 ºC

pH:

6.0 ± 0.5

Moisture:

At experimental start: 18.9% to 19.2% (52.5% to 53.4% of the maximum water holding capacity)
At experimental end: 19.5% to 22.3% (54.2% to 61.9% of the maximum water holding capacity)

Details on test conditions:

TEST SYSTEM
- Test container: Plastic boxes (18.3 cm x 13.6 cm x 6 cm, tapered towards the bottom, with a soil surface of approximately 16.5 cm x 11.5 cm = 189.75 cm²) with perforated transparent lids to enable exchange of air, to minimise evaporation from the artificial soil, and to prevent the worms from escaping.
- Amount of soil or substrate: Each container was filled with 598.6 g of the prepared soil (500 g dry weight plus deionised water plus 5 g food). The height of the soil layer in the containers was approximately 4 - 5 cm.
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 8

SOURCE AND PROPERTIES OF SUBSTRATE
- Composition (artificial substrate): Based on OECD 222 but with reduced organic matter content:
• 5% Sphagnum-peat, air-dried and finely ground (2 mm); (Floragard, Vertriebs GmbH für Gartenbau, 26138 Oldenburg, Germany)
• 20% Kaolin clay (Erbslöh, 65558 Lohrheim, Germany)
• 74.8% fine quartz-sand (F34) containing more than 50% by mass of particle size 0.05 mm to 0.2 mm; (Quarzwerke Frechen, Postfach 1780, 50207 Frechen, Germany)
Calcium carbonate (CaCO3) was added to adjust pH to 6.0 ± 0.5 (Merck, 64293 Darmstadt, Germany).
The artificial soil was moistened to approximately half of the final water content 1 day before the application. The additional water required to achieve the final water content was added when applying the test item.
- Maximum water holding capacity:36% of the dry weight

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark
- Light intensity: Within the range of 400 lux to 800 lux

EFFECT PARAMETERS MEASURED :
- Number of dead adult earthworms at day 28 after application (including any missing ones)
- Number of affected adult earthworms (e.g. lack of movement, rigidity, etc) at day 28 after application
- Body weights were determined at start (day 0) and 28 days after application
- Number of juveniles 56 days after introduction of the test animals
After 4 weeks, adult worms were counted, removed and weighed per replicate after being washed under tap water and dried on paper towels.
The remaining soil (without the adult worms) was then returned to the respective test containers. Exposure Time of Offspring: Additional 28 days after removal of the adult worms.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Range finding study: no

Nominal and measured concentrations:

nominal: 31.6, 100.0, 316.0, 1000.0, 3200 mg/kg soil

Reference substance (positive control):

yes

Remarks:

Carbendazim

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

4 wk

Dose descriptor:

NOEC

Effect conc.:

3 200 other: mg/kg soil

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Effect concentrations 2

Key result

Duration:

4 wk

Dose descriptor:

NOEC

Effect conc.:

1 000 other: mg/kg soil

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: weight

Effect concentrations 3

Key result

Duration:

8 wk

Dose descriptor:

NOEC

Effect conc.:

3 200 other: mg/kg soil

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

- Mortality at end of exposure period (28 d): 0%

Results with reference substance (positive control):

- Results with reference substance valid
- Relevant effect levels: EC50 1.7 mg/kg soil

Reported statistics and error estimates:

Standard procedures, Williams t-test (weight changes) and Bonferroni-Welch t-test (reproduction).

Any other information on results incl. tables

Validation criteria were met: Control mortality was 0%. The number of juvenile worms per replicate was 185 to 312. The coefficient of Variance of Reproduction in Control was 21.5%.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

All study validity criteria were met

Conclusions:

In an earthworm reproduction and growth study with Activated carbon powder (coconut based) the No Observed Effect Concentration (NOEC) for growth, reproduction and feeding activity of the earthworm Eisenia fetida was determined to be 1000 mg test item/kg soil.

Executive summary:

In an earthworm reproduction and growth study according to OECD guideline 222 with Activated carbon powder (coconut based) the No Observed Effect Concentration (NOEC) for growth, reproduction and feeding activity of the earthworm Eisenia fetida was determined to be 1000 mg test item/kg soil.