Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:
toxicity to soil macroorganisms except arthropods: long-term
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP Guideline Study
Justification for type of information:
Please refer to the Category document for further details.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))
Deviations:
no
Qualifier:
according to guideline
Guideline:
ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Benzene, 1,1'-oxybis-, tetrapropylene derivs., sulfonated, sodium salts
EC Number:
601-601-6
Cas Number:
119345-04-9
Molecular formula:
C24H32O7S2Na2
IUPAC Name:
Benzene, 1,1'-oxybis-, tetrapropylene derivs., sulfonated, sodium salts
Test material form:
other: liquid at ambient temperatures
Details on test material:
- Name of test material (as cited in study report): Dowfax 2A1 Solution Surfactant
- Physical state: liquid
- Purity test date: May 29, 2012
- Lot/batch No.: Mii081863
- Expiration date of the lot/batch: May 29, 2014
- Storage condition of test material: ambient

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Triplicate samples were collected from the stock solutions used to prepare the highest and lowest concentrations of the test soils. Water purified by reverse osmosis was collected for a control sample. Following collection, samples were transferred to the analytical chemistry laboratory for analysis.

Test substrate

Details on preparation and application of test substrate:
The artificial soil was prepared in bulk by blending approximately 70% sand, 20% kaolin clay and 10% sphagnum peat. The pH of the bulk soil prior to hydration was adjusted to 5.9 using calcium carbonate. The bulk artificial soil was stored in a sealed container under ambient conditions until used to prepare the test soils.
Test soil was prepared by premixing the appropriate amount of the test substance water purified by reverse osmosis and mixing it with dry artificial soil. Sufficient reverse osmosis water was added to the dry artificial soil to achieve a moisture content of approximately 34% by weight. Test soil
components were mixed for a total of 20 minutes in order to achieve a homogeneous mixture. Negative control soil was prepared in the same
manner as the treated soil but with only the addition of water. Seven hundred fifty grams of prepared soil were added to each test chamber.
Test concentrations are reported as milligrams per kilogram of soil on a dry weight basis (mg/kg).
The water and soil used in earthworm studies are periodically screened for pesticides and metals. Results of the most recent analyses indicated that no analytes were measured at levels that were expected to have an impact on the study.

Test organisms

Test organisms (species):
Eisenia fetida
Animal group:
annelids
Details on test organisms:
Adult earthworms (Eisenia fetida) of mixed age were obtained from a Wildlife International, Ltd. culture that was established with earthworms obtained from the University of Maryland Wye Research and Education Center in Queenstown, Maryland. The identity of the original culture was verified by the supplier. Earthworms were from synchronous cultures (individuals not differing in age by more than four weeks) maintained in moist peat moss and fed saturated alfalfa and/or cow manure.
Adult earthworms (440 with clitellum) were transferred to the test room and held in two glass aquaria for acclimation to test conditions for 8 or more days prior to test initiation. One day prior to the test the worms were removed from the chamber and divided into ten one-liter glass beakers containing prepared artificial soil substrate adjusted to a moisture content of approximately 34% by weight, for the soil acclimation period. Earthworms were fed cow manure throughout the acclimation period.

Study design

Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
8 wk
Post exposure observation period:
not applicable

Test conditions

Test temperature:
Air temperature in the environmental room was within the desired range of approximately 20 ± 2°C with a mean air temperature of 21.1 ± 0.44°C
(mean ± standard deviation) during the test. The mean daily air temperatures in the room ranged from 20.1 to 21.9°C. Soil temperature ranged from 19.8 to 20.5°C in each of the groups at test initiation and from 20.0 to 20.9°C at test termination.
pH:
Soil pH ranged from 6.8 to 7.1 at test initiation, and from 7.1 to 7.3 at test termination.
Moisture:
Soil moisture content measured during the test ranged from 34.0 to 35.7% at test initiation and from 37.0 to 40.9% at test termination.
Details on test conditions:
TEST SYSTEM
- Test container (material, size): one-liter glass beakers covered with plastic wrap that was perforated for air exchange
- Amount of soil or substrate: 750 g/ test vessel
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 8



OTHER TEST CONDITIONS
- Photoperiod:16:8
- Light intensity: 403 -669 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Adult toxicity determined after 28 days of exposure. Repruduction was
assessed at test termination on day 56.

VEHICLE CONTROL PERFORMED: no

Nominal and measured concentrations:
Nominal soil concentrations: 0, 16.3, 29.4, 52.9, 95.3, 171, 309, 556, and 1000 mg/kg dry soil

Concentrations were verified analytically in the lowest and highest water stock solutions that were mixed with artificial soil in the test. The mean measured
concentration of the 32.6 ppm nominal water stock solution was 32.3 ppm (99% nominal). The mean measured concentration of the 2000 ppm nominal water stock solution was 2011 ppm (101% nominal). There was no measured test substance in the contol water stock solution.
Reference substance (positive control):
yes
Remarks:
carbendazin

Results and discussion

Effect concentrationsopen allclose all
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Body weight
Duration:
28 d
Dose descriptor:
LOEC
Effect conc.:
> 1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Body weight
Duration:
28 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:
56 d
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Duration:
56 d
Dose descriptor:
NOEC
Effect conc.:
566 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Duration:
56 d
Dose descriptor:
LOEC
Effect conc.:
1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Details on results:
There was less than 50% mortality of adult earthworms in the study therefore the LC50 value for mortality was determined to be greater than the
highest test concentration.
Results with reference substance (positive control):
Wildlife International, Ltd. conducted a reference toxicity test with carbendazim in 2006. The LC50 value for the mortality of the adult earthworms
exposed to carbendazim for 28 days was 7.149 mg a.i./kg dry soil, with a 95% confidence interval of 6.338 and 8.273 mg a.i./kg dry soil. There were effects upon adult earthworm weight at concentrations of 0.3 mg a.i./kg and in the 2, 4 and 8 mg a.i./kg groups. The EC50 value for reproduction
was 0.8914 mg a.i./kg dry soil, with a 95% confidence interval of 0.8416 and 0.9718 mg a.i./kg dry soil. The NOEC was 0.5 mg a.i./kg dry soil, and the LOEC was 1 mg a.i./kg dry soil, based on the numbers of juveniles produced.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
There was no mortality of adult earthworms exposed to Dowfax® 2A1 at 16.3, 29.4, 52.9, 95.3, 171, 309, 556 and 1000 mg/kg dry soil for 28
days. When compared with the control group, there were no statistically significant adverse effects upon earthworm weight in the treatment
groups during the 28-day adult exposure period. Therefore, based on body weight data, the LOEC was determined to be >1000 mg/kg and the
NOEC 1000 mg/kg. The mean number of juveniles produced in the 1000 mg/kg treatment group was statistically significantly different (p<0.05)
from the mean numbers of juveniles produced in the control group, therefore, the LOEC for reproduction was determined to be 1000 mg/kg and the NOEC 556 mg/kg dry soil.
Executive summary:

Earthworms (Eisenia fetida) were exposed to 8 different concentrations of Dowfax 2A1 and control in artificial soil for 8 weeks (56 days). Nominal concentrations of Dowfax were 0 (negative control), 16.3, 29.4, 52.9, 95.3, 171, 309, 556, and 1000 mg/kg dry soil. Concentrations of Dowfax 2A1 were analytically verified in the water stock solutions that were used to mix with the artificial soils, and these results indicated that measured concentrations were very close to nominal doses. There were four replicate vessels per Dowfax 2A1 treatment level and eight replicate test vessels in the control. Each test vessel (1 -liter beaker) was stocked with 750 g artificial soil. Ten worms were placed in each replicate vessel at test initiation. Following 28 days of exposure, adult worms were assessed for body weight and survival. Following another 28 days, juvenile production was assessed by enumerating juveniles in each test vessel. The NOEC for adult worm body weight and survival was 1000 mg/kg dw. The NOEC and LOEC for juvenile production (reproduction) was 566 and 1000 mg/kg dw, respectively.

Categories Display