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Ecotoxicological information

Toxicity to terrestrial arthropods

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Administrative data

Endpoint:
toxicity to terrestrial arthropods: short-term
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
other: rating varies from 1-2 depending on species - refer to table in results section
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
Effects and risk assessment of linear alkylbenzene sulfonates in agricultural soil. 3. Sublethal effects on soil invertebrates.
Author:
Holmstrup M. and Krogh P.H.
Year:
2001
Bibliographic source:
Environ. Toxicol. Chem. 20:1673-1679

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)
Principles of method if other than guideline:
Predacious mite test: No internationally accepted guideline is available for mite reproduction. Effects on reproduction on the predacious mite (H. aculeifer) were examined according to a method described by Krogh and Axelsen. Ten female and five male H. aculeifer (16-19 days old) were added to each test container together with 100 F. fimetaria (16-19 days old) serving as prey for the mites. Incubation and extraction of mite offspring followed the same procedure as described for springtails.
GLP compliance:
not specified
Application method:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
C10-13 LAS was obtained as an aqueous sodium salt solution with an active matter concentration of 16.1% (w/w), average molecular weight = 342 g/mol, distribution of the linear alkyl chains: C10 14%, C11 34%, C12 31%, and C13 21%; average alkyl chain length = C11.6

Sampling and analysis

Analytical monitoring:
not specified

Test substrate

Vehicle:
not specified
Details on preparation and application of test substrate:
Springtail: Twenty-seven grams dry weight of soil were mixed with 3 mL of LAS solution and filled into cylindrical test containers with lids. The bottom of the cylinder consisting of a 1-mm mesh to allow later extraction of the test animals. The mesh was covered with a layer of plastic film to prevent escape of the test animals.
Mite: A total of 54 g dry weight of soil was mixed with 6 mL of LAS solution and filled into test containers (as described for springtails).

Test organisms

Test organisms (species):
other: Folsomia fimetaria, Hypogastrura assimilis, Hypoaspis aculeifer
Animal group:
other: soil-dwelling
Details on test organisms:
Springtail: Adult, rather than juvenile, springtails were used. Ten male and ten female F. fimetaria (23-26 days old)
Mite: Ten female and five male H. aculeifer (16-19 days old)

Study design

Study type:
other: no data
Limit test:
no
Total exposure duration:
21 d

Test conditions

Details on test conditions:
A natural sandy, agricultural soil was used for all tests, rather than synthetic test soil.
Nominal and measured concentrations:
Springtail: The test concentrations were not listed but can be estimated from Figure 6 to be 0, 10, 25, 75, 275, and 800, with the numbers of adult surviving per replicate to be approximately 145, 155, 115, 110, 165, and 165 and the numbers of juveniles per replicate (reproduction) to be approximately 285, 275, 190, 145, 205, and 10.
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
21 d
Dose descriptor:
EC10
Effect conc.:
82 mg/kg soil dw
Nominal / measured:
nominal
Basis for effect:
reproduction
Remarks on result:
other: Hypoaspis aculeifer
Duration:
21 d
Dose descriptor:
EC10
Effect conc.:
100 mg/kg soil dw
Nominal / measured:
nominal
Basis for effect:
reproduction
Remarks on result:
other: Hypogastrura assimilis
Details on results:
It should be noted that these studies report worst case exposures due to the use of a sandy test soil and the fact that LAS was added as an aqueous solution to the soil. In addition, too few replicates were used for the ECx approach (e.g., <5 controls) and several key deviations from draft protocols limited the reliability of endpoints for some studies (e.g., A. caliginosa and A. longa cocoon production). Nominal concentrations were derived from tables and figures since actual values were not found in the text.

Any other information on results incl. tables

The following table shows the results of all tests.  All values are nominal LAS concentrations in mg/kg dry weight.

Species

Parameter

NOEC

LOEC

LC10 or EC10

LC50 or EC50

Relia-bility Rating

Rationale for Reliability Rating

Enchytraeus albidus

Survival, adults

Reproduction

198

20

397

40

194

6

430

41

1

1

Draft ISO/WD 16387 protocol

Aporrectodea caliginosa

Survival, adults

Cocoon production

Survival, juveniles

Growth, juveniles

278

>793

>397

278

793

>793

>397

397

329

14

>397

105

535

129

>397

354

2

3

2

2

Comparable to

ISO 11268-2

Deviations; limited cocoons

Comparable to ISO 11268-2, but with only weight measurement

Aporrectodea longa

Survival, adults

Cocoon production

Survival, juveniles

Growth, juveniles

278

>793

397

79

793

>793

793

278

329

27

296

84

535

137

517

349

2

3

2

2

Comparable to

 ISO 11268-2

Deviations; limited cocoons

Comparable to ISO 11268-2, but with only weight measurement

Folsomia fimetaria

Survival, adults

Reproduction

>793

278

>793

278

>793

85

>793

424

1

1

Comparable to  ISO 11267

Hypogastrura assimilis

Reproduction

79

278

99

421

1

Comparable to  ISO 11267

Hypoaspis aculeifer

Survival, adults

Reproduction

>793

278

>793

793

>793

82

>793

236

2

2

No guideline available

Applicant's summary and conclusion

Conclusions:
The EC10 for H. assimilis was 100 mg/kg dry weight, and the EC10 for H. aculeifer was 82 mg/kg dry weight.
Executive summary:

Groups of H. assimilis and H. aculeifer were exposed to various concentrations of test material for 21 days. At the end of this period, the number of offspring were counted. Based on reproduction, The EC10 for H. assimilis was 100 mg/kg dry weight, and the EC10 for H. aculeifer was 82 mg/kg dry weight.