Registration Dossier

Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:
toxicity to soil macroorganisms except arthropods: short-term
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1984

Materials and methods

Principles of method if other than guideline:
No guideline specified, cf. "Any other information on material and methods" for details.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Specific details on test material used for the study:
The source and general characteristics of the used organic chemicals were at least 98% purity. Chemicals were purchased from Aldrich Chem. Co., Milwaukee, WI, Eastman Kodak Co., Rochester, NY, and Fisher Scientific Co., Fairlawn, NJ.

Test organisms

Test organisms (species):
Eisenia fetida
Animal group:
annelids
Details on test organisms:
The worm were grown in the laboratory at room temperature (20-22° C) on a consistent organic food source, horse (equus caballus) manure. Care was taken, that manure from medicated animals was not used.

Study design

Study type:
laboratory study
Substrate type:
other: filter paper (contact test), artificial soil (artificial soil test)

Test conditions

Test temperature:
20° C
pH:
6.0 +/- 0.5 (artificial soil test)
Moisture:
35% (artificial soil test)
Reference substance (positive control):
yes

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
1 050 - 1 750 other: µg/cm²
Basis for effect:
mortality
Remarks:
contact test

Any other information on results incl. tables

Table 1 lists the indiviuals LC50 values and 95% confidence intervals for the 44 chemicals tested in the contact tests, their slubility and vapor pressure. Table 2 lists the combined values lists the combined values for 6 groups of chemicals evaluated in the contact tests, in the order of the most toxic group (phenols) to the least toxic group (phthalates).

Table 3 identifies the 10 most toxic and the 10 least toxic organic chemicals as determined by the contact tests. The 10 least toxic chemicals included five phthalates.

The phthalates, the least toxic chemical group tested, are very low in solubility and vapor pressure. A brief comparison of the tested chemicals suggests that compounds, that have the least toxicity to earthworms, are those that are not very soluble in water or have a high water pressure.

The lower the molecular weight of the phthalate compound, the greater toxicity in the contact tests (Table 1). Toxicity could be related to solubility, since the more soluble phthalates were the more toxic chemicals.

In the artificial soil tests the phthalates were one of the least toxic chemicals tested.

Applicant's summary and conclusion

Conclusions:
A mean LC50 of 1360 µg/cm² was established.
Executive summary:

Two test methods, the 2d contact test and the 14d artificial soil test, were used to evaluate the impact of six major classes of organic chemicals on the earthworm (eisenia fetida). Of the organic chemicals tested phenols and amines were the most toxic to the worm, followed in descending order of toxicity by the substituted aromatics, halogenated aluphaties, polycyclic aromatic hydrocarbons and phthalates.