Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD 202, part 2 (1984)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
3,3,5-trimethylcyclohexanol of Hüls AG, purity 98.7 % (GC-FID area). Produced 21 August 1992; Sample No. 1346/920925; Sample ID 3633/81 458

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
MONITORING OF TEST SUBSTANCE CONCENTRATION
- days 0, 12, and 19 (fresh solutions) and 2, 14, and 21 (before renewal or end).
- DOC deterimination

Test solutions

Vehicle:
no
Details on test solutions:
STOCK AND TEST SOLUTION AND THEIR PREPARATION
- Dilution water: M4 medium (Elendt, 1990)
- Test item concentration in stock solution: 0.1 g/l

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISMS
- Strain: Daphnia magna, clone 5 - Source/supplier: Hüls AG (inhouse)
- Breeding method: In M4 medium (Elendt, 1990), water renewal each 2-3  days, isolation of offspring for further breeding each aaprox. 4 weeks
- Age: < 24 hours on day 0
- Feeding: Scenedesmus subspicatus, daily as much as consumed
- Pretreatment: Removal of adults 24 h prior to testing

Study design

Test type:
semi-static
Water media type:
freshwater
Total exposure duration:
21 d

Test conditions

Test temperature:
- Test temperature: 21 +- 1 °C
pH:
7.6-8.3 (1 determination per concentration on days 2, 5, 12, 14, 19, and 21)
Dissolved oxygen:
91-103 % saturation (1 determination per concentration on days 2, 5, 12, 14, 19, and 21)
Nominal and measured concentrations:
Nominal/measured concentrations (DOC): 
6 / 12 / 25 / 50 / 100 mg/l nominal
6 / 12 / 25 / 47 /  94 mg/l mean of measured (fresh solutions)
5 / 11 / 20 / 34 /  73 mg/l measured, day 2
5 / 10 / 21 / 42 /  75 mg/l measured, day 14
4 /  9 / 22 / 44 /  87 mg/l measured, day 21
Details on test conditions:
DILUTION WATER
- Synthetic freshwater according to Elendt (1990)

TEST CONDITIONS
- Feeding during test: daily with Scenedesmus subspicatus, days 0-6: 5.0E+06 cells/animal daily, days 7-21: 1.0E+07 cells/animal daily
- Control group: feeding as above, no test substance
- Photoperiod: 16 hours 1000 Lux / 8 hours 100 Lux

TEST SYSTEM
- Renewal of test solution: Each Monday, Wednesday, and Friday - Exposure vessel type: 150 ml beakers with approx. 80 ml test solution - Number of replicates, individuals per replicate: 10 replicates + 2  spare replicates (to substitute males if required) with 1 individual each

EFFECT PARAMETERS MEASURED
- mortality, number of juveniles (reproduction rate)

Results and discussion

Effect concentrationsopen allclose all
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
25 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Duration:
21 d
Dose descriptor:
LOEC
Effect conc.:
50 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Details on results:
The analytical values were close to nominal (within +- 20 % except for stability control at >= 50 mg/l). Thus the evaluation was based on nominal 
concentrations. 

Any other information on results incl. tables

- Effect data (Immobilisation and reproduction): 
  --------------------------------------------------------
  Concentration   Mortality   Offspring/adult   Inhibition
  --------------------------------------------------------
    0 mg/l             0 %      64 +- 10            0 %
    6 mg/l            10 %      66 +- 10           -4 %
   12 mg/l             0 %      67 +- 14           -6 %
   25 mg/l             0 %      67 +-  9           -5 %
   50 mg/l             0 %      39 +- 18           39 % *
  100 mg/l            40 %       5 +-  4           93 % *
  --------------------------------------------------------
  * significant
- Other effects: The change in pH value from fresh to used test solution  was 

> 0.3 in one case (100 mg/l: 8.7 on day 12, 8.1 on day 14). This had  no effect 

on the result and thus on the validity of the study.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

The long-term effects of 3,3,5 -trimethylcyclohexanole on the reproduction rate and the mortality of Daphnia magna were investigated in a semi-static test over a period of 21 days by Hüls AG (1994). The study was conducted according to OECD 202, part II (1984). Five concentrations ranging from 6 to 100 mg/L (nominal concentrations) were tested. No effects on the reproduction rate of Daphnia magna were observed at 25 mg/L (NOEC) and below. The lowest concentration at which a reduction in reproduction occured was 50 mg/L (LOEC). Effects on the mortality of the parent animals was observed at 100 mg/L (40% mortality after 21 days).

NOEC (reproduction): 25 mg/L

LOEC (reproduction): 50 mg/L

The study was assessed as "reliable without restrictions".