Methoxycyclododecane

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Jul 1999 - 18 Feb 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control and all test concentrations after 24 and 48 h.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution of 60 mg/L was prepared by weighing the test substance into water. The solution was treated for 60 sec with an ultra-turrax at 8000 rpm and stirred for 24 h on a magnetic stirrer. To remove undissolved particles, the resulting emulsion was filtered using a filter with a pore size of 7-12 µm.
- Eluate: no
- Differential loading: no
- Controls: yes, M4-medium

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house culture at Bayer AG, Leverkusen, Germany (origin: Federal Health Office, Berlin, Germany)
- Age at study initiation (mean and range, SD): < 24 h

ACCLIMATION
- Acclimation conditions (same as test or not): same as test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

15.5 °dH

Test temperature:

19.8 - 20.1 °C

pH:

7.9 - 8.0

Dissolved oxygen:

8.6 - 8.8

Nominal and measured concentrations:

nominal: control, 0.5, 1.0, 2.0, 4.0 mg/L
measured after 0 h: < 0.3, 0.48, 0.82, 1.65, 3.26 mg/L
measured after 48 h: < 0.3, 0.43, 0.78, 1.44, 3.17 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: "Karlsruher flasks"
- Type (delete if not applicable): closed
- Fill volume: 250 - 300 mL
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mobility after 24 and 48 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.46 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.61 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: reported as geom. mean of EC0/EC100

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: 0%

Table 1: Immobilisation of Daphnia magna after 24 and 48 h

Nominal test substance concentration [mg/L]	Immobile daphnids (absolute)		Immobile daphnids [%]
	24 h	48 h	24 h	48 h
Control	0	0	0	0
0.5	0	0	0	0
1.0	4	20	20	100
2.0	20	20	100	100
4.0	20	20	100	100

Validity criteria fulfilled:

yes

Conclusions:

The test substance caused immobilisation of Daphnia magna in a guideline study according to OECD 202 (GLP). An EC50 (48 h) of 0.61 mg/L was calculated.

Description of key information

The test substance caused immobilisation of Daphnia magna in a guideline study according to OECD 202 (GLP). An EC50 (48 h) of 0.61 mg/L was calculated. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.61 mg/L

Additional information

One experimental study is available investigating the short-term effects of the test substance to aquatic invertebrates (2000). The study was performed according to the EU Method C.2 with the water flea Daphnia magna. Test concentrations of nominal 0.5, 1.0, 2.0 and 4.0 mg/L including a test medium control were tested under static test conditions. Verification of test concentrations was performed using gas chromatography. At the beginning of the study the test concentrations were 0.48, 0.82, 1.65, 3.26 mg/L. They slightly decreased to 0.43, 0.78, 1.44, 3.17 mg/L at the end of the test after 48 h. Thus, the effect concentrations were based on the arithmetic mean of measured concentrations. Immobilisation of Daphnia magna was observed after 24 and 48 h resulting in an EC50 (48 h) of 0.61 mg/L. All validity criteria were met.