4,4a,5,9b-tetrahydroindeno[1,2-d]-1,3-dioxin

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:

10 Aug 1999 - 12 Aug 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

analytical measurements based on TOC only

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 test concentration at test start and after 48 h.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was weighed directly into test water, treated for 1 h in an ultra-sonic bath and afterwards stirred with a magnetic stirrer for 24 h.
- Eluate: no
- Differential loading: yes
- 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:

yes

Total exposure duration:

48 h

Hardness:

15.1 °dH

Test temperature:

20.4 - 20.5 °C

pH:

8.0

Dissolved oxygen:

8.5 - 8.7 mg/L

Nominal and measured concentrations:

nominal: control, 100 mg/L
measured after 0 h: 2, 73 mg/L
measured after 48 h: 3, 73 mg/L
All values refer to TOC determinations. According to the relevant product information, 1 mg/1 TOC equals to 1.3 mg/1 of the test substance (structural formula: C11-H12-02; molecular weight: 176.23 g/mol).

Details on test conditions:

TEST SYSTEM
- Test vessel: cylindrical test vessels (diameter 4.0 cm, height 6.4 cm)
- Fill volume: 20 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 (M4 medium)
- 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

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 94.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 94.9 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
100	0	0	0	0

The test results refer to the concentrations calculated from the measured TOC values. According to the relevant product information, 1 mg/L TOC equals to 1.3 mg/L of the test substance.

The EC50 (48 h) is not reported in the study report. However, it was derived based on the raw data presented in table 1.

Validity criteria fulfilled:

yes

Conclusions:

No immobilisation of Daphnia magna was observed in a guideline study according to EU Method C.2 (GLP). Hence, the EC50 (48 h) was derived to be > 100 mg/L (nominal).

Executive summary:

The study was performed according to the EU Method C.2 with the water flea Daphnia magna. A limit test concentration of 100 mg/L was tested under static conditions. The actual test substance concentration was verified by TOC-analysis at the beginning and at the end of the exposure period. 73 mg TOC/L were measured at both sampling points. 1 mg TOC/L equals to 1.3 mg test substance/L. Thus, the test substance was found in the test solutions at a concentration of 94.9 mg/L. Immobilisation of D. magna was not observed after 48 h resulting in an EC50 (48 h) of > 100 mg/L (nominal) and > 94.9 mg/L (arithmetic mean of measured concentrations). All validity criteria were met.

Description of key information

No immobilisation of Daphnia magna was observed at the limit concentration of 100 mg/L in a guideline study according to EU Method C.2 (GLP). Hence, the EC50 (48 h) was derived to be > 100 mg/L (nominal).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

One experimental study is available investigating the short-term effects of the test substance to aquatic invertebrates (1999). The study was performed according to the EU Method C.2 with the water flea Daphnia magna. A limit test concentration of 100 mg/L was tested under static conditions. The actual test substance concentration was verified by TOC-analysis at the beginning and at the end of the exposure period. 73 mg TOC/L were measured at both sampling points. 1 mg TOC/L equals to 1.3 mg test substance/L. Thus, the test substance was found in the test solutions at a concentration of 94.9 mg/L. Immobilisation of D. magna was not observed after 48 h resulting in an EC50 (48 h) of > 100 mg/L (nominal) and > 94.9 mg/L (arithmetic mean of measured concentrations). All validity criteria were met.