Reaction mass of rel-(2S,4R,6S)-2,4,6-trimethyl-4-phenyl-1,3-dioxane and rel-(2S,4S,6S)-2,4,6-trimethyl-4-phenyl-1,3-dioxane

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:

21 Sep 1999 - 23 Sep 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

only three concentrations tested, analytical measuremens 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 all test concentrations at test start and after 48 h.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution of 120 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 1 h on a magnetic stirrer.
- Eluate: no
- Differential loading: no
- Controls: yes, M4-medium

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- 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:

15.4 °dH

Test temperature:

20.0 - 20.3 °C

pH:

8.2

Dissolved oxygen:

5.8 - 5.9 mg/L

Nominal and measured concentrations:

nominal: control, 25, 50, 100 mg/L
measured after 0 h: < 2, 20, 40, 79 mg/L
measured after 48 h: < 2, 21, 40, 77 mg/L

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 abter 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.:

26.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

52 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.:

101.4 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
25	0	0	0	0
50	0	4	0	20
100	16	20	80	100

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.

Validity criteria fulfilled:

not applicable

Conclusions:

This study resulted in an EC50 (48 h) of 52 mg/L based on mobility of D. magna (EU method C.2, GLP).

Description of key information

EC50 (48 h): 52 mg/L based on immobilisation of D. magna (EU Method C.2).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

52 mg/L

Additional information

One experimental study is available investigating the short-term effects of the substance to aquatic invertebrates. The study was performed according to the EU Method C.2 (GLP) with the water flea Daphnia magna. Nominal concentrations of 25, 50 and 100 mg/L were tested under static conditions. Test concentrations were verified by TOC-analysis at the beginning and end of the exposure period. The measured concentration dropped slightly below 80% at the highest test concentration (77% after 48 h at 100 mg/L). Immobilisation of D. magna was observed after 48 h resulting in an EC50 (48 h) of 52 mg/L based on the geometric mean of measured concentrations.