Reaction mass of (1S*, 2R*, 5S*)-2-Isopropenyl-5-methylcyclohexanol and (1S*, 2S*, 5R*)-2-Isopropenyl-5-methylcyclohexanol

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:

12 -14 Sep 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: All test concentrations were sampled after 0 and 48 h.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution was prepared to prepare the test solutions. 119.9 mg of the test substance were added to 1 L of dilution water and treated for 60 sec with an ultra-turrax and afterwards stirred 24 h an a magnetic stirrer.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Feeding during test: None

ACCLIMATION
- Acclimation conditions: A population of parthenogenetic females is maintained in the test facility under constant temperature conditions (20 ± 1 °C) at a 16 : 8 h light-dark photoperiod (illumination: < 1000 lux). The culture water (M4 medium) is partly renewed once a week. Mortalities of parent Daphnia during the culture period are recorded daily in a semi-quantitative way. The neonates are separated from their parent Daphnia by filtration prior to the test.
- Type and amount of food: The Daphnia are exclusively fed with unicellular green algae (Scenedesmus subspicatus CHODAT) 'ad libitum'.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

15.5 °dH (= 276.7 mg/L CaCO3)

Test temperature:

20.0 - 20.4 °C

pH:

7.6 - 7.9

Dissolved oxygen:

93.3 - 95.0% saturation

Nominal and measured concentrations:

Nominal: control, 24.6, 49.7, 98.9 mg/L
Measured (TOC after 0 h): < 2 mg/L, 23.4 mg/L, 46.8 mg/L, 93.6 mg/L
Measured (TOC after 48 h): < 2 mg/L, 22.1 mg/L, 41.6 mg/L, 88.4 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beakers (fill volume: 20 mL, headspace: 30 mL)
- Aeration: none
- 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: same as test
- Intervals of water quality measurement: after 0 and 48 h

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

EFFECT PARAMETERS MEASURED
- Mobility and behaviour was investigated after 24 and 48 h.

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

45.5 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Geometric mean of EC0/EC100

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

22.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

91 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Immobilisation in control: 0%

Table 1: Immobilisation of D. magna during the study

Nominal concentration	% immobilisation
	24 h	48 h
Control	0	0
24.6 mg/L	0	0
49.7 mg/L	0	65
98.9 mg/L	75	100

Table 2: TOC measurement: Nominal concentration 24.6 mg/L

Chemical analysis	0 h	48 h
TOC values [mg/L]	18	17
Equivalent to test substance [mg/L]	23.4	22.1

Table 3: TOC measurement: Nominal concentration 49.7 mg/L

Chemical analysis	0 h	48 h
TOC values [mg/L]	36	32
Equivalent to test substance [mg/L]	46.8	41.6

Table 4: TOC measurement: Nominal concentration 98.9 mg/L

Chemical analysis	0 h	48 h
TOC values [mg/L]	72	68
Equivalent to test substance [mg/L]	93.6	88.4

Validity criteria fulfilled:

yes

Conclusions:

The test substance caused immobilisation of Daphnia magna in a guideline study according to EU Method C.2 (GLP). An EC50 (48 h) of 45.5 mg/L was calculated as geometric mean of EC0 and EC100, based on arithmetic mean of measured concentrations.

Description of key information

EC50 (48 h): 45.5 mg/L (geometric mean of EC0/EC100)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

45.5 mg/L

Additional information

One experimental study is available investigating the toxicity of the test item to aquatic invertebrates according to EU Method C.2 under GLP conditions (2000). Daphnia magna was exposed for 48 h to nominal concentrations of 24.6, 49.7 and 98.9 mg/L under static conditions. The actual test concentrations in the test medium were verified by analysis of the total organic carbon (TOC) content. TOC measurements resulted in concentrations of 23.4 mg/L, 46.8 mg/L, 93.6 mg/L at test start and 22.1 mg/L, 41.6 mg/L, 88.4 mg/L after 48 h.
100% immobilization was recorded at the highest concentration of 98.9 mg/L whereas 0% immobilization resulted at nominal 49.7 mg/L. Thus, the EC50 was calculated as geometric mean of EC0 and EC100 resulting in 45.5 mg/L based on arithmetic mean of measured concentrations.