Reaction Mass of Cyclohexanepropanol, 2,2,6-trimethyla-propyl-, (alpha.R,1R,6S)- and Cyclohexanepropanol,2,2,6-trimethyl-a-propyl-, [1a(S*),6b]- (9CI)

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:

From 2014-11-18 to 2014-11-29

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

GLP study conducted in compliance with OECD Guideline No. 202. Semi-stable emulsions may have been formed in the test solutions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected on June 03-05, 2013 / signed on November 05, 2013

Specific details on test material used for the study:

- Water solubility in pure water: isomer 1 = 125 µg/L; isomer 2 = 285 µg/L
- Water solubility in M4 medium: isomer 1 = 115 µg/L; isomer 2 = 261 µg/L
(determined at Dr. U.NOACK-LABORATORIEN, Noack Lab-ID: 131029FG/CWE15836)

Analytical monitoring:

yes

Details on sampling:

All concentration levels and the control were analytically verified via GC-MS at the start (0 and 24 h) and at the end of both exposure intervals (24 and 48 h).
At the start of the exposure intervals (0 and 24 h), sampling was carried out after preparation of the test concentrations.
At the end of the exposure intervals (24 and 48 h), samples were taken directly from the test vessels.
The method was validated prior to this study according to SANCO 3029/99 rev.4 (2000).

Quality criteria for the analytical monitoring:
Recoveries of the test item should be within ± 20% of the nominal or initially measured concentrations. The effect levels have to be given based on the geometric mean measured concentrations, if the initially measured concentrations differ more than 20% from the nominal concentrations or a decrease of more than 20% from the initially measured concentration is observed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The stock solution (1.00 mg/L of the test item were weighed out) was prepared with dilution water one day before the start of both exposure intervals (at -24 and 0 h). The stock solution was stirred with approximately 1100 rpm for 24 h at 25 ± 2 °C.
- Application: Per replicate, 20 g test solution were weighed out into the test vessel. This corresponds to 20 mL per test vessel. The daphnids were inserted with a small amount of dilution water (start of the exposure) or test solution (water renewal) by a pipette.
- Controls: Dilution water without test item tested under the same conditions as the test groups.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Daphnia magna STRAUS (Clone 5)
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), D-14195 Berlin, Germany.
- Breeder: DR.U.NOACK-LABORATORIEN, Käthe-Paulus-Str. 1, D-31157 Sarstedt, Germany.
- Age at study initiation: 2 to 24 h old daphnids from a healthy stock were used for the study. They were obtained by removing the juvenile daphnids from the culture vessels latest 22 h before the start of the exposure. The juveniles born within this period of max. 22 h preceding the exposure were used for the test 2 hours after separation from the culture vessels. No first brood progeny was used for the test.
- Culture: In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 ± 2°C, in an incubator, 16 h illumination, light intensity of max. 20 µE/m2/s
- Culture feeding: The culture daphnids are fed at least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata and Desmodesmus subspicatus, with an algae cell density of > 10^6 cells/mL. The algae are cultured at the test facility.
- Origin of the food algae: Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Nikolausberger Weg 18, D-37073 Göttingen, Germany.
- Feeding during test: The daphnids were not fed during the study.

ACCLIMATION
- Acclimation period: At least 2 h in dilution water

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

none

Post exposure observation period:

None

Hardness:

260 mg/L as CaCo3

Test temperature:

20.5-21.0 °C

pH:

0 h: 7.72
24 h: 7.78

Dissolved oxygen:

0 h: 8.87 mg/L
24 h: 8.77 mg/L

Salinity:

None

Nominal and measured concentrations:

Nominal concentrations: 31.3, 62.5, 125, 250, 500 and 1000 µg/L.
Corresponding geometric mean measured concentrations: 24.1, 45.9, 94.4, 212, 378 and 863 µg/L.

Details on test conditions:

TEST METHOD:
A semi-static test design with a daily renewal of the test solutions in glass flasks sealed with screw caps (made from polypropylene) under diffuse light conditions was chosen to reduce losses of the test item concentrations by evaporation.

TEST SYSTEM
- Test vessels/volume: Sealed glass flasks (4.5 (ID) x 9.5 (H) cm, ca. 130 mL) with screw caps (made from polypropylene) were used. They were filled up with the test solutions having nearly no headspace to reduce contact with air and losses of the test item concentrations by evaporation.
- Aeration: No
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable
- Renewal rate of test solution (frequency/flow rate): Not applicable
- No. of organisms per vessel: 5 (control and test material groups)
- No. of vessels per concentration (replicates): 4
- No. of vessels per vehicle control (replicates): 4
- Renewal of the test solutions: The test solutions were renewed after 24 h. For this purpose, the freshly prepared test solutions were filled into a second set of test vessels and the daphnids were transferred by a pipette.

TEST MEDIUM / WATER PARAMETERS
- Dilution water: ISO Test water, according to OECD 202
- Culture medium: Elendt M4, according to Elendt (1990), modified to a total hardness of 160 to 180 mg CaCO3/L, is used.
- Alkalinity: 260 mg CaCO3/L
- Conductivity: 647 µs

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/8 h dark cycle
- Light intensity: Diffuse light; light intensity of max. 20 µE/m2/s

EFFECT PARAMETERS MEASURED:
Biological parameters:
- Immobilisation and other observations: Immobilisation was determined in all groups after 24 and 48 h. An animal was considered to be immobile, if it was not able to swim in the water phase within 15 seconds after gentle agitation of the test vessel. Other relevant observations were not made.

Water Quality Parameters:
Dilution water: Prior to the start of the exposure (0 h) and the water renewal (24 h), the water quality parameters (i.e. pH value, dissolved oxygen concentration, temperature, conductivity and total hardness) of the dilution water were measured.
Test media: At the start of the exposure intervals (0 and 24 h), the water quality parameters of the fresh media (i.e. pH value, dissolved oxygen concentration) were measured in one additional replicate per concentration level and control. At the end of the exposure intervals (24 and 48 h), the water parameters of the old media were measured in all replicates per concentration level and control.
Temperature: The incubator temperature was recorded throughout the period of the test.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: Factor 2
- Range finding study: Test concentrations were selected based on the results of the most recent of a series of four non GLP preliminary range finding tests and the limit of water solubility of the test item in the dilution water, which was observed at approximately 1.00 mg/L. In the most recent preliminary range finding test performed under semi-static conditions with three concentrations of the test item of 10, 100 and 1000 µg/L and two replicates per concentration level with 10 daphnids each were tested in a closed system (glass flask completely filled up with the test solutions having no headspace). The percentage immobility was determined in all concentrations and control groups after 24 and 48 h of exposure.
- Results used to determine the conditions for the definitive study: After 48 h of exposure the total rate of immobilisation of daphnia was 85%, 20% and 5% at 1000, 100 and 10 µg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate p.a.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

522 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: > solubility limit

Duration:

48 h

Dose descriptor:

other: The highest tested concentration without observed effect

Effect conc.:

212 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Biological data:
Immobilization of daphnids for the definitive test was 0, 0, 0, 0, 0, 15 and 50 % (24 h); 0, 0, 0, 0, 0, 25 and 85 % (48 h) at 31.3, 62.5, 125, 250, 500 and 1000 µg/L, respectively.
- Measured Exposure Concentrations during the Definitive Test:
The measured concentrations of the test item at the start of the exposure intervals (0 and 24 h) were in the range of 81 to 98 % of the nominal values. At the end of the exposure intervals (24 and 48 h), the measured concentrations of the test item were in the range of 56 to 88 % of the nominal values. The geometric mean measured concentrations of the test item were calculated to be: 24.1, 45.9, 94.4, 212, 378 and 863 µg/L. Note that the solubility limit is measured at 376 µg/L in M4 medium according to the OECD Guideline 105 study, performed with a slow-stirring method. Therefore, toxic effects were observed at concentrations greater than the solubility limit.
- Appearance of test solutions: Semi-stable emulsions may have been formed in the test solutions. These emulsions, particularly at concentrations ≤ 1 mg/L, are generally invisible, that is why no any undissolved particles were observed.
- Water Quality Parameters:
The water quality parameters (i.e. pH-value and dissolved oxygen concentration), measured at the start (0 and 24 h) and at the end of the exposure intervals (24 and 48 h), were within the acceptable limits. The validity criteria of the test guideline were fulfilled.

Results with reference substance (positive control):

The percentage immobility for the reference item was determined after 24 h. The EC50-value with 95 % confidence limits (CI) was calculated by sigmoidal dose-response regression. The EC50-value for the most recent of the monthly performed reference tests was:
EC50: 1.57 mg/L (CI 1.53 - 1.60 mg/L)
The EC50-value of the reference item potassium dichromate after 24 h is within the prescribed concentration range of 0.6 - 2.4 mg/L of quality criteria according to AQS P 9/2 (02/2000) for daphnids clone 5 cultured in Elendt M4 medium. The EC50-value of the reference item is also within the recommended range of 0.6 - 2.1 mg/L according to OECD-Guideline 202.

Reported statistics and error estimates:

EC values and statistical analysis:
The EC50-values after 24 and 48 h were calculated by sigmoidal dose-response regression. The 95 % confidence limits were calculated from the best-fit values, the standard error and the t-distribution with the software GraphPad prism5. The concentration-effect relationships are shown graphically. The EC50 -value for the reference item and its confidence limits were calculated accordingly.

Table 6.1.3/1: Immobilisation Rates after 24 and 48 h of Exposure in the Definitive Test

 

Nominal test item concentration   [µg/L]	Geometric mean measured test item concentration [µg/L]	IMMOBILISATION [%]
		24 h					48 h
		Replicates					Replicates
		1	2	3	4	MV	1	2	3	4	MV
1000	863	60	60	40	40	50	80	80	100	80	85
500	378	0	0	60	0	15	20	0	60	20	25
250	212	0	0	0	0	0	0	0	0	0	0
125	94.4	0	0	0	0	0	0	0	0	0	0
62.5	45.9	0	0	0	0	0	0	0	0	0	0
31.3	24.1	0	0	0	0	0	0	0	0	0	0
Control		0	0	0	0	0	0	0	0	0	0

n = 20, divided into 4 replicates with 5 daphnids each

MV   = mean value

 

Table 6.1.3/2: Measured Concentrations of the Test Item during the Definitive Test (based on the determination of 3 Isomers)

 

Sampling date	2014-11-25 0 hours Start of the exposure interval		2014-11-26 24 hours End of the exposure interval		2014-11-26 24 hours Start of the exposure interval		2014-11-27 48 hours End of the exposure interval		Geometric mean measured concentration
Start of analysis	2014-11-25		2014-11-26		2014-11-26		2014-11-27
Nominal test item concentration [µg/L]	Test item
	Meas. conc. [µg/L]^1)	%	Meas. conc. [µg/L]	%	Meas. conc. [µg/L]	%	Meas. conc. [µg/L]	%	Meas. conc. [µg/L]	%
1000	949	95	858	86	981	98	694	69	863	86
500	413	83	371	74	458	92	291	58	378	76
250	230	92	220	88	219	88	181	72	212	85
125	101	81	91.0	73	123^2)	98	70.1	56	94.4	76
62.5	51.9	83	46.1	74	51.1	82	36.4	58	45.9	73
31.3	30.8^2)	98	19.8	63	26.9	86	20.4	65	24.1	77
Control	< LOQ		< LOQ		< LOQ		< LOQ		< LOQ

Meas. conc.= measured concentration of the test item, single injection, dilution factors taken into account

% = percent of the nominal concentration of the test item

LOQ = limit of quantification (10 µg test item/L)

1) Analysed on 2014-11-26

2) Reanalysed on 2014-11-27, mean value of two replicates

Table 6.1.3/3: Distribution of Isomers in the Test Item Concentrations during the Definitive Test (sum of isomers defined as 100 %)

 

Sampling date	2014-11-25 0 hours Start of the exposure interval			2014-11-26 24 hours End of the exposure interval			2014-11-26 24 hours Start of the exposure interval			2014-11-27 48 hours End of the exposure interval
Start of analysis	2014-11-25			2014-11-26			2014-11-26			2014-11-27
Nominal test item concentration [µg/L]	Distribution of Isomers of test item
	Isomer 1 [%]	Isomer 2 [%]	Sum   [%]	Isomer 1 [%]	Isomer 2 [%]	Sum   [%]	Isomer 1 [%]	Isomer 2 [%]	Sum   [%]	Isomer 1 [%]	Isomer 2 [%]	Sum   [%]
1000	49.0	51.0	100	49.9	50.1	100	51.2	48.8	100	50.3	49.7	100
500	49.0	51.0	100	50.6	49.4	100	51.0	49.0	100	50.4	49.6	100
250	49.6	50.4	100	50.8	49.3	100	49.8	50.2	100	50.6	49.4	100
125	49.8	50.2	100	51.5	48.5	100	51.6	48.4	100	50.6	49.4	100
62.5	49.2	50.8	100	49.0	51.0	100	51.1	48.9	100	50.4	49.6	100
31.3	49.4	50.6	100	50.7	49.3	100	51.0	49.1	100	50.5	49.5	100

%= percentage of the peak area of each isomer, based on the sum of peak areas defined as 100 %

 

 

Table 6.1.3/4: Calculated Concentrations of both Isomers of the Test Item during the Definitive Test

Sampling date	2014-11-25 0 hours Start of the exposure interval			2014-11-26 24 hours End of the exposure interval			2014-11-26 24 hours Start of the exposure interval			2014-11-27 48 hours End of the exposure interval
Start of analysis	2014-11-25			2014-11-26			2014-11-26			2014-11-27
Nominal test item concentration [µg/L]	Calculated Concentration for each Isomer of the Test Item*
	Isomer 1 [µg/L]	Isomer 2 [µg/L]	Sum   [µg/L]	Isomer 1 [µg/L]	Isomer 2 [µg/L]	Sum   [µg/L]	Isomer 1 [µg/L]	Isomer 2 [µg/L]	Sum   [µg/L]	Isomer 1 [µg/L]	Isomer 2 [µg/L]	Sum   [µg/L]
1000	465	484	949	428	430	858	502	479	981	349	345	694
500	202	211	413	188	183	371	234	224	458	147	144	291
250	114	116	230	112	108	220	109	110	219	91.6	89.4	181
125	50.3	50.7	101	46.9	44.1	91.0	63.5	59.5	123	35.5	34.6	70.1
62.5	25.5	26.4	51.9	22.6	23.5	46.1	26.1	25.0	51.1	18.3	18.1	36.4
31.3	15.2	15.6	30.8	10.0	9.76	19.8	13.7	13.2	26.9	10.3	10.1	20.4

*= calculated from the determined test item concentration and the percentage of isomer distribution in the test concentration

 

Validity criteria:

- In the control group, no daphnids were immobilized or showed any signs of disease or stress, e.g. discoloration or unusual behaviour such as trapping on the surface of the water, during the 48 h test period (required: not more than 10 per cent of the daphnids in the control).

- The dissolved O₂ concentration at the end of the exposure intervals was ≥ 8.01 mg/L (required: ≥ 3 mg/L at the test end of the exposure intervals) in the test vessels of all tested concentration levels and the control.

Validity criteria fulfilled:

yes

Conclusions:

No acute effects were observed after 48 hours on Daphnia magna up to the solubility limit of the test substance.

Executive summary:

Study was performed according to OECD Guideline 202 with GLP statement, to assess the 48 h-acute toxicity of the of the test substance to Daphnia magna, under semi-static conditions.

Test item was exposed to daphnids at the concentrations of 31.3, 62.5, 125, 250, 500 and 1000 µg/L for 48 hours. The no-treatment control daphnids were exposed to dilution water only. There were four replicates per treatment with five daphnids per replicate, which provided a total of twenty daphnids per each treatment and control group at test initiation. All test solutions were prepared in dilution water. The test temperature was 20.5-21.0 °C. The tested solutions were clear throughout the exposure period. Before definitive test, a 48-hour semi-static range-finding test was conducted and the percent immobilization was 85%, 20% and 5% at 1000, 100 and 10 µg/L, respectively.

 

The concentrations of the test item were analytically verified via GC-MS at the start of the exposure intervals (0 and 24 h) and at the end of the exposure intervals (24 and 48 h) in all concentration levels and the control. The measured concentrations of the test item at the start of the exposure intervals (0 and 24 h) were in the range of 81 to 98 % of the nominal values. At the end of the exposure intervals (24 and 48 h), the measured concentrations of the test item were in the range of 56 to 88 % of the nominal values. The geometric mean measured concentrations of the test item were calculated to be 24.1, 45.9, 94.4, 212, 378 and 863 µg/L. According to the water solubility study, performed in compliance with the OECD Guideline 105 with a slow-stirring method, the solubility limit measured in Daphnia medium was 376 µg/L. Therefore, semi-stable emulsions may have been formed in the test solutions. These emulsions, particularly at concentrations lower than 1 mg/L, are generally invisible, that is why no any undissolved particles were observed.

 

Immobilization of daphnids for the definitive test was 0, 0, 0, 0, 0, 15 and 50 % (24 h); 0, 0, 0, 0, 0, 25 and 85 % (48 h) at geometric mean measured concentrations of 24.1, 45.9, 94.4, 212, 378 and 863 µg/L, respectively. Therefore, toxic effects were observed only at concentrations greater than the solubility limit. The 48h-EC50 value was determined to be 522 µg/L (Cl: 457 – 607 µg/L), which is greater than the solubility limit. The EC50 -value of the reference item, potassium dichromate at 1.57 mg/L (CI 1.53 - 1.60 mg/L) after 24 h was within the prescribed concentration range of 0.6 - 2.1 mg/L.

 

In conclusion, no acute effects were observed on Daphnia magna up to the solubility limit of the test substance.

Description of key information

OECD Guideline 202, GLP, key study, validity 2:

No acute effects were observed on Daphnia magna up to the solubility limit of the test substance.

Additional information

To assess the short-term toxicity of the registered substance to aquatic invertebrates, one valid study is available.

This GLP study, assessed as a key study, was performed on the registered substance according to OECD Guideline 202. Twenty Daphnia magna were exposed to each concentration level of the test substance (nominal concentrations: 31.3, 62.5, 125, 250, 500 and 1000 µg/L) and the control, in closed system (sealed glass flasks) under semi-static conditions, over a period of 48 hours. The concentrations of the test substance were analytically verified via GC-MS at the start of the exposure intervals (0 and 24h) and at the end of the exposure intervals (24 and 48h) in all concentration levels and the control. The measured concentrations of the test substance at the start of the exposure intervals were in the range of 81 to 98 % of the nominal values. At the end of the exposure intervals, the measured concentrations of the test substance were in the range of 56 to 88 % of the nominal values. Therefore, the geometric mean measured concentrations of the test substance were calculated to be: 24.1, 45.9, 94.4, 212, 378 and 863 µg/L. According to the water solubility study, performed in compliance with the OECD Guideline 105 with a slow-stirring method, the solubility limit measured in Daphnia medium was 376 µg/L. Therefore, semi-stable emulsions may have been formed in the test solutions. These emulsions, particularly at concentrations lower than 1 mg/L, are generally invisible, that is why no any undissolved particles were observed. Immobilization of daphnids for the definitive test was 0, 0, 0, 0, 0, 15 and 50 % (24 h); 0, 0, 0, 0, 0, 25 and 85 % (48 h) at geometric mean measured concentrations of 24.1, 45.9, 94.4, 212, 378 and 863 µg/L, respectively. According to this result, toxic effects were observed only at concentrations greater than the solubility limit. The first effects (25% immobilisation at 48 h) were observed at a geometric mean concentration of 378 µg/L, just above the solubility limit. The 48h-EC50 value was determined to be 522 µg/L (Cl: 457 – 607 µg/L), which is significantly greater than the solubility limit.

In conclusion, no acute effects were observed on Daphnia magna up to the solubility limit of the test substance.