Oct-7-en-1-ol

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 April 2022 - 14 April 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted: 2004-04-13

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Sample Preparation
No Enrichment
2 g NaCl were added to 10 mL of the test item solution from the concentrations 22 mg/l, 46 mg/L and 100 mg/L; then, the clear solution was extracted two times with the solvent di-chloromethane (2 x 4 mL), the organic phase was collected into a 10 mL flask, after drying with Na2SO4. The flask was filled up to 10 mL with dichloromethane after addition of 500 µL ISTD (internal standard) stock solution (1000 mg/L in dichloromethane) and the solution was measured via GC/MS.

Tenfold Enrichment
6 g NaCl were added to 100 mL of the test item solution from the concentrations 4.6 mg/L and 10 mg/L as well as the blank control; then, the clear solution was extracted two times with the solvent dichloromethane (2 x 4 mL), the organic phase was collected into a 10 mL flask, after drying with Na2SO4. The flask was filled up to 10 mL with dichloromethane after addition of 500 µL ISTD (internal standard) stock solution (1000 mg/L in dichloromethane) and the solution was measured via GC/MS.

Details on test solutions:

A stock solution containing 99.7 mg/L test item in M4 medium was prepared. For this the amount of 118 µL/L (based on a density of 0.84453 g/cm³ at 20 °C, provided by the sponsor) was pipetted in a decanting bottle, filled with the respective amount of M4 medium. This solution was stirred on a magnetic stirrer under closed conditions for 1 hour, to guarantee complete dissolution. The lower treatments (46 / 22 / 10 / 4.6 mg/L nominal) were prepared by dilution of this stock solution with M4 medium.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna Straus
- Strain, Daphnia magna (Crustacea, Arthropoda) (Straus / BERLIN)
- Age at study initiation: between 0 and 24 hours
- Method of breeding: In-house breeding since 27. September 2007
- Source: Daphnia magna is bred in the LAUS GmbH throughout the year.

19.75 hours before the start of the test, the adult animals were separated from the young. 1 hour before test start, the adults were caught with the help of a glass tube, and the new-born daphnia (age < 24h) were sieved from the medium and immediately placed into a beaker containing M4 medium. After the settling-in period, animals which showed no ap-parent damage were used for the test.

Test type:

static

Water media type:

other: ELENDT M4 Medium

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Closed system

Test temperature:

19.6 – 20.2 °C

pH:

Control: 7.6 – 7.8
Treatments: 7.4 – 7.9

Dissolved oxygen:

Control: 8.5 – 9.0 mg/L
Treatments: 7.4 – 7.9 mg/L

Conductivity:

Photo period: 16/8 hours, using LED’s

Nominal and measured concentrations:

4.6 / 10 / 22 / 46 / 100 mg/L nominal concentration

Details on test conditions:

Experimental Conditions
Treatments: 4.6 / 10 / 22 / 46 / 100 mg/L nominal concentration
The concentrations to be tested were based on the result of a non-GLP pre-test.
Observation times: 24 and 48 hours
Medium renewal: none
Replicates (Treatments): 4 vessels, each completely filled with test solution and 5 daphnia
Replicates (Blank control): 4 vessels, each completely filled with M4 medium and 5 daphnia

Study Performance
Using a glass tube, the daphnia were caught and lifted from the beaker. They were put on a small sieve, and the medium surrounding the animals was sucked off using absorbent paper. Immediately after that, the animals were put into the respective test solution.
The test vessels were left to stand for 48 hours. After 24 and 48 hours, the immobilised daphnia were counted. Daphnia are considered immobilised when they do not perform any movements or are only able to move their antennae when the beaker is gently agitated. Daphnia which are trapped at the surface of the test solution are also considered immobilised

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorphenol (C6H4Cl2O, CAS No. 591-35-5) was used as positive control in a current reference study to assure that the test conditions are reliable.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

23.84 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Mobility of Control:
None of the animals were immobilised in the blank control

Results with reference substance (positive control):

3,5-Dichlorphenol (C6H4Cl2O, CAS No. 591-35-5) was used as positive control in a current GLP reference study (202204R201) in March 2022. The 48h-EC50 against 3,5-Dichlorphenol was determined as 2.04 mg/L

Findings:

Immobility

The three highest tested concentrations (22, 46 and 100 mg/L nominal) showed toxicity between 15 and 100 % immobilisation at the end of the test. None of the animals were immobilised in the blank control and the two lowest tested concentrations (4.6 and 10 mg/L).  

The determined immobility is listed in the following table:

Nominal Concentration in mg/L	Immobility 24 hours					Immobility 48 hours
	absolute				in %	absolute				in %
Blank control	0	0	0	0	0	0	0	0	0	0
4.6	0	0	0	0	0	0	0	0	0	0
10	0	0	0	0	0	0	0	0	0	0
22	0	0	0	0	0	2	1	0	0	15
46	4	3	0	3	50	5	5	5	5	100
100	4	5	4	4	85	5	5	5	5	100

 

 

 

pH and O₂

The pH values and the concentration of dissolved oxygen in the treatments and the blank control are given in the following table.

Nominal Concentration in mg/L	pH		O2-Concentration in mg/L
	0 h	48 h	0 h	48 h
Blank control	7.8	7.6	9.0	8.5
4.6	7.8	7.4	8.9	7.8
10	7.9	7.4	8.9	7.6
22	7.9	7.4	8.9	7.6
46	7.9	7.4	8.8	7.3
100	7.9	7.5	8.8	7.7

Analytical Determination

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using GC-determination. The measured concentrations lay between 99 % and 106 % of the nominal concentrations at the beginning of the test and between 67 % and 92 % of the nominal concentrations at the end of the test. Therefore, the determination of the results was based on the geometric mean of the measured concentrations.

Because at the end of the test, the measured concentration of the lowest tested concentration 4.6 mg/L lay below LOQ, ½ LOQ (2.3 mg/L) was used to calculated the geometric mean for this concentration (see OECD guidance document No. 23 § 165).

The measured concentrations for treatment and blank control are given in the following table.

% of Nominal Concentration and Geometric Mean

Nominal Concentration	% of Nominal Concentration		Geometric Mean of measured concentrations
mg/L	0 h	48 h	mg/L
Blank control	--	--	--
4.6	101	67	3.3*
10	99	79	8.8
22	105	86	20.8
46	106	92	45.4
100	101	90	95.3

* For the measured value at the end of the test, ½ LOQ (2.3 mg/L) was used to calculate the geometric mean for this concentration.

Validity criteria fulfilled:

yes

Remarks:

• Immobilisation in the controls may not exceed 10 %. Immobilisation in the control was 0 %. • The concentration of dissolved oxygen at the end of the test must be at least 3 mg/L. The lowest concentration of dissolved oxygen at the end of the test was 7.

Conclusions:

One valid experiment was performed.
The study was performed using 5 concentrations ranging from 4.6 to 100 mg/L nominal concentration. For each test concentration and the blank control, 20 daphnia were exposed to the test item for 48 hours in a closed static test system. After 24 and 48 hours, the immobilised daphnia were counted.
The three highest tested concentrations (22, 46 and 100 mg/L nominal) showed toxicity between 15 and 100 % immobilisation at the end of the test. None of the animals were immobilised in the blank control and the two lowest tested concentrations (4.6 and 10 mg/L).
3,5-Dichlorphenol (C6H4Cl2O, CAS No. 591-35-5) was used as positive control in a current reference study to assure that the test conditions are reliable.

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using GC-determination. The measured concentrations were between 99 % and 106 % of the nominal concentrations at the beginning of the test and between 67 % and 92 % of the nominal concentrations at the end of the test. Therefore, the determination of the results was based on the geometric mean of the measured concentrations.
Because at the end of the test, the measured concentration of the lowest tested concentration 4.6 mg/L was below LOQ, ½ LOQ (2.3 mg/L) was used to calculated the geometric mean for this concentration (in accordance with OECD guidance document No. 23 § 165).

No observations were made which might cause doubts concerning the validity of the study outcome. All validity criteria were met.
The result of the test is considered valid.

Description of key information

The toxicity of the test item OEA was examined in an acute daphnia test according to OECD 202 and under GLP conditions. The exposure was confirmed using GC/MS determination. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Remarks:

48h

Effect concentration:

23.82 mg/L

Additional information

The result of the key study is supported by the results of a second acute daphnia test (also performed according to OECD 202 and under GLP conditions). In this study the EC50 (48h) was concluded to exceed 50 mg/L (based on nominal values).