Reaction mass of octan-2-ylbenzene, octan-3-ylbenzene and octan-4-ylbenzene

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Jan 2020 - 21 Feb 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

2019

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: • Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23 (2nd edition), Adopted February 08, 2019

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

During the test samples for possible analysis were taken from the control and the limit concentration, in addition, samples of all stock solutions were taken.

Frequency:
At t=0 and 72 h from freshly prepared solutions.
At 24 and t=96 h from spent solutions
At t=-2 and 1 day, from stock solutions

Volume:
10 mL from the approximate centre of the test vessels
3.0 mL from each stock solution

Storage:
Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility

Additionally, reserve samples were taken for possible analysis. If not already used, these samples were stored in a freezer (≤-15°C) for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.

Vehicle:

yes

Remarks:

hexane (evapurated)

Details on test solutions:

A stock solution of 6.0 g/lL was prepared in hexane (Merck, Darmstadt, Germany). Stocks solutions of 0.60, 6.0 and 60 mg/L were prepared by a series of dilutions of the highest stock in hexane. These stocks were used to prepare test solutions, WAFs prepared at loading rates of 0.60, 6.0 and 60 μg/L.
Fresh solutions were prepared for each renewal. Test solutions used for the exposure were prepared as follows: 3.0 or 5.0 mL of a respective stock solution was added to a 3.5- or 6.5-Liter exposure vessel, respectively. Hexane was allowed to evaporate, thereafter volumes of 3.0 or 5.0 L test medium was added to each vessel, respectively. A two-day period of magnetic stirring was applied in order to obtain the maximum soluble concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure.
The control treatment was prepared in a similar way: 5 mL of hexane was spiked into a 6.5 L exposure vessel and further treated as the remaining vessels.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Species: Carp (Cyprinus carpio, Teleostei, Cyprinidae) Linnaeus, 1758
Source: ‘De Haar Vissen’, Zodiac proefacc. Wageningen University and Research Centre, The Netherlands.
Mean length : 2.8 ± 0.3 cm
Mean weight: 0.24 ± 0.10 g
Characteristics : F1 from a single parent-pair bred in UV-treated water.
Reason for selection: This system has been selected as an internationally accepted species.
Total fish used: 20

ACCLIMATION /HOLDING
Acclimation period: At least 12 days after delivery.
Holding Medium: Test medium, adjusted ISO medium (see details of test conditions).
Measurements: Conductivity, pH, nitrate, nitrite and ammonia concentration: once a week. Temperature was continuously recorded. In addition, pH and temperature were measured before transferring the fish to the test system.
Water quality parameters: Were kept within the optimum limits for the respective fish species.
Feeding Daily with pelleted fish food (Essence 0.5-0.8 mm, Alltech Coppens International B.V., Helmond, The Netherlands)
Validity of batch In the batch of fish used for the test, mortality during the seven days prior to the start of the test was less than 5%.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

The hardness of test medium expressed as CaCO3: 180 mg/L

Test temperature:

21 - 22 °C

pH:

7.5 - 8.1

Dissolved oxygen:

6.8 - 8.1

Nominal and measured concentrations:

Nominal concentration: WAFs prepared at loading rates of 0.60, 6.0 and 60 µg/L
Measured concentration: Samples taken from the stock prepared at 60 mg/L, hexane used for preparation of the control treatment, the highest concentration and the control were analysed.
The concentrations analyzed in the samples were due to an analytical artefact e.g. integration of noise, except for one sample in which no signal was detected. All values found were below the limit of quantification (LOQ) i.e. 10 μg/L.
No test item was observed in hexane used for preparation of stock solution and treatment of the control solution. Concentration measured in the stock solutions of 60 mg/L were 64 and 89 mg/L (106 and 148% of nominal) in the first and the second renewal, respectively. Based, on these results, it was assumed that test concentrations were prepared correctly. However, exact exposure concentrations could not be provided due to a difficult nature of the test item.

Details on test conditions:

TEST SYSTEM
- Test vessel: Control and the limit concentration: 6.5 litres, all-glass, containing 5.0 litres of test solution. Lower test concentrations: 3.5 litres, all-glass, containing 3.0 litres of test solution
- Aeration: The test solutions were not aerated during the test.
- Renewal rate of test solution: Semi-static, with daily renewal of test solutions.
- No. of organisms per vessel: Control and limit concentration: 7 fish per test group. Lower concentrations: 3 fish per concentration.
- No. of vessels per concentration: 1
- Biomass loading rate: Control and the limit concentration: 0.34 g fish/Litre, i.e. 7 fish per 5 litres of test medium
Lower test concentrations: 0.24 g fish/Litre, i.e. 3 fish per 3 litres of test medium.
- Feeding: No feeding from 24 hours prior to the test and during the total exposure period.
- Introduction of fish: Within 35 minutes after preparation of the test media from a holding tank with comparable water quality parameters and pH and temperature differences between test and holding tank media of less than 1.0 unit and 1.0°C.

TEST MEDIUM / WATER PARAMETERS
The following salts (analytical grade) were added to tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
CaCl2.2H2O: 211.5 mg/L
MgSO4.7H2O: 88.8 mg/L
NaHCO3: 46.7 mg/L
KCl: 4.2 mg/L

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily

TEST CONCENTRATIONS
Based on the very low water solubility of the test item (see paragraph 4.5.1), no acute toxic effects were expected. Therefore, the study started with a combined limit/range-finding test. The limit concentration exceeded the maximum water solubility of the test item by a factor of ~2. In addition, lower concentrations spaced by a factor of 10 were tested in the combined range-finder. Based on the obtained results, no further testing was required.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 60 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: the 96h-LC50 exceeded the loading rate of 60 µg/L or the water solubility limit of the test item, i.e. was >40 µg/L.

Details on results:

- Behavioural abnormalities: No
- Other biological observations: No
- Mortality of control: No mortality or other effects were observed in the control and at any test item concentration during the exposure period.
- Other adverse effects control: no other effects observed.
- Abnormal responses: no
- Effect concentrations exceeding solubility of substance in test medium: Yes

Reported statistics and error estimates:

All calculations were based on nominal concentrations.
No LC50 could be calculated because the test item proved to be non-toxic (LC50 > maximum concentration tested).

Validity criteria fulfilled:

yes

Remarks:

"see overall remarks"

Conclusions:

In conclusion, the 96h-LC50 exceeded the loading rate of 60 µg/L or the water solubility limit of the test item, i.e. was >40 µg/L.

Executive summary:

In a 96-h acute toxicity study conducted according to OECD guideline 203, carp (Cyprinus carpio) were exposed to SHR 1396 under semi-static conditions at WAFs individually prepraed at a loading rate of 0.60 to 60 µg/L, using stocksolutions in hexane. The concentrations measured in the test solutions were below the level of quantification of the analytical method, i.e. below 0.010 mg/L. No test item was observed in hexane used for preparation of stock solution and treatment of the control solution. Concentrations measured in the stock solution of 60 mg/L were 64 and 89 mg/L (106 and 148% of nominal) in the first and the second renewal, respectively. Based on these results, it was assumed that test concentrations were prepared correctly. However, exact exposure concentrations could not be provided due to a difficult nature of the test item. No mortality or other effects were observed in the control and at any test item concentration during the exposure period.

In conclusion, the 96h-LC₅₀ exceeded the loading rate of 60 µg/L or the water solubility limit of the test item, i.e. was >40 µg/L. The study is considered to be reliable without restrictions.

Description of key information

No effects were aboserved at the loading rate of 60 µg/L or the water solubility limit of the test item, i.e. was >40 µg/L. The 96h EC50 exceeded the water solubility of the test item.

Additional information

In a 96-h acute toxicity study conducted according to OECD guideline 203, carp (Cyprinus carpio) were exposed to SHR 1396 under semi-static conditions at WAFs individually prepraed at a loading rate of 0.60 to 60 µg/L, using stocksolutions in hexane. The concentrations measured in the test solutions were below the level of quantification of the analytical method, i.e. below 0.010 mg/L. No test item was observed in hexane used for preparation of stock solution and treatment of the control solution. Concentrations measured in the stock solution of 60 µg/mL were 64 and 89 µg/mL (106 and 148% of nominal) in the first and the second renewal, respectively. Based, on these results, it was assumed that test concentrations were prepared correctly. However, exact exposure concentrations could not be provided due to a difficult nature of the test item. No mortality or other effects were observed in the control and at any test item concentration during the exposure period.

In conclusion, the 96h-LC50 exceeded the loading rate of 60 µg/L or the water solubility limit of the test item, i.e. was >40 µg/L. The study is considered to be reliable without restrictions.