COASOL 290 PLUS

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2018

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)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Name: COASOL 290 PLUS
Chemical name: Reaction mass of dibutyl adipate and dibutyl glutarate
Batch/Lot Number: 6H04163A01
Description: Clear colourless liquid
Purity: 99.3 %
Expiry date: 04 August 2019
Storage condition: Room temperature (15-25 °C, ≤ 70 RH%)
Safety precautions: Routine safety precautions (gloves, goggles, face mask, lab coat) for unknown materials were applied to assure personnel health and safety.

Analytical monitoring:

yes

Details on sampling:

Samples were taken at all concentrations as well as from the control, at the beginning and at the end of the renewal periods.

Vehicle:

yes

Details on test solutions:

The test solutions were prepared using a saturated solution method (water accommodated fraction, WAF) according to the Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, OECD No. 23 (2000). Test item solutions (nominal loading rates of 1.25, 2.5, 5.0, 10.0 and 20.0 mg/L) were prepared individually by dispersing/dissolving the amount of test item into the test medium (ISO Medium) two days before the start of the experiment. These solutions were shaken for about 24 hours at approximately 30°C and then equilibrated for about 24 hours at approximately 20°C. The non-dissolved test material was removed by filtration through a fine (0.22 µm) filter to give the appropriate WAF solutions. The test solutions were prepared just before introduction of the Daphnia (start of the treatments). Prior to treatment of each renewal period, test item solution was prepared by the method described above.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species and strain: Daphnia magna
Source: István Szent University, 2100 Gödöllő, Páter Károly u. 1, Hungary
Breeding The Daphnia are bred in Ecotoxicological Laboratory of Charles River Laboratories Hungary Kft. (formerly Citoxlab Hungary Ltd.).
The health of the stock animals is continuously monitored by visual daily checking. Abnormal behaviour or significant decrease of population is recorded.
Justification of strain: Daphnia magna is the standard species of the acute immobilisation test.
Number of animals: There were 20 animals in test group and control group respectively, divided into 4 replicates (5 animals / replicate)
Age of the animals: They were less than 24 h old at the beginning of the test
Acclimatization: There was no acclimatization because the water used was similar to the culture water.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

The reconstituted water (ISO medium) had a total hardness of 247 mg/L (as CaCO3).

Test temperature:

The water temperature was measured at the start and at the end of the renewal periods in each test vessel. The test temperature was in the range of 20.5– 20.9°C measured in the test vessels. The additionally measured temperature in the climate chamber was between 20.2 and 21.1°C.

pH:

The pH of the test solution was not adjusted and not varied by more than 1.5 units in any one test. The pH was measured at the start and at the end of the renewal periods in each test vessel and was in the range of 7.40 – 7.84.

Dissolved oxygen:

The dissolved oxygen concentration was measured in each test vessel at the start and at the end of the renewal periods and was in the range of 7.1 – 8.9 mg/L.

Nominal and measured concentrations:

Because significant immobility was observed at the higher concentration levels during the preliminary range-finding test, five test concentrations and one control were used in the main test under semi-static conditions. The nominal concentrations of test item used in the main experiment were:1.25, 2.5, 5.0, 10.0 and 20.0 mg/L nominal loading rates WAFs.

Details on test conditions:

The test duration was 48 hours. Twenty animals, divided into four groups (glass beakers) of five animals each (at least 5 mL test solution/animal) were used at the test concentrations and for the control group as well under semi-static conditions. The test was performed under semi-static conditions. The frequency of the water renewal periods was 24 hours. The choice of the test concentration was made on the basis of the results of the preliminary range-finding test.

The concentration range-finding test was conducted to determine the approximate toxicity of the test item so that appropriate test concentrations could be selected for use in the definitive test. Ten daphnids (divided into two replicates) in each test concentration and control were exposed for 48 hours under semi-static conditions. The concentration levels used and results (48 h) of the preliminary range-finding test are summarized in the following tables.

Results of the Preliminary Range-Finding Test:
Nominal concentrations
[mg/L nominal loading rate WAF] Untreated control 0.1 1 10 100
Number of
treated / immobilised animals 10 / 0 10 / 0 10 / 0 10 / 7 10 / 10

The immobility or mortality of the Daphnia was determined by visual observation 24 and 48 hours after the start of the test. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker are considered to be immobile. The number of immobilised animals and the percentage of immobility were determined at 24 and 48 hours. The water temperature, the oxygen concentrations and pH of the control and the test solutions were measured at the beginning and at the end of the renewal periods.

Reference substance (positive control):

yes

Remarks:

For the evaluation of the quality of the Daphnia clone and the experimental conditions, potassium dichromate is tested at least twice a year. Last testing date: 19- 20 June 2018. The 24h EC50: 0.71 mg/L, (95 % confidence limits: 0.66 – 0.76 mg/L).

Key result

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

10.29 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

5.16 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EL100

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

2.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Executive summary:

The acute toxicity of COASOL 290 PLUS on Daphnia magna was assessed in an acute immobilisation test, over an exposure period of 48 hours in a semi-static test system. Because significant immobility was observed at the highest examined concentration level during the preliminary range-finding test, five test concentrations and one control group were tested in the definitive test under semi-static conditions. The nominal concentrations of test item used in the main experiment were: 1.25, 2.5, 5.0, 10.0 and 20.0 mg/L nominal loading rates WAFs. The test item was supplied as a reaction mass of dibutyl adipate and dibutyl glutarate. The test item was not fully soluble at all tested concentrations, hence a WAF method was used to produce a range of concentrations at nominal loading rates from 1.25 to 20.0 mg/L. As is typical for WAF studies with substances described as a ‘reaction mass’ it was not known in advance what fractions of the supplied substance may be soluble or may be toxic, hence a general analytical method was used to measure the total organic carbon per mL aquatic media (TOC). The biological results are reported in units of the nominal loading rates; the TOC results are considered to be supporting data, confirming exposure. The biological results are based on the nominal loading rates (WAFs). Twenty animals, divided into four groups (glass beaker) of five animals each were used at the test concentrations and for the control as well. The 24 and 48 hours EL50valuesof the test item were calculated using Probit analysis by TOXSTAT software. The 48h EL100 values of the test item were determined directly from the raw data. For the determination of the LOELR and NOELR, the immobilization at the test concentrations was tested on significant differences to the control values by Dunnett’s Test using TOXSTAT software. All validity criteria were met during this study.

 

Under the conditions of this Daphnia magna acute immobilisation study the observed endpoints for the effect of COASOL 290 PLUS were the followings:

 

Calculation based on the nominal loading rates (WAFs):

- The 24h EL50value:          10.29 mg/L (95 % conf. limits: 9.02 – 11.73 mg/L)

- The 48h EL50value:          5.16 mg/L (95 % conf. limits: 4.77 – 5.58 mg/L)

- The 48h EL100value:        20.0 mg/L

- The 48h No-Observed Effect Loading Rate (NOELR):  2.5 mg/L

- The 48h Lowest Observed Effect Loading Rate (LOELR):  5.0 mg/L

 

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ISO TC147/SC5/WG2 Water Quality, Determination of the acute lethal toxicity to marine copepods (Copepoda, Crustacea)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
None

Analytical monitoring:

yes

Details on sampling:

Water samples from each of the control and test groups (10, 18, 23 56 and 100 mg/L) were collected at 0 and 48 hours for quantitative analysis. Duplicate samples taken and stored at -20 Deg C for futher analysis as necessary.

Vehicle:

no

Details on test solutions:

Amounts of test material (100, 180, 320, 560, and 1000 mg) were each seperately added to the surface of 10L of synthetic sea water to give the 10, 18, 32, 56, and 100 mg/L loading rates, respectively. After the addition of the test material, the synthetic sea water was stirred by magnetic stirring using a stir rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixtures allowed to stand for 1 hour. A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through teh Nescofilm seal. The aqueous phase or WAF was removed by mid-depth siphoning (the first 75-100 ml discarded) to give the 10, 18, 32, 56, and 100 mg/L loading rate WAFs. Microscopic inspection of the WAFs showed no micro-dispersions or undissolved test material to be present.

Test organisms (species):

other aquatic crustacea: Acartia tonsa

Details on test organisms:

Acartia tonsa aged 12 -14 days supplied by Guernsey Sea Farms, Vale, Guernsey, UK. Prior to dispatch were held at 20 +/- 1 degrees Celsius in sea water with a salinity of 33 +/- 2 part per thousand and were fed on a mixed culture of marine algae.

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Hardness:

No data

Test temperature:

21 degrees Celsius

pH:

8.0-8.2

Dissolved oxygen:

6.9-7.5 mg/L

Salinity:

33 +/- 2 parts per thousand

Nominal and measured concentrations:

Nominal: 10, 18, 32, 56, and 100 mg/L loading rate water-accommodated fraction.

Chemical analysis of test preparations at 0 hours showed measured concentrations to range from 7.0 to 36.8 mg/L. Analysis of the test preparations at 48 hours showed measured concentrations to range from 0.0929 to 1.44 mg/L. The decline in measured concentrations was in line with stability analysis conducted over a 48-hour period. However, given that the test material was prepared as a WAF and that toxicity cannot be attributed to a single component or a mixture of components but to the test material as a whole, the results were based on nominal loading rates.
 

Details on test conditions:

Range Finding test:
Acartia tonsa (19 -21 days) exposed to a series of nominal loading rates of 1.0, 10, and 100 mg/L. The test material was prepared as a water-accomodated Fraction (WAF). The results were used to determine the concentrations for the definitive test

Five Acartia tonsa were placed in each test and control vessel (50 ml flask containing 25 ml test media and covered) and maintained in a temperature controlled room at approximately 48 hours with photoperiod of 16 hours light and 8 hours darkness (20 minute day/night transition period) for a period of 48 hours. At 24 and 48 hous mortalities were recorded. Control group kept in the same conditions but no test material added.

Definitive test:
Doses of 10, 18, 32, 56 and 100 mg/L (WAF) were used.

Five Acartia tonsa (12 -14 days) were placed in each test vessel (50ml glass jars containing 25 ml of test medium) at random. Four replicates were prepared for each test concentration and control. The same exposure conditions were used as for the range finding study.

Test preperations were not renewed during the study. Water temperature was monitored and recorded daily throughout the study. Dissolved oxygen and pH were recorded at the start and the finish of the study.

Duration:

24 h

Dose descriptor:

LL50

Effect conc.:

ca. 40 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

mortality

Remarks on result:

other: 33-49 mg/L

Duration:

48 h

Dose descriptor:

LL50

Effect conc.:

ca. 25 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

mortality

Remarks on result:

other: 21-30 mg/L

Duration:

24 h

Dose descriptor:

NOELR

Effect conc.:

ca. 10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

ca. 10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

mortality

Details on results:

In the range-finding test, no mortality was observed at the 1.0 and 10.0 mg/L loading rate WAFs. However mortality was observed at the 100 mg/L loading rate WAF.

Following 48-hours of exposure in the defintive test, mortality was observed in 25, 65, 100, and 100% of the organisms at the 18, 32, 56, and 100 mg/L nominal loading rate test levels, respectively. No mortality was observed at the 10 mg/L test level or in the controls.

Results with reference substance (positive control):

the 24- and 48-hour percent mortalities for the reference substance (3,5-dichlorophenol) were 15% and 50% respecively

Reported statistics and error estimates:

The LL50 values and associated confidence limits were calculated by the maximum-likelihood probit method (Finney, 1971) using the ToxCalc computer software package (ToxCalc, 1999).

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity to the marine copepod Acartia tonsa has been assessed. The LL50 was determined to be 25 mg/L at 48 hours with a confidence limit (95%) of 21-30 mg/L/. The NOELR at 48 hours was 10 mg/L

Executive summary:

A study was performed to assess the acute toxicity of COASOL to Acartia tonsa. The method followed United Kingdom Proposal to ISO TC147/SC5/WG2 “Water Quality, Determination of Acute Lethal Toxicity to Marine Copepods (Copepoda, Crustacea).

 

Twenty Acartia tonsa (4 replicates of 5 organisms) were exposed to water-accommodated fractions (WAFs) of the test material over a range of nominal loading rates of 10, 18, 32, 56, and 100 mg/L for 48 hours at a temperature of 21°C to 22°C under static conditions. The number of mortalities was recorded after 24 and 48 hours.

 

Chemical analysis of test preparations at 0 hours showed measured concentrations to range from 7.0 to 36.8 mg/L. Analysis of the test preparations at 48 hours showed measured concentrations to range from 0.0929 to 1.44 mg/L. The decline in measured concentrations was in line with stability analysis conducted over a 48-hour period. However, given that the test material was prepared as a WAF and that toxicity cannot be attributed to a single component or a mixture of components but to the test material as a whole, the results were based on nominal loading rates.

 

The 48-hour LL50 was 25 mg/L, with 95% confidence limits of 21 – 30 mg/L. The NOELR was 10 mg/L.

Description of key information

COASOL 290 PLUS is a reaction mass of dibutyl glutarate and dibutyl adipate. The acute toxicity of COASOL 290 PLUS on Daphnia magna was assessed in an acute immobilisation test, over an exposure period of 48 hours in a semi-static test system. The test item was not fully soluble at all tested concentrations, hence a WAF method was used to produce a range of concentrations at nominal loading rates from 1.25 to 20.0 mg/L. Under the conditions of this Daphnia magna acute immobilisation test, the 48h EL50 value for COASOL 290 PLUS was 5.16 mg/L (95 % conf. limits: 4.77 – 5.58 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

5.16 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

25 mg/L

Additional information

One short-term aquatic (marine water) invertebrate toxicity study was available for COASOL and considered reliable for assessment of this endpoint. The study was conducted with the marine copepod (Acartia tonsa) and found to be of good quality and assigned a Klimisch score of one. Due to the limited water solubility of the test substance, the organisms were exposed to water-ammodated fractions resulting from solutions prepared at a nominal loading rates of 10, 18, 32, 56, and 100 mg/L. The study was conducted for 48-hours, under static conditions, following United Kingdom Proposal ISO TC147/SC5/WG2, and under GLPs. The study concluded the 48-hour LL50 value was 25 mg/L and considered the key parameter for this endpoint.