Reaction mass of dodecyl methacrylate and tridecyl methacrylate

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:

30th March 2018 to 15th 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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

60 mL of test samples from each replicate were withdrawn and mixed together for each group at 0 and 48 h. The samples were divided into two equal portions. One portion (120 mL) was sent for test concentration analysis and the second portion (120 mL) was stored at -20 ± 5 ºC until study completion.

Vehicle:

not specified

Details on test solutions:

A 21.4 mg quantity of test item was made up to 1000 mL with reconstituted water in glass bottles (Stock A) and kept under continuous (magnetic) stirring for approximate 24 h at room temperature. After stirring, test solutions were allowed to re-equilibrate for approximately 24 h. After phase separation, test solutions were collected from the lower portion using an “L” shaped glass tube without disturbing the phases. A volume of 900 mL was collected from the lower to middle portion of the bottle by pipette and used for treatment. Prior to adding test solution to vessels, test vessels were pre-conditioned with the respective test concentrations to saturate the surface of the respective vessel and to prevent loss of test concentration due to absorption into test vessels walls. Volumes of 200 mL from Stock A were taken in respective glass beakers (600 mL capacity) to obtain the loading rate of 21.4 mg/L.
A 30.0 mg quantity of test item was made up to 3000 mL with reconstituted water in glass bottles (Stock B) and kept under continuous (magnetic) stirring for approximately 24h at room temperature. After stirring, test solutions were allowed to re-equilibrate for approximate 24 h. After phase separation, test solutions were collected from the lower portion by “L” shaped glass tube without disturbing the phases. A volume of 2000 mL was collected from the lower to middle portion of the bottle by pipette and used for treatment. Prior to adding test solutions to vessels, test vessels were pre-conditioned with the respective test concentrations to saturate the surface of the respective vessel to prevent loss of test concentration due to absorption into test vessels walls. Volumes of 20, 44, 92 and 198 mL from Stock B were taken and diluted to 200 mL with reconstituted water in respective glass beakers of 600 mL capacity to obtain loading rates of 1.0, 2.2, 4.6 and 9.9 mg/L, respectively.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Not specified
- Age at study initiation (mean and range, SD): less than 24h (second instar)
- Weight at study initiation (mean and range, SD): Not specified
- Length at study initiation (length definition, mean, range and SD): Not specified
- Stage and instar at study initiation: second instar
- Source: Laboratory of Ecotoxicology, Jai Research Foundation (master culture sourse: MicroBio Test Inc., Kleimoer 15, 9030 Mariakerke (Gent), Belgium.
- Feeding during test : Not fed during test

ACCLIMATION
- Acclimation period: minimum period of 48h
- Type and amount of food: algae (Pseudokirchneriella subcapitata)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

184.8 CaCO3 mg/L water

Test temperature:

20.1 to 20.3°C

pH:

7.53 to 7.74

Dissolved oxygen:

8.02 to 8.80 mg/L

Salinity:

N/A

Conductivity:

no data

Nominal and measured concentrations:

nominal: 1.0, 2.2, 4.6, 9.9 and 21.4 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beaker
- Material, size, headspace, fill volume: 600 mL capacity, 100 mL fill volume
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Diluent water was aerated prior to use so that the dissolved oxygen concentration had reached saturation. Reconstituted water was prepared according to OECD 202.
- Intervals of water quality measurement: Temperature , pH and dissolved oxygen content of reconstituted water were recorded at 0 and 48h. Total hardness of reconstituted water was measured once during acclimatisation and the test period.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light; 8 hours dark cycle
- Light intensity: 1330 Lux (on day of acclimation)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): All daphnids were observed for immobility and abnormal behaviour or appearance at 0, 24 and 48 h of exposure. The 24 and 48h EL50, 48h EC50 and associated 95% confidence limits were calculated following the Probit analysis method using in-house developed, validated software.

RANGE-FINDING STUDY
- Test concentrations: 0 (Control), 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L.
- Results used to determine the conditions for the definitive study: The percent immobility observed were 0, 0, 0, 80, 100 and 100% at the loading rate of 0 (Control), 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L respectively.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EL50

Remarks:

WAF

Effect conc.:

5.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The percent immobilisation observed at 24h were 0, 0, 5, 40 and 65 at loading rates of 1.0, 2.2, 4.6, 9.9 and 21.4 mg/L respectively.
The percent immobilisation observed at 48h were 0, 5, 35, 80 and 100 at loading rates of 1.0, 2.2, 4.6, 9.9 and 21.4 mg/L respectively.
At 24h lethargy was observed in the 9.9mg/L group and the 21.4mg/L group. No behavioural symptom was observed in the 4.6mg/L group. No immobility or behavioural symptoms were observed in the 1.0, 2.2 or control groups. At 48h lethargy was observed in the 4.6mg/L group and 9.9mg/L group. All daphnids were found immobile at the test concentration of 21.4mg/L. No behavioural symptoms were observed in the group 2.2mg/L. No immobility or behavioural symptoms were observed in the group 1.0mg/L and control groups.
- Mortality of control: None
- Other adverse effects control: None
- Immobilisation of control: None

Results with reference substance (positive control):

- EC50 (48h): 0.43mg/L
- NOEC: 0.09mg/L
- LOEC: 0.20mg/L

Validity criteria fulfilled:

yes

Conclusions:

The 24 and 48 h EL50 (median effective loading concentration for immobilisation) of the test item were determined 14.5 and 5.9 mg/L (WAF), respectively.

Executive summary:

This study was performed in accordance with OECD TG 202 to assess the toxic effects on Daphnia magna caused by exposure under static conditions to Reaction mass of dodecyl methacrylate and tridecyl methacrylate.

Based on results of the preliminary range finding study, the main study was performed using water accommodated fraction (WAF) prepared at loading rates of 1.0, 2.2, 4.6, 9.9 and 21.4 mg/L along with a control. In the main study, a 48 h static toxicity test procedure was followed, comprising of six treatment groups along with a control. Each group consisted of four replicates with 5 daphnids per replicate.

The stability of the test item in test media was performed during method validation (JRF Study N° 228-2-13-19223). The test item in test media was stable up to 48 h (>80% of nominal concentration). Test media was analysed for active ingredient concentration and stability to assess test solutions at 0 and 48 h during the main study. The active ingredient concentration of the test item in test media was within an acceptable limit (>80% of nominal concentration).

The highest tested loading rate of the test item causing no immobilisation or the No Observed Effect Loading Rate (NOELR) was 1.0 mg/L. The lowest tested loading rate causing 100% immobilisation within the 48 h test period was 21.4 mg/L. The Lowest Observed Effect Loading Rate (LOELR) was 2.2 mg/L over the 48 h test item exposure period.

The highest tested concentration of test item causing no immobilisation or the No Observed Effect Concentration (NOEC) based on the geometric mean measured concentration was 0.04 mg a.i./L. The lowest tested concentration causing 100% immobilisation within the 48 h test period based on the geometric mean measured concentration was 1.08 mg a.i./L. The Lowest Observed Effect Concentration (LOEC) based on the geometric mean measured concentration was 0.09 mg a.i./L over the 48 h test item exposure period.

The 24 and 48 h EL50 (median effective loading concentration for immobilisation) of the test item were determined 14.5 and 5.9 mg/L (WAF), respectively. The 48 h EC50 (median effective concentration for immobilisation) of the test item based on the geometric mean measured concentration was determined as 0.30 mg a.i./L.

Description of key information

48 h EL50 = 5.9 mg/L (WAF) (Daphnia magna, OECD TG 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

5.9 mg/L

Additional information

This study was performed in accordance with OECD TG 202 to assess the toxic effects on Daphnia magna caused by exposure under static conditions to Reaction mass of dodecyl methacrylate and tridecyl methacrylate.

Based on results of the preliminary range finding study, the main study was performed using wateraccommodated fraction (WAF) prepared at loading rates of 1.0, 2.2, 4.6, 9.9 and 21.4 mg/L along with a control. In the main study, a 48 h static toxicity test procedure was followed, comprising of six treatment groups along with a control. Each group consisted of four replicates with 5 daphnids per replicate.

The stability of the test item in test media was performed during method validation (JRFStudy N° 228-2-13-19223). The test item in test media was stable up to 48 h (>80% of nominal concentration). Test media was analysed for active ingredient concentration and stability to assess test solutions at 0 and 48 h during the main study. The active ingredient concentration of the test item in test media was within an acceptable limit (>80% of nominal concentration).

The highest tested loading rate of the test item causing no immobilisation or the No Observed EffectLoading Rate (NOELR) was 1.0 mg/L. The lowest tested loading rate causing 100% immobilisation within the 48 h test period was 21.4 mg/L. The Lowest Observed Effect Loading Rate (LOELR) was 2.2 mg/L over the 48 h test item exposure period.

The highest tested concentration of test item causing no immobilisation or the No Observed EffectConcentration (NOEC) based on the geometric mean measured concentration was 0.04 mg a.i./L. Thelowest tested concentration causing 100% immobilisation within the 48 h test period based on the geometric mean measured concentration was 1.08 mg a.i./L. The Lowest Observed Effect Concentration (LOEC) based on the geometric mean measured concentration was 0.09 mg a.i./L over the 48 h test item exposure period.

The 24 and 48 h EL50 (median effective loading concentration for immobilisation) of the test item weredetermined 14.5 and 5.9 mg/L (WAF), respectively. The 48 h EC50 (median effective concentration for immobilisation) of the test item based on the geometric mean measured concentration was determined as 0.30 mg a.i./L.