Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methacrylate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-09-23 to 2010-05-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 211, GLP, analytical monitoring.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

(2008)

Deviations:

no

Principles of method if other than guideline:

A semi-static test design (with a daily water renewal) in closed bott!es without headspace was chosen because of the vo!atility of the test item.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: STRAUS (Clone 5)
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), Germany
- Age at study initiation (mean and range, SD): 2 to 24 hours
- Length at study initiation (length definition, mean, range and SD): no data
- Weight at study initiation (mean and range, SD): mean weight: no data
- Method of breeding: Laboratory bred
- Food type: unicellular green algae e.g. Pseudokirchneriella subcapitata, Desmodesmus subspicatus and Cholorella vulgaris
- Amount: corresponding to 0.2 mg C per daphnia and day
- Frequency: daily

ACCLIMATION
- Acclimation period: test organism is bred at test facility
- Health during acclimation (any mortality observed): no data

Test type:

semi-static

Limit test:

no

Total exposure duration:

21 d

Hardness:

Total hardness: test concentrations: 144 to 164 mg/L as CaCO3
control: 157 to 174 mg/L as CaCO3

Test temperature:

18 - 22 °C ± 2 °C constant

pH:

test concentrations: 7.23 to 7.82
control: 7.34 to 7.96

Dissolved oxygen:

test concentrations: 7.56 to 8.52 mg/L
control: 6.87 to 8.78 mg/L

Nominal and measured concentrations:

1:1 (saturated test item solution), 1:2, 1:4, 1:8, 1:16 prepared with dilution water
corresponding to geometric mean measured concentrations: 2.56, 0.909, 0.428, 0.233, 0.111 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: sealed glass flasks
- Type (delete if not applicable): closed because of volatile test substance
- Material, size, headspace, fill volume: 4.5 (ID) x 9.5 (H) cm, ca. 130 mL; filled up with the test solutions having nearly no headspace to reduce losses of the test item
- Aeration: no aeration
- Renewal rate of test solution (frequency/flow rate): daily
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4, according to Elendt (1990), modified to a total hardness of 160 to 180 mg CaCO3/L
- Total organic carbon: 160 to 180 mg CaCO3/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: Dissolved oxygen concentration, pH-values, total hardness and water temperature were measured once
every 7 days, in fresh and old media, in one replicate of the control and the saturated solution or the next appropriate dilution level.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hr light / 8 hr dark cycle
- Light intensity: max. 20 µE*mE-2*sE-1

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

Mortality of parental daphnids
The number of parental daphnids which were immobilized or dying during the test and day of death were observed and recorded once a day at
least at the same time as the offspring was counted. Dead specimen were removed.

Neonates
First appearance of juveniles was checked daily. The number of neonates (alive and dead progeny) was counted and dates of release were recordedonce a day from the first day of production of neonates unti! the end of the test. The neonates (alive and dead) were removed after counting and
before addition of algae to prevent from consuming food intended for the adults. The number of aborted eggs or dead offspring and dates of
observation were recorded.

Condition of parental daphnids
Abnormalities (e.g. swimming behaviour, number of male and winter eggs) were observed and recorded at each day of observation.

Total length and dry body weight of parental daphnids
At the end of the test total length of each daphnid and the mean dry body weight of the daphnids alive in all dilution levels and control were
determined.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.658 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: calculated by sigmoidal dose-response regression; EC50: 0.558 - 0.775 mg/L (Confidence interval, p=95 %)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.233 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.428 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.851 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

adult daphnids

Remarks on result:

other: calculated by sigmoidal dose-response regression; EC50: 0.428 - 2.56 mg/L (Confidence interval, p=95 %)

Details on results:

- Mortality of parent animals: The test item induced significant adult mortality at the concentration levels 0.909 mg/L (90 %) and 2.56 mg/L (100 %)
after 21 days. At the other concentration levels and at the control no mortality of parent animals was observed.
- Body length and weight of parent animals: The mean values of the body length of the surviving parental daphnids at the test groups were in the
range of 4.75 to 5.30 mm per daphnid were comparable to the control group with 5.15 mm per daphnid. The mean dry body weight was determined to be in the range of 0.77 to 1.00 mg per daphnid at the test groups and 0.77 mg per daphnid at the control, respectively.
- Time to first brood release or time to hatch: The first brood was released till day 10 by all parent animals of the control and the concentration levels 0.111 to 0.428 mg/L. The parental daphnid of the concentration level 0.909 mg/L released its first brood on day 15. Release of the first brood after day 10 is regarded to be too late and biologically significant.

Results with reference substance (positive control):

- Results with reference substance valid?: yes
- Relevant effect levels: EC50: 1.29 mg/L (CL: 1.15 - 1.46 mg/L), immobilization after 24 hr.

Reported statistics and error estimates:

One Way Analysis of Variance on Ranks, Dunnett's method, p=0.05

Validity criteria fulfilled:

yes

Remarks:

To prove the validity of the test system and test conditions, an acute immobilization test according to DIN 38412 L 11 is carried out with potassium dichromate as reference item once per month.

Conclusions:

In this valid guideline study (OECD 211, semi-static conditions), the 21 day reproductive toxicity to daphnids was determined to be
EC50 for Daphnia magna (STRAUS Clone 5) was 0.658 (0.558 - 0.775) mg/L, NOEC: 0.233 mg/L and LOEC: 0.428 mg/L for Isobornyl methacrylate.
All effect values given are based on the geometric mean measured test concentrations of Isobornyl methacrylate.

Executive summary:

The 21-day-chronic toxicity of Isobornyl methacrylate to Daphnia magna STRAUS (Clone 5) was studied under semi-static (daily renewal) conditions. Daphnids were exposed to control, and test chemical at measured concentrations of 0.111, 0.233, 0.428, 0.909, and 2.56 mg a.i./L. The 21 day EC₅₀based on reproductive effects was 0.658 (CI 95%: 0.558 - 0.775) mg a.i./L.  The 21-day NOEC based on reproductive effects was 0.233 mg a.i./L (the highest test concentration with no significant reduction of the reproductive output). The reduction of the reproductive output at the concentration levels of 0.111 and 0.233 mg/L was not statistically significant in comparison to the control group.

At a concentration of 0.428 and 0.909 mg/L the reproductive output was reduced.

The concentration level of 2.56 mg/L produced no offspring due to mortality of all parental daphnids before day 5 of the exposure phase. Therefore no intrinsic rate of natural increase (IR) was calculated. The IR was statistically significant different at the tested concentration levels of 0.428 and 0.909 mg/L when compared to the control. At the other concentration levels 0.111 and 0.233 mg/L no statistically significant difference in comparison to the control was determined.

At the test groups the coefficient of variation came to a maximum of 16 % at 0.428 mg/L and were comparable to the control (14 %).

The most sensitive end points were the reduction of the reproductive output and the intrinsic rates of natural increase (IR) .

 

The first brood was released till day 10 by all parent animals of the control and the concentration levels 0.111 to 0.428 mg/L. The surviving parental daphnid of the concentration level 0.909 mg/L released its first brood on day 15. Release of the first brood

after day 10 is regarded to be too late and biologically significant.

Four to five broods were observed at the concentration levels 0.111 to 0.428 mg/L and control during the course of the study. Three broods were observed by the surviving parental daphnid of the test concentration 0.909 mg/L.

No stillborn juveniles and aborted eggs were produced by the control group. Related to the total number of produced juveniles (dead + alive) the percentage of dead juveniles was biologically significant at the tested concentration level 0.909 mg/L (39 %).

The test item induced significant adult mortality at the concentration levels 0.909 mg/L (90 %) and 2.56 mg/L (100 %) after 21 days. At the other concentration levels and at the control no mortality of parent animals was observed. The EC50 for adult mortality after 21

days was calculated by sigmoidal dose-response regression to be 0.851 mg/L (CI: 0.428 - 2.56 mg/L).

The mean values of the body length of the surviving parental daphnids at the test groups in the range of 4.75 to 5.30 mm per daphnid were comparable to the control group with 5.15 mm per daphnid. The mean dry body weight was determined to be in the range of 0.77 to 1.00 mg per daphnid at the test groups and 0.77 mg per daphnid at the control, respectively.

This study is classified as acceptable and satisfies the guideline requirements for a chronic toxicity study with freshwater invertebrates.

 

Results Synopsis

 

Test Organism Age: Daphnia magna, 2 hr to 24 hr old

Test Type: semi-static, daily renewal, closed system

 

NOEC(reproduction): 0.233 mg a.i./L

LOEC(reproduction): 0.428 mg a.i./L                     Endpoint(s) Effected: reproductive output, IR 

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

One reliable long term study for Isobornyl methacrylate on aquatic invertebrates

is available acc. OECD 211. NOEC (21d) on Daphnia magna was determined to be 0.233 mg/l.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.233 mg/L