Isooctadecyl pivalate

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:

11 Jul 2015 - 14 Mar 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in accordance with current guidelines and GLP compliance

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

not required

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: the test loading was prepared by applying the Water Accommodated Fraction (WAF) approach according to the OECD
guidance
documents No. 23
- Eluate: 100 mg test item were transferred into a 2 L sterile glass flask with a drain port at the bottom via a Teflon weighing boat.
The flask was brought to a volume of about 1 L with copper free tap water to obtain the required nominal loading of 100 mg/L. The test
media
was stirred slowly to prevent bubble, foam or emulsion formation using a star shape magnetic stirring bar for at least 48 h at room
temperature
(~20°C).
After stirring the saturated lower aqueous phase was taken out of the drain port. The first fraction 0 - 200 mL was discarded. Approx.
600 mL were centrifuged at 15,000 G for 15 minutes. Polypropylene tubes were used for centrifugation. After this step, they were
lancinated with a solid syringe - connected with a flexible tube - to purge the lower aqueous layer into a sample vessel. Eluates were
checked for irregularities such as foam formation prior to exposure and filling of the test flasks (50 - 100 mL volume) for toxicity testing.
- Controls: Dilution water only, treated like described above.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): at start of the test: none

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: German Federal Environment Agency, Institut für Wasser-, Boden- und Lufthygiene.
- Source: Specimens used in the test were bred in the laboratory of the Fraunhofer IME.
- Age of parental stock: at least 3 weeks old
- Feeding during test: Yes
- Food type: Desmodesmus subspicatus
- Amount: 0.2 mg C/(Daphnia * day)
- Frequency: 3 times a week

ACCLIMATION
- Acclimation period: 1 week
- Acclimation conditions (same as test or not): Same
- Type and amount of food: algal suspension (Desmodesmus subspicatus) and LiquizellR (HOBBY)
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): No mortality observed

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Newborn Daphnia were separated by sieving, the first generation was discarded. Individuals applied in the test are transferred with a bore Pasteur pipette a few hours after sieving to ensure applying only healthy specimens.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

1.0 - 1.1 mmol/L

Test temperature:

19.6 - 20.2 °C

pH:

7.7 – 9.0 at all treatment levels

Dissolved oxygen:

8.0 mg/L – 11.0 mg/L

Nominal and measured concentrations:

100 mg/L loading

Details on test conditions:

TEST SYSTEM
- Test vessel: Beaker
- Type (delete if not applicable): Covered with glass panes to prevent from evaporation as much as possible, but also permit gaseous exchange between the medium and the atmosphere and access of light.
- Material, size, headspace, fill volume: Glass, 70 mL, 20 mL, 50 mL
- Aeration: Not active
- Renewal rate of test solution (frequency): 3 times per week
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Copper free tap water
- Total organic carbon: NPOC 0.59 – 0.76 mg/L
- Particulate matter: -
- Metals: Cd <0.865 µg/L, Cr <0.841µg/L, Cu <5.82µg/L, Fe <1.58µg/L, Mn <1.08µg/L, Ni <1.24µg/L, Pb <1.74µg/L, Zn ≤2.13µg/L
- Pesticides: -
- Chlorine: <0.02 – 0.02 mg/L
- Alkalinity: 1.8 - 2.0 mmol/L
- Conductivity: 206 - 242 µS/cm
- Intervals of water quality measurement: Monthly

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16/8 (L/D)
- Light intensity: 698 – 871 lx (corresponding to 9.3 – 11.6 µE/(m² *s))

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobilization of adults, number of juveniles, daily until day 11. Subsequently at every media renewal.

Reference substance (positive control):

not required

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

loading

Basis for effect:

other: Immobilisation and reproduction

Duration:

21 d

Dose descriptor:

LOELR

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

loading

Basis for effect:

other: immobilisation and reproduction

Details on results:

CONTROL ASSAYS
- Mortality of parent animals: 0 %
- No. of offspring produced per female: 89.8 +/- 13.8
- Body length of parent animals: 0.51 +/- 0.03 cm
- Type and number of morphological abnormalities: None
- Type and number of behavioural abnormalities: None
- Number of males and females (parental): No males
- Age at first brood release: 7.7 +/- 0.42
- Other biological observations: Intrinsic rate of increase 0.34 +/- 0.02 Ind./day

Reported statistics and error estimates:

Cumulative Offspring, Age of first reproduction, Intrinsic rate of increase, Length of adults at test end: Normal distribution (Shapiro-Wilk´s Test) and variance homogeneity (Levene’s test) requirements were fulfilled. Thus, a parametric multiple test was advisable. The Student-t test for Homogenous Variances was chosen.
Immobilisation of adults: Fisher`s Exact Binomial Test.
For no endpoint treatment is significantly different from control (p < 0.05).

Table1:  Survival, growth and reproduction data.

SD = standard deviation. For raw data see Annex 1. Number ofD. magnaper concentration: n = 10. TI = test item.

Concentration	Parental survival	Growth (length on day 21)	Age at first brood	Cumulative offspring per female	Intrinsic rate of increase
(mgTI./L)	(%)	Mean±SD (cm)	Mean±SD (days)	Mean±SD (Ind.)	Mean±SD (Ind./day)
Control	100	0.51±0.03	7.7±0.42	89.8±13.8	0.34±0.02
100	90	0.53±0.05	7.9±1.26	95.4±14.2	0.34±0.02

Table2:               Effect summary table

Concentration	Parental survival	Growth (length on day 21)	Age at first brood	Cumulative offspring per female	Intrinsic rate of increase
NOEL	≥100 mg TI/L	≥100 mg TI/L	≥100 mg TI/L	≥100 mg TI/L	≥100 mg TI/L
LOEL	>100 mg TI/L	>100 mg TI/L	>100 mg TI/L	>100 mg TI/L	>100 mg TI/L

Validity criteria fulfilled:

yes

Conclusions:

Isooctadecyl pivalate has no chronic adverse effect on adult Daphnia magna under the chosen test conditions. The mean cumulative offspring of survivors, the age to first brood, intrinsic rate, and adult growth (body length) show no significant difference between control and the test concentration up to and including a nominal loading of 100 mg/L. The NOELR is ≥ 100 mg TI/L and the LOELR is > 100 mg TI/L nominal loading in the limit test.

Executive summary:

At the Fraunhofer Institute for Molecular Biology and Applied Ecology the influence of isooctadecyl pivalate on the reproduction of aquatic invertebrates, represented byDaphnia magna, was investigated. A 21 day semi-static exposure to isooctadecyl pivalate at a nominal loading of 100 mg/L with renewal of the test solutions three times a week was conducted according to the OECD guideline 211 (limit test). Untreated control replicates were run in parallel. Each treatment group consisted of 10 replicates with one daphnid each (individual exposure). Effects on growth (adult length at test termination) and reproductive performance were investigated.

Test item loading of 100 mg/L did not affect the mean cumulative offspring of survivors, the age to first brood, intrinsic rate, and adult growth (body length). The NOELR is ≥ 100 mg TI/L and the LOELR is > 100 mg TI/L in the limit test.

Description of key information

No effects up to the water solubility limit (1.0 - 27 µg/L, mean: 11.7 µg/L; OECD 201)

Additional information

The influence of Isooctadecyl pivalate on the reproduction of aquatic invertebrates, represented by Daphnia magna, was investigated. A 21 day semi-static exposure at a nominal loading of 100 mg/L with renewal of the test solutions three times a week was conducted according to the OECD guideline 211 (limit test). Untreated control replicates were run in parallel. Each treatment group consisted of 10 replicates with one daphnid each (individual exposure). Effects on growth (adult length at test termination) and reproductive performance were investigated. Test item loading of 100 mg/L did not affect the mean cumulative offspring of survivors, the age to first brood, intrinsic rate, and adult growth (body length). The NOELR (21 d) is ≥ 100 mg/L and the LOELR is > 100 mg/L in the limit test.