Neodecanoic acid, zirconium salt

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:

09-16 Mar 2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Ceriodaphnia dubia, Survival and Reproduction Test Method 1002.0 in Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater

Version / remarks:

4th Edition. EPA-821-R-02-013

Deviations:

no

GLP compliance:

no

Remarks:

GLP complaint laboratory; QA review was limited to raw data and final report.

Analytical monitoring:

yes

Details on sampling:

Analytical samples were collected in 2 x 40 mL VOA vials and refrigerated prior to analysis if not analyzed the same day. Two replicates were collected for each treatment. Two replicates were analyzed by Headspace GC-FID on Days 0 (fresh), 1 (fresh and old), 2 (fresh and old), 3 (fresh and old) and 4 (fresh and old). For Day 1 fresh, 6 fresh and Day 7 old samples, 1 sample was analyzed by Headspace GC-FID while the other was analyzed using BE-SPME.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
The test solutions were prepared by adding the appropriate amount of test substance to dilution water in a glass aspirator bottle and stirring on a magnetic stirplate for approximately 24 hours. Clear test material was visible on the surface at the time of mixing and when mixing was stopped. The mixture was allowed to settle for 1 hour (± 30 minutes) before removing the aqueous portion for testing. Fresh treatment and control solutions were prepared daily. Due to the nature of the test substance, pH adjustment of the treatment solutions was necessary prior to the use of the test solutions in order to bring the pH within ± 0.2 of the control.
A control treatment consisting of dilution water (moderately hard reconstituted water) with no test substance was also prepared.

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

C. dubia were cultured at the testing facility under conditions similar to the test. The neonates (less than 24h old) used for this study were from adults that were 11 days old.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Test temperature:

The temperature in the test area ranged from 27.4 to 28.3 C.
Discrete measurements at the time of water quality analysis ranged from 21.6 to 25.5, and do not reflect temperature in the expsoure area.

pH:

Group Nominal Measured C pH†
[-] mg/L mg/L (adjusted)
1 0 (Control) <0.05 7.79 - 8.46
2 1.0 1.6 7.72 - 8.22
3 3.0 3.4 7.63 – 8.19
4 10 9.8 7.62 – 8.20
5 30 28 7.22 – 8.30
6 100 84 7.94 – 8.14
†New solution pH was adjusted using NaOH. Minor adjustment (+0.1 to +0.3) was needed one to two days for the 1.0 and 3.0 mg/L treatments. The pH of remaining treatments 10mg/L (+0.1 to +0.4), 30 mg/L (+0.6 to +1.0), 100 mg/L (+1.0 to +1.5) were adjusted daily.

Dissolved oxygen:

Group Nominal Measured Dissolved Oxygen
[-] mg/L mg/L mg/L
1 0 (Control) <0.05 8.17 – 10.13
2 1.0 1.6 7.94 – 9.92
3 3.0 3.4 7.92 – 10.69
4 10 9.8 7.87 – 10.25
5 30 28 7.95 – 10.73
6 100 84 8.13 – 10.44

Nominal and measured concentrations:

Mean measured concentrations for the study were 1.6, 3.4, 9.8, 28 and 84 mg/L respectively, for the 1.0, 3.0, 10, 30 and 100 mg/L nominal concentrations.

Details on test conditions:

TEST SYSTEM:
Ten replicates were established for each of the test substance treatments and the control using one test organism per replicate. Test chambers were 30 mL PTFE (polytetrafluoroethylene) plastic beakers filled with 15 mL of test solution and feed; 50 µL of YCT (yeast-cereal leaves-trout chow mixture) and 100 µL of Pseudokirchneriella subcapitata algae

TEST MEDIUM / WATER PARAMETERS:
Reconstituted water (American Public Health Association, American Water Works Association and Water Environment Federation. 2005. Method 8010E Table 8010-I) was prepared from UV-sterilized, deionized well water and salts (NaHCO3, CaSO4, MgSO4, and KCl), and was aerated prior to use. The deionized water is monitored annually for priority pollutants, un-ionized ammonia, total suspended solids, and for bacterial properties.
Temperature, pH, and dissolved oxygen were measured at the beginning and end of each 24 hour exposure.

OTHER TEST CONDITIONS:
Temperature and lighting were continuously monitored via computer in the test area. The temperature in the environmental chamber ranged from 27.4 to 28.3 ºC. Photoperiod 16 h light : 8 h dark, provided with cool white fluorescent bulbs.

EFFECT PARAMETERS MEASURED:
Observations for immobilization were performed and recorded at 24 ± 1 h intervals after test initiation. The adults were transferred via pipette to chambers containing fresh test solution daily. Neonate presence and counts from each adult was performed following the adult transfer on a daily basis.

Duration:

7 d

Dose descriptor:

LOEC

Effect conc.:

9.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

7 d

Dose descriptor:

NOEC

Effect conc.:

3.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

This study was considered acceptable since there was no mortality of control daphnids by the end of the study and 100% of control daphnids produced three broods. The mean number of live offspring produced per adult in the control group surviving at the end of study was 17.1 neonates.

No abnormal behavior or appearance of the adults was observed in the control or treatment groups. No observations of aborted eggs were noted in the control or treatment groups throughout the entire exposure. No immobilization of adults was observed in any treatment. Mean number of neonates produced for the control and treatment groups are provided in Table below.

Reported statistics and error estimates:

The NOEC and LOEC values were calculated using TOXSTAT (WEST Inc & Gulley 1994) with a student t-test with Bonferroni adjustment (Bland, 1995).

Validity criteria fulfilled:

yes

Remarks:

(<20% mortality, >= 60% produce 3 broods, >= 15 neonates per adult)

Executive summary:

In a 3 -brood survival and reproduction test, the freshwater cladoceran, Ceriodaphnia dubia were exposed to mean measured concentrations of neo-decanoic acid of 0 (control), 1.6, 3.4, 9.8, 28 and 84 mg/L under semi-static conditions. The NOEC and LOEC values, based on reproduction, were 3.4 and 9.8 mg/L, respectively. This study was considered acceptable and satisfies all guideline validity requirements.

Description of key information

A 7-day chronic NOEC value of 3.4 mg/L for Ceriodaphnia dubia (US EPA Test Method 1002.0 - Survival & Reproduction) exposed to neodecanoic acid.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

3.4 mg/L

Additional information

Experimental long-term toxicity data for the registered substance are adequate for the purpose of classification and labelling and/or risk assessment. Supporting information is provided by chronic aquatic toxicity values calculated using the neutral organics-acid structure-activity relationship in the ECOSAR computer program (Nabholz and Mayo-Bean, 2009) of EPISuite; the results of which are consistent with the measured test data. The experimental NOEC of 3.4 mg/L is also consistent with data for a similar material, Neoheptanoic acid which produced a 21-Day NOEC of 4.8 mg/L for Daphnia magna.