Fatty acids, C9-13-neo-

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Not guideline study.

Justification for type of information:

See attached read across justification in Section 13.

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 305

Deviations:

yes

Remarks:

Not expected to impact study results.

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were taken for substance analysis on every day of uptake (14 days), and days 0, 3 and 9 of the 9 d depuration

Vehicle:

no

Details on test solutions:

The study design employed a stock mixing vessel, an intermediate mixing vessel (used to generate the desired nominal concentration), a dilution water vessel and a flow-through exposure tank. A 13L aspirator bottle was used for the stock mixing vessel. A 200 mg/L stock was prepared by adding the appropriate amount of test substance to dilution water in the aspirator bottle. The solution was mixed with a Teflon® coated stirbar (added to the vessel prior to the addition of the test substance) on magnetic stirplate prior to use. Mixing intensity was sufficient enough to form a vortex, but not form an emulsion. The mixing vessel was closed with a foil covered stopper with glass tubing to allow air into the bottle during use. For the initial start-up of the system, samples were taken from the stock solution and analyzed prior to use to determine the dilution required to achieve the desired 2 mg/L exposure concentration. Once the intermediate vessel and exposure tank were filled with solution and verified at ~2 mg/L, the flow-through system was started and fish were added to the tanks. For the remainder of the uptake phase, the 200 mg/L stock solution mixed for 48 hours (± 4 hours before being used in the flow-through system). The stock solution was pumped into the intermediate vessel at a rate of ~2 mL/minute through the outlet at the bottom of the vessel. Dilution water will be pumped into the intermediate vessel at ~98 mL/minute from a 20L size aspirator bottle. The 20L size aspirator bottle was replenished at approximately 100 mL/minute from the laboratory reconstituted water system, this bottle contained approximately 10-15L and acted as a buffer tank to supply diluent. This process resulted in a ~2 mg/L solution which was then pumped into the flow-through exposure tank with a peristaltic pump and silicone tubing at ~100 mL/minute. The exposure tank contained a standpipe, limiting the volume to approximately 31L, at the prescribed flow rate approximately 4.5 water changes will occur per day. An equivalent system will be used for the Control treatment, except that no test substance was added to the “stock” mixing vessel.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

The stock population was acclimated in dilution water for at least two weeks at test temperature. They were fed 1-2% of body weight per day. Any remaining fish from the stock population were maintained for a reasonable time, so that they may be used for method development, training purposes, etc., following that they will be euthanized using a tricaine methane sulphonate (MS 222) solution, prepared in laboratory dilution water. An MS 222 solution is the preferred euthanasia method for fish from an animal care and use perspective. Fish were held under static conditions using biological and mechanical filtration and are fed daily with Finfish Starter.

Fish were sequentially added into the test chambers until each chamber contained 40 fish.

To ensure that quality organisms were used for the study, fish were selected from a pool of organisms larger than that needed for the study. The study director's designee determined organism suitability.

Test type:

flow-through

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

10 d

Post exposure observation period:

9 d (depuration phase of BCF study)

Hardness:

Average hardness of 12 batches of dilution water was 91 mg CaCO3/L

Test temperature:

14.3 +/- 0.7 C

pH:

Treatment group: 8.2 +/- 0.2
Control group: 8.1 +/- 0.2

Dissolved oxygen:

Treatment: 9.9 +/- 0.6 mg/L
Control: 9.8 +/- 0.7 mg/L

Salinity:

Average TOC of 12 batches of dilution water was 0.06 ppm

Nominal and measured concentrations:

2.0 mg/L (nominal); 2.2 mg/L (measured)

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

> 2.22 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

No effects were seen on growth from 14 d exposure of rainbow trout to 2.22 mg/L neodecanoic acid.

Validity criteria fulfilled:

yes

Conclusions:

In an aqueous BCF study with 14 d exposure of rainbow trout juveniles to 2.22 mg/L neodecanoic acid, no effects on growth and no mortality were observed.

Reference 2

Endpoint:

long-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The value was calculated based on chemical structure as modeled by EPIWIN. This robust summary has a reliability rating of 2 because the data are calculated and not measured.

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Principles of method if other than guideline:

QSAR based on ECOWIN v1.00 (in EPISuite v4.00)

GLP compliance:

no

Analytical monitoring:

not required

Vehicle:

no

Details on test solutions:

na

Test organisms (species):

other: freshwater fish

Test type:

other: computer model

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 d

Hardness:

na

Test temperature:

na

pH:

na

Dissolved oxygen:

na

Salinity:

freshwater

Nominal and measured concentrations:

na

Details on test conditions:

na

Reference substance (positive control):

no

Duration:

30 d

Dose descriptor:

other: ChV

Effect conc.:

1.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: calculated

Conclusions:

A chronic aquatic toxicity value was calculated using the ECOWIN computer model. The calculated chronic value for neodecanoic acid includes a 30-day freshwater fish value of 1.6 mg/l.

Executive summary:

The calculated chronic value for neodecanoic acid includes a 30-day freshwater fish value of 1.6 mg/l.

Description of key information

A 30 d Chronic Value (ChV) of 1.6 mg/L was calculated using the ECOSAR module of EPISuite v4.00.
No effects were seen on growth from 14 d exposure of Oncorrhynchus mykis to 2.22 mg/L neodecanoic acid.

Additional information

A 30 d fish Chronic Value (ChV) of 1.6 mg/L was calculated using the ECOSAR module of EPISuite v4.00.

No effects were seen on growth from 14 d exposure of Oncorrhynchus mykis to 2.22 mg/L neodecanoic acid.