3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 04 – 08, 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study, tested with the source substance branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3). According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2012)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
Due to the high biodegradation potential and the difficult dissolving properties of branched-nonyl 3,5,5 trimethylhexanoate, the appropriate method of dosing the test item was by preparation of a Water Accommodated Fraction (WAF).
One WAF per test concentration was prepared according to the OECD guidance No. 23.
The test item was weighed and immediately transferred to dilution water of appropriate volume. The solution was prepared in a glass bottle which was equipped with a drain port.
The contents of the vessels were stirred at 100 rpm (digital display) for 24 h at room temperature (21 ± 1°C). After stirring, the contents of the vessels were left to settle for a further 24 h. The saturated aqueous phase was then drained via the drain port. The first 100 mL were discarded. The mid part of the water body was used for filling the test vessels.
The test medium was used immediately and not kept longer than 1 - 2 hours. The remaining eluate was discarded.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebrafish
- Strain: Danio rerio (Teleostei, Cyprinidae)
- Source: test facility bred
- Weght: 0.13 g
- Length at study initiation (length definition, mean, range and SD): mean 2.4 cm
- Feeding during test: no feeding of the fish occurred during the test as well as 24 h before test start.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

1.0 mmol/L

Test temperature:

Mean: 22.9 °C

pH:

Mean: 8.4

Dissolved oxygen:

Mean: 95 mg/L

Nominal and measured concentrations:

A limit test with one nominal loading of 100 mg test item/L

Details on test conditions:

TEST SYSTEM
- Test vessel: the test vessels were full glass aquaria of 12 L for keeping up to 10 litres of test solution
- Type: the test vessels were slightly aerated via a glass capillary
- Renewal rate of test solution: once, after 48 h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: purified drinking water
- Total organic carbon: 0.65 mg/L
- Metals: copper < 6.75 µg/L, iron < 7.35 µg/L, manganese < 2.99 µg/L, zinc < 1.57 µg/L.
- Chlorine: <0.02 mg/L
- Alkalinity: 1.6 mmol/L
- Ca/Mg ratio: 0.7/0.3
- Conductivity: 216.8 µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: monthly

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 12/12 hours


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality and clinical signs (sub-lethal and abnormal behavior) were recorded at 3 h, 24 h, 48 h, 72 h and 96 h after fish exposure.

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: limit test
- Range finding study: yes
- Test concentrations: 100 mg/L
- Results used to determine the conditions for the definitive study: range finding test at nominal loadings: 100 mg/L, 10 mg/L and 1.0 mg/L. No mortality, clinical signs or any distress were observed throughout the range finding test.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: no abnormalities
- Observations on body length and weight: at the beginning of the study
- Other biological observations: no clinical signs or sublethal effects (e.g. loss of equilibrium, change in swimming behaviour, etc.)
- Mortality of control: no mortality in control
- Other adverse effects control: no adverse effects
- Abnormal responses: no
- Effect concentrations exceeding solubility of substance in test medium: the evaluation of the effects was based on nominal loading concentration for the test solution preparation.

Sublethal observations / clinical signs:

Neither clinical signs nor mortality could be observed throughout the study (Table 1), (Table 2).

Table 1: Clinical signs during the test period of 96 h (number of fish per treatment n=7)

Nominal loading test item [mg/L]	Test duration
	3 h	24 h	48 h aged	48 h fresh	72 h	96 h
Control	nd.	nd.	nd.	nd.	nd.	nd.
100	nd.	nd.	nd.	nd.	nd.	nd.

nd.: no symptoms detected

Table 2: Cumulative mortality during the test period of 96 h (number of fish per treatment n=7)

Nominal loading test item [mg/L]	Test duration
	3 h	24 h	48 h aged	48 h fresh	72 h	96 h
Control	0	0	0	0	0	0
100	0	0	0	0	0	0

 

Validity criteria fulfilled:

yes

Conclusions:

Based on the results of this study, the LL50 of branched-nonyl 3,5,5 trimethylhexanoate was determined to be > 100 mg test item/L. The NOEL based on the visual observation is reported as >= 100 mg/L .

Executive summary:

In the 96 h acute toxicity test, conducted according to the OECD guideline 203, zebrafish (Danio rerio) were exposed to a Water Accommodated Fraction (WAF) of the test item branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3) at nominal loading concentration of 100 mg/L under semi-static conditions. Neither clinical signs nor mortality were observed throughout the study. Seven fish were used for treatment and in the control.

Based on the results of this study, the LL50 of branched-nonyl 3,5,5 trimethylhexanoate was determined to be > 100 mg test item/L. The NOEL based on the visual observation is reported as >= 100 mg/L (NOEL >= 100 mg/L).

 

This toxicity study is classified as acceptable and satisfies the guideline requirement for “Fish, Acute Toxicity Test”.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

See the document "Rationale & justification for the Analogue read across approach used in the registration dossier of 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate CAS 59219-71-5" in section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Validity criteria fulfilled:

yes

Executive summary:

Since no studies investigating the acute toxicity of 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) towards fish are available, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read across to the structurally related analogue substance branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3) was conducted. This read across is justified, as both source and target substances are characterized by equal fatty acid moieties ( 3,5,5 trimethylhexanoic acid) and/or similar alcohol moieties (C9 iso alcohol with varying branching options). The read-across is justified in more detail within the analogue justification in IUCLID Section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was used for the assessment.

Neither clinical signs nor mortality were observed in the OECD 203 test, where Danio rerio have been exposed under semi-static conditions to Water Accommodated Fractions (WAF) at the nominal loading rate of 100 mg/L. Based on the results of this study performed on the source substance, the LL50 of  the target substance 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) was determined to be > 100 mg test item/L. The NOELR based on the visual observation is reported as ≥ 100 mg/L (NOELR ≥ 100 mg/L).

It can be concluded that 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) does not pose an acute hazard to fish.

Description of key information

No effects up to the limit of water solubility (1.5-4.4 µg/L at 20 °C; OECD 203), read across.

Additional information

Since no studies investigating the acute toxicity of 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) towards fish are available, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read across to the structurally related analogue substance branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3) was conducted. This read across is justified, as both source and target substances are characterized by equal fatty acid moieties ( 3,5,5 trimethylhexanoic acid) and/or similar alcohol moieties (C9 iso alcohol with varying branching options). The read-across is justified in more detail within the analogue justification in IUCLID Section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was used for the assessment.

The study (IME, 2013) with the branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3) was conducted according to the OECD guideline 203, zebrafish (Danio rerio). In the 96 h acute toxicity test, fish were exposed to a Water Accommodated Fraction (WAF) of the test item branched-nonyl 3,5,5 trimethylhexanoate at a nominal loading rate of 100 mg/L under semi-static conditions. Neither clinical signs nor mortality were observed throughout the study. Seven fish were used for treatment and in the control. Based on the results of this study, the LL50 of branched-nonyl 3,5,5 trimethylhexanoate was determined to be > 100 mg test item/L. The NOELR based on the visual observation is reported as ≥ 100 mg/L (NOELR ≥ 100 mg/L).

Based on the results from the structurally related source substance (branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3)) it can be concluded that 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) does not pose an acute hazard to fish.