Potassium 3,5,5-trimethylhexanoate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Name: Potassium 3,5,5-trimethylhexanoate
CAS No.: 93918-10-6
Batch No.: PURS151015
Purity: 99.4%
Physical State: solid
Colour: white
Molecular Weight: 196.33 g/mol
Storage Conditions: room temperature
Re-certification Date: 14 October 2016

Analytical monitoring:

yes

Details on sampling:

TOC analysis
A static test design was applied with an accompanying TOC-analysis. The swimming capability of the daphnids was assessed after 24 h and 48 h exposure. Samples of 5 mL were taken from each additional vessel for TOC-analysis (without test organisms in order to not disturb the TOC-analysis) of the test item treatment and NC at 0 h, 24 h and 48 h. Of these 4 samples per treatment and time, 2 were measured directly after sampling using a TOC-analyser and 2 samples were stored as retain samples in the freezer at ≤ -18 °C until finalization of the study.

Vehicle:

yes

Details on test solutions:

The test was performed with M4 medium according to OECD 202 (2004).

Test organisms (species):

Daphnia magna

Details on test organisms:

The test organism Daphnia magna Straus originates from the clone breeding of the Federal Environment Agency, department IV 2.4, Berlin, and has been cultivated at Hydrotox GmbH since October 2012. The daphnids are cultured at 20 ± 2 °C with 16 h light : 8 h dark and placed into fresh M4 medium twice a week. They are kept at approx. 10 animals / 200 mL and fed on workdays with Desmodesmus subspicatus algae corresponding to 0.1 mg C × daphnid-1 × day-1. The test organisms used were 0.25 - 22.5 h old at the start of the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The test was performed with M4 medium according to OECD 202 (2004).

Test temperature:

19.7 - 21.1 °C

pH:

The pH was 7.4 - 7.9 in the control and 7.6 - 7.9 in the test item treatment.

Dissolved oxygen:

The dissolved oxygen concentration was 7.8 - 8.2 mg/L in the control and 7.7 - 8.2 mg/L in the test item treatment.

Salinity:

Salinity of M4 medium.

Conductivity:

The test was performed with M4 medium according to OECD 202 (2004).

Nominal and measured concentrations:

The measured TOC-concentrations in the test item treatment were 89.0 – 91.2 % of the nominal concentrations and stable during the exposure period. The TOC-concentrations in the control were below the limit of quantification

Reference substance (positive control):

yes

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Results with reference substance (positive control):

Quality assurance takes place at regular intervals by testing the sensitivity of the test organisms to the potassium dichromate. The recent quality testing was performed in December 2015 with EC50 (24h) = 1.30 mg/L and EC50 (48h) < 1.25 mg/L.

The purpose of this study was to investigate the effects of the test item on Daphnia magna. Daphnids, less than 24 h old, were exposed to one concentration of the test item in M4 medium mfor 48 h. A static test design was applied with an accompanying TOC-analysis. The swimming mcapability of the daphnids was assessed after 24 h and 48 h exposure. A preliminary test without GLP was performed before start of this GLP-study. Nominal concentrations of 10, 40 and 160 mg/L test item were tested and showed no effects on the mobility of the test organisms. In the present study, a single concentration of 100 mg/L test item was used (limit test).

The test vessels were kept in an incubator with 16 h light : 8 h dark for 48 h. The swimming capability of the daphnids was determined after 24 h and 48 h exposure. Animals that did not swim within 15 s after gently moving the test vessel were considered to be immobile. The pH as well as the O2-concentrations were measured at the start (0 h) and at the end of the test (48 h) and the temperature was measured continuously.

The effect occurrence after 24 h and 48 h exposure was calculated. With the statistical software ToxRat Professional 3.2.1 (ToxRat Solutions GmbH, Alsdorf, Germany), LOEC/NOEC were determined.

Nominal test item concentration [mg/l]	Immobility [%]
	24 h	48 h
Negative control	0	0
100	10	15

Validity criteria fulfilled:

yes

Conclusions:

A static Daphnia magna acute immobilisation test was performed using a single concentration of 100 mg/L test item. All results are given in relation to nominal test item concentrations: NOEC >= 100 mg/l and LOEC > 100 mg/l.

Executive summary:

A static Daphnia magna acute immobilisation test was performed using a single concentration of 100 mg/L test item. All results are given in relation to nominal test item concentrations. NOEC was determined to be >= 100 mg/l and LOEC to be > 100 mg/l. The measured TOC-concentrations in the test item treatment were 89.0 – 91.2 % of the nominal

concentrations and stable during the exposure period. The TOC-concentrations in the control

were below the limit of quantification.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

A static Daphnia magna acute immobilisation test was performed using a single concentration of 100 mg/L test item. All results are given in relation to nominal test item concentrations: NOEC >= 100 mg/l and LOEC > 100 mg/l.