Quaternary ammonium compounds, C18-22 (even numbered) alkyltrimethyl, chlorides; Docosyltrimethylammonium chloride; C18-22 TMAC

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

From April 04, 2017 to April 06, 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

KL2 due to RA

Justification for type of information:

Refer to the Quaternary ammonium salts (QAS) category or section 13 of IUCLID for details on the category justification. The study with the read across substance is considered sufficient to fulfil the information requirements as further explained in the provided endpoint summary.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

At the start of the test the excess test solutions were sampled and at the end of the test one replicate of the dilution water control and each test concentration was sampled.

Vehicle:

no

Details on test solutions:

Glass beakers of 250 mL nominal capacity were used as test vessels, with four replicates per test concentration. Each vessel contained 200 mL of test solution providing a depth of approximately 60 mm. The beakers were covered with loose fitting glass lids. The positions of the treatments were randomly allocated within the test area. The test was initiated by the addition of 5 impartially selected D. magna, in <2.0 mL of dilution water, to each test vessel. Each treatment contained a total of 20 D. magna.

This study was run with a dilution water control and nominal exposure concentrations of 5.6, 10, 18, 32, 56 and 100 μg/L.
primary stock concentrate of the test substance with a nominal concentration of 10 mg/L, was prepared by adding a nominal 10 mg of test substance to 1000 mL of dilution water. The concentrate was then placed in an ultrasonic bath for approximately 1 hour. The resultant stock was observed to be a clear and colourless solution and was used to prepare the test solutions. All test solutions were clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

The test organism was the freshwater crustacean, Daphnia magna, obtained from continuous laboratory cultures held at Scymaris.
The stock cultures of D. magna were maintained in a reconstituted water medium, the same as the test dilution water, at a temperature of 20 ± 2 °C. The cultures were maintained in 2 L glass vessels with a working volume of 1.6 L. A photoperiod of 16 hours light:8 hours dark, with 20 minute transition periods was provided.
The D. magna cultures were fed on a mixed algae diet of Chlorella vulgaris, strain CCAP 211/12 and Pseudokirchneriella subcapitata, strain CCAP 278/4. The D. magna cultures were fed daily ad libitum depending on age and density of the culture. Culture conditions were such that the D. magna reproduction was by diploid parthenogenesis.
D. magna <24 hours old, obtained from a single culture vessel, were used for testing. The parent animals were 14 ± 1 day old and had been maintained with a twice weekly renewal of reconstituted water medium since birth. The test organisms and the culture from which they were obtained showed no evidence of disease before the test period.

Test type:

static

Water media type:

other: reconstituted water medium

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20 ± 1 °C

pH:

In control (begining of the experiment): 7.40
In 82 μg/L solution (begining of the experiment): 7.56

In control (48 h): 7.67; 7.81
In 82 μg/L solution (48 h): 7.92; 7.99

Dissolved oxygen:

In control (begining of the experiment): 9.04 mg/L
In 82 μg/L solution (begining of the experiment): 8.92; 8.81 mg/L

In control (48 h): 8.91 mg/L
In 82 μg/L solution (48 h): 8.86; 8.79 mg/L

Conductivity:

Conductivity 615 (μS/cm)

Nominal and measured concentrations:

Control and nominal concentrations of 5.6, 10, 18, 32, 56 and 100 μg/L.
Control and mean measured concentrations of 7.1, 4.7, 9.4, 16, 40 and 82 μg/L.

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

34.46 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval

Remarks:

28.92 – 43.32 μg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

25 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval

Remarks:

19.46 – 28.79 μg/L

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

16 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

40 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

There was no immobility observed in the dilution water control. No other symptoms of toxicity were observed.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions toxicity of the test substance in Daphnia sp. acute immobilisation test was determined to be 48h EC50: 25 μg/L; 48h NOEC: 16 μg/L; 48h LOEC: 40 μg/L.

Executive summary:

A study was conducted to determine the acute toxicity of the read across substance, C16 TMA-MS, (active: 88.75%) to Daphnia magna according to OECD Guideline 202, in compliance with GLP. The study was performed using 5 nominal concentrations of the read across substance ranging from 5.6 to 100 μg/L Glass beakers of 250 mL nominal capacity were used as test vessels, with four replicates per test concentration. Each vessel contained 200 mL of test solution providing a depth of approximately 60 mm. The beakers were covered with loose fitting glass lids. The test was initiated by the addition of 5 impartially selected D. magna, in <2.0 mL of dilution water, to each test vessel. Each treatment contained a total of 20 D. magna. Test solutions were analytically verified by liquid chromatography method, thus toxicity results are concerning measured values. Under the study conditions, the 48 h EC50 of read across substance for toxicity to Daphnia magna was 25 μg/L (i.e., equivalent to 22.3 μg a.i./L). The NOEC and LOEC for effect on daphnia mobility was determined to be 16 and 40 μg/L (i.e., equivalent to 14.2 and 36 μg a.i./L) (Scymaris, 2017). Based on the results of the read across study, similar EC50 value can be considered for the test substance, C18-22 TMAC.

Description of key information

Based on the results of the read across study, the 48 h EC50 of the test substance, C18-22 TMAC, for toxicity to Daphnia magna is considered to be 0.223 mg a.i./L (or 22.3 μg a.i./L) (measured).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.022 mg/L

Additional information

A study was conducted to determine the acute toxicity of the read across substance, C16 TMA-MS, (active: 88.75%) to Daphnia magna according to OECD Guideline 202, in compliance with GLP. The study was performed using 5 nominal concentrations of the read across substance ranging from 5.6 to 100 μg/L Glass beakers of 250 mL nominal capacity were used as test vessels, with four replicates per test concentration. Each vessel contained 200 mL of test solution providing a depth of approximately 60 mm. The beakers were covered with loose fitting glass lids. The test was initiated by the addition of 5 impartially selected D. magna, in <2.0 mL of dilution water, to each test vessel. Each treatment contained a total of 20 D. magna. Test solutions were analytically verified by liquid chromatography method, thus toxicity results are concerning measured values. Under the study conditions, the 48 h EC50 of read across substance for toxicity to Daphnia magna was 25 μg/L (i.e., equivalent to 22.3 μg a.i./L). The NOEC and LOEC for effect on daphnia mobility was determined to be 16 and 40 μg/L (i.e., equivalent to 14.2 and 36 μg a.i./L) (Scymaris, 2017). Based on the results of the read across study, similar EC50 value can be considered for the test substance, C18-22 TMAC, for short-term toxicity to Daphnia.