1-hydroxyoctan-2-one

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:

Sept 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

This is a Klimisch 1 rated OECD 202 study conducted on the registered substance according to GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch/Lot number: 1203/16/100

Analytical monitoring:

yes

Details on sampling:

Two samples of 6 mL were taken from both additional vessels (without test organisms in order to not disturb the TOC analysis) of treatment A, C, E and NC after 0 h, 24 h and 48 h exposure for TOC analysis. Of these 4 samples per treatment and sampling time, 2 were analysed directly after sampling and 2 were stored as retain samples in the freezer (≤ -18 °C) until finalisation of the study. For treatment C at 48 h, the two retain samples were measured, including the corresponding NC samples, because the wrong calibration curve was used for the first two samples which resulted in implausible data.

Vehicle:

no

Details on test solutions:

The stock solution was prepared by adding 99.5 mg test item to 1000 mL test medium and shaking for 0.5 h using an overhead shaker. This stock solution was used as highest test item concentration in the test.

Four replicates, with five daphnids each, were prepared for each test item treatment and the negative control (NC; test medium).

The further test item concentrations were prepared by diluting the stock solution with test medium according to the following scheme (dilution factor of 2):

Treatment Group NC A B C D E
Nominal test item concentration [mg/L]* 0 6.25 12.5 25 50 100
Stock solution [mL] 0 15.6 31.3 62.5 125 250
Test medium [mL] 250 234.4 218.7 187.5 125 0
Test vessels (replicates) 4 4 4 4 4 4
Test Solution/Test Medium [mL] 20 20 20 20 20 20
Additional Vessels for TOC analysis 2 2 - 2 - 2
Test Solution/Test Medium [mL] 40 40 - 40 - 40

"*Due to weighting tolerance and measuring inaccuracy of the analytical balance, the nominal test item concentrations
can deviate < 2 % from the target values."

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 Elendt 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 0.5 – 23 h old at the start of the test.

Quality assurance takes place at regular intervals by testing the sensitivity of the test organisms to the reference item potassium dichromate (Sigma, Steinheim, Germany; Lot no.: MKBF2111V). The recent quality testing was performed in April 2018 with EC50 (24h) = 1.8 mg/L (CL 95 %: 1.64 –2.02 mg/L), which is in the declared range of 0.6 – 2.1 mg/L (24 h) according to OECD 202.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.0 – 21.2 °C

pH:

The pH was 7.7 – 8.1 in the control and 7.7 – 8.4 in the test item treatments (i.e. within recommended range of 6 –9)

Dissolved oxygen:

The dissolved oxygen concentration was 8.0 – 8.2 mg/L in the control and 8.0 – 8.3 mg/L in the test item treatment (i.e. meets requirements of ≥ 3 mg/L)

Nominal and measured concentrations:

Nominal Concentrations: 0; 6.25; 12.5; 25; 50; 100 mg/L
Geometric Mean Measured Concentrations (0h, 24h and 48h): X; 5.75; X; 23.88; X; 97.9 mg/L (only 3 out of 5 concentration series was subjected to TOC analysis)

The measured TOC concentrations in the test item treatments were 86.2 – 100.2 % of the nominal TOC concentrations

Details on test conditions:

The test vessels are kept in an incubator (specified temperature 18 – 22 °C, constant within ± 1 °C) with 16 h light : 8 h dark. The pH and the O2-concentrations were measured at the start (0 h) and at the end of the test (48 h). The temperature was measured continuously.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

39.08 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

Immobilisation

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

23.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

Immobilisation

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

12.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

Immobilisation

Details on results:

The measured TOC concentrations in the test item treatments were 86.2 – 100.2 % of the nominal TOC concentrations.

As the measured test item concentrations are within ± 20 % of the nominal concentrations, according to OECD 202 (2004), all results are given in relation to the nominal test item concentrations.

Reported statistics and error estimates:

See results table for 95% Confidence Limits on 48h EC50 and EC10 values

Nominal test item conc [mg/L]	Daphnia Introduced				Immobile Daphnia (replicates 1-4)								Immobility [%]
	0h				24h				48h				24h	48h
	1	2	3	4	1	2	3	4	1	2	3	4
NC	5	5	5	5	0	0	0	0	0	0	0	0	0	0
6.25	5	5	5	5	0	0	0	0	0	0	0	0	0	0
12.5	5	5	5	5	0	0	0	0	0	0	0	0	0	0
25	5	5	5	5	0	0	0	0	0	1	1	1	0	15
50	5	5	5	5	0	1	1	0	4	3	4	3	10	70
100	5	5	5	5	5	5	5	5	5	5	5	5	100	100

Parameter	Nominal test item concentration [mg/L]
	24h	48h
EC50	58.22	39.08
95% CL	n.d	32.5-47.0
EC10	50	23.5
95% CL	n.d	15.9-28.9
LOEC	50	25
NOEC	25	12.5

Validity criteria fulfilled:

yes

Conclusions:

The acute 48h EC50 value for invertebrates (daphnia magna) exposed to 1-hydroxyoctan-2-one was determined to be 39.1 mg/L (nominal).

As the measured test item concentrations are within ± 20 % of the nominal concentrations, according to OECD 202 (2004), all results are given in relation to the nominal test item concentrations.

Executive summary:

The acute toxicity of 1 -hydroxyoctan-2 -one towards the aquatic invertebrate daphna magna was investigated in an OECD 202 guideline study conducted in accordance with GLP including TOC chemical analysis to confirm exposure concentrations (Klimish 1).

The acute 48h EC50 value for invertebrates (daphnia magna) exposed to 1-hydroxyoctan-2-one was determined to be 39.1 mg/L (nominal). As the measured test item concentrations are within ± 20 % of the nominal concentrations, according to OECD 202 (2004), all results are given in relation to the nominal test item concentrations.

Description of key information

The acute toxicity of 1 -hydroxyoctan-2 -one towards the aquatic invertebrate daphna magna was investigated in an OECD 202 guideline study conducted in accordance with GLP including TOC chemical analysis to confirm exposure concentrations (Klimish 1).

The acute 48h EC50 value for invertebrates (daphnia magna) exposed to 1-hydroxyoctan-2-one was determined to be 39.1 mg/L (nominal). As the measured test item concentrations are within ± 20 % of the nominal concentrations, according to OECD 202 (2004), all results are given in relation to the nominal test item concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

39.1 mg/L