Reaction mass of 1-Hydroxyoctane, 2-methanoate and 1,2-Dihydroxyoctane, dimethanoate and 2-Hydroxyoctane 1-methanoate and 1,2-Dihydroxyoctane

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:

31 Mar - 25 May 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)

Version / remarks:

2004

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

No. 440/2008

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office for the Environment (FOEN)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: duplicate samples were taken at the start and end of each test medium renewal period from all tested concentrations and from the control
- Sampling method: the contents of the respective replicates were combined prior to sampling at the aged test media.
- Sample storage conditions before analysis: samples were stored deep-frozen (at about -20 °C)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: WAFs were prepared by adding of individual amount of test item for each loading rate, solutions were stirred slowly 24 h to dissolve a maximum amount of the different compounds of the test item. Then the lower equilibrated water phases were carefully removed from each stirring vessel through the tap at the bottom of the vessels while the non-dissolved test item floating on the water surface remained in the stirring vessels.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: laboratory culture
- Age at study initiation: 6-24 h
- Feeding during test: no

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

-

Test temperature:

21 - 22 °C

pH:

7.3 - 7.8

Dissolved oxygen:

8.2 mg/L

Salinity:

-

Conductivity:

-

Nominal and measured concentrations:

Nominal: 1, 3.2, 10, 32 and 100 mg/L (loading rates, WAF)
Measured - first renewal period (0h): not measured, < LOQ = 0.7 mg/L, 2.2, 12.3, 62.3 mg/L
Measured - second renewal period (0h): not measured, < LOQ = 0.7 mg/L, 2.0, 12.9 mg/L, not measured

Details on test conditions:

TEST SYSTEM
- Test vessel: 100-mL glass beakers covered with disposable polypropylene sheets (to reduce evaporation and avoid entry of dust in the solutions)
- Material, size, headspace, fill volume: 50 mL fill volume
- Aeration: test water was aerated prior to the start of the study until oxygen saturation was reached, no aeration during test
- Renewal rate of test solution (frequency/flow rate): every 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: prepared according to ISO 6341
- Ca/Mg ratio: 4:1
- Intervals of water quality measurement: pH, dissolved oxygen and water temperature were determined at the start and at the end of each test medium renewal

OTHER TEST CONDITIONS
- Photoperiod: 16-h light to 8-h dark cycle
- Light intensity: 15 and 18 μmol m^-2 s^-1

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility was determined by visual inspection after 24 and 48 h of exposure

RANGE-FINDING STUDY
- Test concentrations: Loading rate 100 mg/L, 1:10 dilution, 1:100 dilution
- Results used to determine the conditions for the definitive study: 100% immobilization after 48 h observed at the loading rate of 100 mg/L, no mobilisation observed for the 1:10 and 1:100 dilutions

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

8.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 7.2 and 11 mg/L

Duration:

48 h

Dose descriptor:

EL0

Effect conc.:

3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL100

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Details on results:

- Other observations: test media were clear solutions throughout the 24 h renewal periods
- Mortality of control: no

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50 (24 h): 1.6 mg/L (within the range given by the guideline 0.60-2.1 mg/L)

Reported statistics and error estimates:

EL50 and 95% confidence limits were calculated by Weibull Analysis. Statistical analysis was performed using ToxRat Professional®.

Since water accommodated fractions of the test item were tested, all reported biological results were based on the loading rates of the test item.

Measured concentrations at the end of the renewal periods were between 0 and 48% of the initially measured values.

Table 1: Effect of the test item on the mobility of Daphnia magna

Treatment	% Immobilized daphnids after 48 h
Loading rate [mg/L]
Control	0
1	0
3.2	0
10	65
32	100
100	100

Table 2: Analytical results.

Sampling Day / Sample Age [d/h]	Loading Rate of Test Item [mg/L]	Determined Concentration of Test Item [mg/L]
0 (fresh)	Control	< 0.7
	3.2	< 0.7
	10	2.2
	32	12.3
	100	62.3
1/24 (aged)	Control	< 0.7
	3.2	< 0.7
	10	< 0.7
	32	2.4
	100	30.1
1/0 (fresh)	Control	< 0.7
	3.2	< 0.7
	10	2
	32	12.9
2/24 (aged)	Control	< 0.7
	3.2	< 0.7
	10	< 0.7
	32	3.5

Validity criteria fulfilled:

yes

Conclusions:

The test item showed acute toxic effects on Daphnia magna in a 48 h semi-static test resulting in an EL50 of 8.8 mg/L (with 95%-confidence limits of 7.2 and 11 mg/L) based on loading rates.

Executive summary:

The acute toxicity of the test item to Daphnia magna was determined in a 48-hour semi-static test according to OECD 202 (2004) and GLP.

In order to assess the toxicity of the substance containing different components to daphnids, water accommodated fractions (WAFs) with the loading rates of 1.0, 3.2, 10, 32 and 100 mg/L were tested.

Following the slow stirring method, five individual solutions with the corresponding test item loading rate were slowly stirred for 24 hours to dissolve a maximum amount of the different compounds of the test item in the solutions. The stirring period was based on the pre-experiment. The analytical measurements of the soluble components of the test item were based on two main components of the test item, which represent approximately 60% of the test item.

During the test medium renewal periods of 24 hours, a decrease of the analyzed components in the test media occurred. The measured concentrations at the end of the renewal periods were in the range of 0 and 48% of the initially measured values. Since WAFs of the test item were tested, all reported biological results were based on the loading rates of the test item.

Description of key information

EL50 (48 h) = 8.8 mg/L (nominal, WAF), based on mobility of Daphina magna (OECD 202, GLP)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

8.8 mg/L

Additional information

One experimental study is available investigating the short-term effects of the substance to aquatic invertebrates. The study was performed under semi-static conditions according to OECD 202 (GLP) with the water flea Daphnia magna. The test organism was exposed to loading rates of 1, 3.2, 10, 32 and 100 mg/L (WAF) for 48 h. Immobilization of Daphnids was observed after 48 h resulting in an EL50 of 8.8 mg/L (loading rate, WAF). Since water accommodated fractions of the test item were tested, the reported biological results were based on the loading rates of the test item.