C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study but without chemical analysis to check the exposure concentrations.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

No chemical analyses to check the exposure concentrations.

Principles of method if other than guideline:

No measurements of concentrations.

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
yellow viscous paste, Freezing point 30 C, Stable at test conditions, water soluble at test conditions

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test solutions were prepared from stock solutions of the test substance in deionized water. The stock solution was prepared by heating the entire sample under stirring to approx 60 C in order to homogenize the sample and then adding the sample to water (approx 80 C) under stirring. By this method a homogenous solution was obtained being slightly viscous at room temperature and a stock solution of 1 g/L was prepared. Before the stock solution was used for the preparation of the test concentrations, the stock solution was warmed up again to approx 40 C under stirring. The test concentrations were prepared by addition of the respective amounts of the stock solution to the Dutch Standard Water (DSW).

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna (waterflea) originated from the continuous culture maintained at the research facilities. The animals used in the test were less than 24 hours old at the beginning of the test and were obtained from parent animals having an age of about 3 - 4 weeks.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

13 dH

Test temperature:

19.0 - 19.6 C

pH:

7.6 - 8.0

Dissolved oxygen:

9.0 - 9.4 mg/L

Nominal and measured concentrations:

Nominal concentrations:
0.1 - 0.22 - 0.46 - 1.0 - 2.2 mg/L

Details on test conditions:

400 mL glass beakers containing 250 mL of test medium were partly covered with a glass plate. Each beaker contained 5 animals. 20 animals were
tested per test concentration and in the control group.
The diluting water used for the preparation of the test concentrations was a synthetic water: Dutch Standard Water (DSW): pH = 8.2 and a hardness of 13 dH. The test was carried out in a temperature controlled room. The light regime was 16 hours of ambient light per day, supplied by fluorescent tubes. pH and oxygen were measured at the beginning and at the end of the test.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.47 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.94 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.75 - 1.17 mg/L (95% CL)

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The NOEC after 48 hours amounted to 0.22 mg/L , whereas 2.2 mg/L produced 100% immobilization within 48 hours. The EC50 (48h) was calculated to be 0.94 mg/L with 95% confidence limits of 0.75 - 1.17 mg/L. Since in the control group also minor mortality was observed (< 10%), the mortality
in the lowest dose group (< 10%) was considered not related to the exposure. Indeed the next dose group (0.22 mg/L) showed no mortality and was therefore considered to be the NOEC.

Reported statistics and error estimates:

The LC50 was calculated with a programme (Akzo programme SKBT, version 1.0) using both the trimmed Spearman-Kärber method and the binomial method.

Number of mobile animals

Conc substance	Test vessel
in mg/l	number	0 hours	24 hours	48 hours
	1	5	5	5
	2	5	5	5
	3	5	5	5
control	4	5	5	4
	total	20	20	19
	1	5	5	5
	2	5	5	5
0.1	3	5	5	5
	4	5	4	4
	total	20	19	19
	1	5	5	5
	2	5	5	5
0.22	3	5	5	5
	4	5	5	5
	total	20	20	20
	1	5	5	4
	2	5	5	4
0.46	3	5	5	5
	4	5	5	4
	total	20	20	17
	1	5	4	3
	2	5	5	5
1.0	3	5	3	2
	4	5	4	1
	total	20	16	11
	1	5	5	0
	2	5	3	0
2.2	3	5	5	0
	4	5	5	0
	total	20	18	0

Validity criteria fulfilled:

yes

Conclusions:

The NOEC 48h could be established since mortality in the lowest dose group was comparable to the mortality in the control group. The EC50(48h)
was calculated to be 0.94 mg/L with 95% confidence limits of 0.75 and 1.17 mg/L. If it is assumed that the product has a 100% pure active ingredient and that the toxicity is related to the active ingredient only, the EC50 and NOEC (48h) amount to 0.47 and 0.11 mg/L amine oxide respectively.

Executive summary:

A static study was performed according to OECD203 and GLP to investigate the acute toxicity of the test item to the aquatic invertebrate Daphnia magna. Based on nominal concentrations only, the EC50 was calculated to be 0.94 mg/L with 95% confidence limits of 0.75 and 1.17 mg/L test substance. The NOEC after 48h was determined at 0.22 mg/L test substance.

Based on Active Ingredient (50.5%) the EC50 = 0.47 mg/L.

Description of key information

The acute toxicity of C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide to daphnia was observed to be 0.47 mg a.i./L based on nominal test concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.47 mg/L

Additional information

A static study was performed according to OECD203 and GLP to investigate the acute toxicity of the test item to the aquatic invertebrate Daphnia magna. Based on nominal concentrations only, the EC50 after 48h was calculated to be 0.94 mg/L with 95% confidence limits of 0.75 and 1.17 mg/L test substance. The NOEC after 48h was determined at 0.22 mg/L test substance.

Based on Active Ingredient (50.5%) the EC50 = 0.47 mg a.i./L.