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

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6 August - 25 September 1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No measurements of test concentrations.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

No geometric dose step, no measurement of actual concentrations

Principles of method if other than guideline:

No geometric dose step, no measurement of actual 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 melted test substance to hot water (approx 80C) under stirring. By this method a homogenous solution was obtained 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 DutchStandardWater (DSW).

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Obtained from a local aquarium retailer and identified by batch 13-8-90. The fish were appromiximately 2.2-3.0 cm in size and the medium wet weight per fish was approximately 0.18 g.
Before being used in the test, the fish were kept for at least 12 days in the facilities to determine the acceptability of the batch. The water they were kept in was Dutch Standard Water (DSW).

The fish were fed daily, the last feeding taking place 24 hours before the start of the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

13 dH

Test temperature:

23.5 -24.4 C

pH:

8.0 - 8.2

Dissolved oxygen:

7.8 - 9.0 mg/L

Nominal and measured concentrations:

Nominal concentrations:
0.75 - 1.0 - 1.3 - 1.8 - 2.4 mg/L

Details on test conditions:

10 fish were used per test concentration and control: approximately 0.42 g biomass/L.

As test vessels 5 L glass aquaria containing 3L of test medium were used, which were covered with a plass plate. The diluting water used for
preparation of the test concentrations was a synthetic water: Dutch Standard Water (pH= 8.2, hardness: 13 dH).

The test was carried out in a temperature controlled incubator. The light regime was 12 hours of ambient light per day, provided by fluorescent
tubes. Oxygen and pH were measured daily.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

2.13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 2.02 - 2.24 mg/L (95% CL)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

2.08 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.80 - 2.40 mg/L (95% CL)

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.71 - 2.11 mg/L (95% CL)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 1.71 - 2.11 mg/L (95% CL)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Details on results:

The LC50 (96h) was calculated to be 1.9 mg/L with 95% confidence limits of 1.71 and 2.11 mg/L. The highest concentration causing no mortality (No Observed Effect Concentration, NOEC) after 96 hours amounted to 1.3 mg/L, whereas 100% mortality was produced within 26 hours at 2.4 mg/L. No other effects (deviations in behaviour or appearance) were observed.

Results with reference substance (positive control):

The LC50 for potassium dichromate was calculated to be:
mg/L (95% CL)
24h: 224 (169 -298)
48h: 201 (197 -796)
72h: 180 (139 - 234)
96h: 180 (139 - 234)

The results obtained are in accordance with test results from a reference EEC study: mean LC50 (48h) = 205.5 mg/L

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.

Sublethal observations / clinical signs:

Number of surviving animals

Conc (mg/L)	0h	2h	5h	20h	24h	26h	45h	48h	52h	67h	72h	77h	92h	96h
Control	7	7	7	7	7	7	7	7	7	7	7	7	7	7
0.75	7	7	7	7	7	7	7	7	7	7	7	7	7	7
1.0	7	7	7	7	7	7	7	7	7	7	7	7	7	7
1.3	7	7	7	7	7	7	7	7	7	7	7	7	7	7
1.8	7	7	7	7	7	7	7	7	7	5	5	5	5	5
2.4	7	7	7	1	1	0

Validity criteria fulfilled:

yes

Conclusions:

The LC50(96h) was calculated to be 1.9 mg/L with 95% confidence limits of 1.71 and 2.11 mg/L and the NOEC is 1.3 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 LC50 and NOEC (96h) amount to 0.95 and 0.65 mg/L amine oxide respectively.

Executive summary:

A study was performed according to OECD203 and GLP to investigate the acute toxicity of Aromox T/12 to fish. The study was semi-static and was performed also using a reference substance (potassium dichromate). Based on nominal concentrations only, the LC50 was calculated to be 1.9 mg/L and the NOEC 1.3 mg/L. The reference substance showed the acceptability of both the test system and batch of fish. No other effects such as deviations in behaviour or appearance of the fish were observed.

Description of key information

The acute toxicity of C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide to fish was observed to be 0.95 mg a.i./L based on nominal test concentrations.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.95 mg/L

Additional information

A study was performed according to OECD203 and GLP to investigate the acute toxicity of C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide to fish. The study was semi-static and was performed also using a reference substance (potassium dichromate). Based on nominal concentrations only, the LC50 was calculated to be 1.9 mg/L or 0.95 mg a.i./L and the NOEC 1.3 mg/L or 0.65 mg a.i./L. The reference substance showed the acceptability of both the test system and batch of fish. No other effects such as deviations in behaviour or appearance of the fish were observed.