Fatty acids, C18 unsat, reaction products with diethylenetriamine

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:

March 24 2007 to May 5 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD 202 guideline study, GLP, All validity criteria fulfilled, complete identification of test substance, including chemical analyses

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures. OECD Environmental Health and Safety Publication, Series on Safety testing and assessment, No. 23, Paris (December 2000)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples: 6
Storage of samples: none
Samples treatment: dilution in methanol with a dilution factor ranging from 2 to 10

Vehicle:

no

Details on test solutions:

Osmotically filtered water was used to prepare the dilution water, using analytical grade reagents.

Test solutions
A stock solution of IMIDAZOLE 4900 diluted in water was prepared at the beginning of the tes time (time 0) by mixing 10 mg of IMIDAZOLINE 4900 in one liter of dilution water. After 24h stirring, solution was filtered through HAWP04700 Millipore membrane to obtain limpid solutions.
Volumetric flasks were filled with the required volumes of this test item stock solution and dilution water was added in order to obtain the test solutions at different concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

Biological reagent: organisms Daphnia magna Straus (Cladocera, Crustacea) clone 5 or clone A. Animals come from a stock breeding in the laboratory reared in VOLVIC water added with vitamin B12, Na2SeO3.5H2O, spirulline, calcium, magnesium, unicellular green freshwater algae Pseudokirchnerielle subcapitata and Chlorella vulgaris. Selection of test organisms less than 24 hours old is made by filtration.

The sensitivity of the test system and the methodology are evaluated every month by performing an inhibition test on potassium dichromate. The nearest value of EC50 obtained on 31/05/2007 was 0.95 mg/L. For reference, ISO 6341 has a validity criteria specifying that EC50 must be in the range of 0.6 to 2.1 mg/L

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

Preliminary test: 19.3 ± 1 deg celsius
Definitive test: 19.8 ± 1 deg celsius

pH:

7.98 to 8.15

Dissolved oxygen:

8.5 to 9.6 mg/L

Salinity:

not relevant for freshwater tests

Nominal and measured concentrations:

Preliminary test
Nominal: 0.05; 0.5; 1; 5; 10; 10; 50 mg/L
Measured (initial) 0.045; 0.426; 0.93; 4.27; 8.13; 48 mg/L
Measured (final) 0.02; 0.33; 0.73; 3.02; 5.34; 17.54 mg/L
Final/intial (%); 44.4; 77.5; 78.5; 70.7; 65.7; 36.5

Definitive test
Nominal: 0.048; 0.076; 0.122; 0.195; 0.313; 0.5 mg/L
Measured (initial) 0.051; 0.078; 0.157; 0.326; 0.433; 0.692 mg/L
Measured (final) 0.040; 0.060; 0.080; 0.217; 0.292; 0.535 mg/L
Geometric means 0.045; 0.068; 0.112; 0.266; 0.355; 0.608 mg/L

Details on test conditions:

The study was performed in a temperature controlled room using 30 mL glass bottles stoppered with PTFE bungs and sealed with aluminium caps. The temperature, continuously recorded in one test flask, remained near 20 deg. celsius.
Physico-chemical parameters were measured using a METTLER TOLEDO 345 pH meter for measurement of pH and with a WTW OXI 538 oxymeter for dissolved oxygen measurements.

Preliminary test
Daphnids were exposed to 6 concentrations under static conditions (50, 10, 5, 1, 0.5, 0.05 mg/L) of IMIDAZOLINE 4900 in dilution water. The toxic effect measured during the assay was the inhibition mobility over a time period of 48 hours.
Approximately 90% of the test volume of the test solution was added into the test flasks. 5 Daphnia magna aged from 6 to 24 hours were added into each test flask, which were then totally filled with the test solution (30 mL). Two replicates were prepared for each test concentration. Two control flasks were prepared under the same conditions with no test item. Test flasks were incubated in darkness at a temperature of 19.3 ± 1 deg. celsius.

Definitive test
Based on the results of the preliminary test, the concentrations tested were: 0.5; 0.313; 0.195; 0.122; 0.076; 0.048 mg/L. (geometric progression factor 1.6).
At the beginning of the test, appropriate volumes of the stock solution were poured directly into the test aquarium. They were then topped up with dilution waster to obtain the above mentioned range of nominal concentrations, with no pH adjustments.
Approximately 90% of the final volume of the test solution was added into test flasks. 5 Daphnia magna aged from 6 to 24 hours were added into each test flask, which were then totally filled with the test solution (30 mL). 4 replicates were prepared for each concentration. 4 control flasks were prepared under the same conditions, with no test item. Test flasks were incubated in darkness at a temperature of 19.8 +- 1 deg. celsius,
After 24 hours of incubation, mobile D. magna were counted and flasks replaced under incubation. at 48 hours the Daphnids were also counted.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.42 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.33 - 0.61 (95% CI)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.18 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.18 - 0.35 (95% CI)

Details on results:

The appearance of the test solutions was visually checked at the beginning and at the end of the test. Solutions were found to be clear, colourless over the period of the test. No precipitation was observed at the end of the test.

Results with reference substance (positive control):

The nearest value of EC50 obtained on 31/05/2007 was 0.95 mg/L with potassium dichromate, which is within the ISO 6341 acceptable range of 0.6 to 2.1 mg/L .

Reported statistics and error estimates:

The EC50 values were calculated using Probit analysis in an Excel sheet. The NOEC was determined using the Dunnett's test.

Range find test: Percentage of Daphnia magna immobilisation

Nominal concentrations (mg/L)	Immobilisation (%)
	24 h	48 h
0.05	0	0
0.5	10	100
1	100	100
5	100	100
10	100	100
50	100	100

Definitive test: Percentage of Daphnia magna immobilisation

Geometric mean concentrations (mg/L)	Immobilisation (%)
	24 h	48 h
0	0	0
0.045	0	0
0.068	0	0
0.112	0	10
0.266	15	70
0.355	45	100
0.608	75	100

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of IMIDAZOLINE 4900 to Daphnia magna was assessed under static conditions according to the OECD 202 guideline, and resulted in the following EC50 values
24 h EC50 = 0.42 mg/L
48 h EC50 = 0.18 mg/L

Executive summary:

Summary

The acute toxicity (inhibition of mobility) of the test item IMIDAZOLINE 4900 for a duration of 48 hours was assessed according to the OECD guideline 202.

Daphnia magna were exposed under static conditions to a range of concentrations of IMIDAZOLINE 4900 dissolved in dilution water. The toxic effect measured during the assay was the inhibition of mobility time periods of 24 and 48 hours.

The concentration of test item causing a 50% reduction in mobility (EC50) was estimated.

The results were as follows:

Duration of exposure period (h)	EC50 value, mg/L (95% CI)
24	0.42 (0.33 – 0.61)
48	0.21 (0.1 – 0.35)

C.I.: confidence interval

The study was performed in compliance with the following criteria:

• The immobilisation in the control did not exceed 10% at the end of the test;
• Daphnids in the control were not trapped at the surface of the water;
• The dissolved oxygen concentration remained above 3mg/L over the test period.

Description of key information

One short-term toxicity to aquatic invertebrates study is available for the DETA based alkyl amidoamines/imidazolines which gave the following result: EC50 (48h): 0.18 mg/L test mat. (meas. (geom. mean)) based on: mobility (0.18 - 0.35 (95% CI)). In addition to the study from Gancet (2009) a number of higher tier chronic invertebrate studies were performed. The 21d parental EC50 values can be used as worst-case acute endpoints.  

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

0.18 mg/L

Additional information

Like for the acute fish studies, most of the short-term daphnia tests were conducted in a period when no reliable specific method of analyses was available. Hence, most of the tests were considered to be valid with restrictions. The available short-term daphnia toxicity data on alkyl amidoamines/imidazolines is presented in the Table below. The key study is the most recent study from Gancet (2009). No significant difference in toxicity in the refined test with river water has been observed between the different amidoamine/imidazoline products. In addition to the available acute studies it was decided to perform a number of higher tier chronic invertebrate studies as the substances are poorly soluble in water and exposure in most acute tests was not quantified. The 21d EC50 values should be used as short term endpoints as a worst-case.