Fatty acids, tall-oil, 1-methyl-1,2-ethanediyl esters

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

(1992)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

(2008)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: nominal 100, 45.5, 20.7, 9.39, and 4.27 mg/L and control
- Sampling intervals: start and end of the renewal periods
- Sampling method: two samples (ca. 50 mL) were taken from each vessel of the freshly prepared (0 and 72 hours) and expired (24 and 96 hours) control and test media.
- Sample storage conditions before analysis: no storage prior to analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: water accommodated fraction (WAF)
The test material (3000, 1365, 621, 281.7 or 128.1 mg) was added to dilution water (ca. 20 L) in an aspirator (30 L), and then made up to volume. Each bulk preparation was stirred for approximately 24 hours in the dark and then left to stand for approximately 24 hours in the dark. An aliquot (1 L) of the mid-vessel portion was syphoned from the preparation vessel and discarded; a further 20 L was then siphoned into an aquarium to provide the Water Accommodated Fraction (WAF).

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source:commercial fish farm in the UK
- Length at study initiation: 4.58 cm (mean total length)
- Weight at study initiation: 1.36 g (mean wet weight)
- Feeding during test: none

ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): same, except that the stock of fish was held under flow-through conditions
- Type and amount of food: commercial fish food (Nutra Fry 02, TROUW (UK) Ltd.); amount equivalent to 1% of the total wet-weight of fish in the holding tank; no food was given during the 24-hour period immediately before exposure.
- Health during acclimation: no medication, no mortality

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

161 mg/L as CaCO3

Test temperature:

14-15 °C

pH:

7.9-8.2

Dissolved oxygen:

90-101% air saturation value

Nominal and measured concentrations:

nominal loading rate: 4.27, 9.39, 20.7, 45.5 and 100 mg/L as WAF
mean measured TOC levels (after background correction):
in fresh media (at 0 and 72 h): 0.32-5.3 mg C/L (control mean: 1.1 mg C/L)
in expired media (at 24 and 96 h): 0.30-4.9 mg C/L corresponding to 70-105% of the starting values (control mean: 1.4-1.7 mg C/L);
overall geometric mean value: 0.344, 0.795, 1.17, 2.96 and 4.95 mg C/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria, containing 20 litres of medium to a depth of 18 cm.
- Type: open
- Aeration: yes
- Renewal rate of test solution: daily
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.48 g body weight/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: laboratory tap water, dechlorinated and softened by passage through a water purification system consisting of activated carbon filter, water softener and reverse osmosis treatment.
Total organic carbon: 1.1 mg C/L
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light : 8 hours dark with periods of subdued lighting at the beginning and end of each light phase

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality and sub-lethal effects; recorded at approx. 2, 4, 24, 48, 72 and 96 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.2
- Range finding study
- Test concentrations: nominal loading rates 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: No mortality or treatment-related effects after 96 hours at 1 and 10 mg/L WAF. At 100 mg/L WAF, one single mortality with treatment-related effects (dark body and eye orbital area, hyperventilation and surface swimming) was observed, being exhibited from 72 hours.

Reference substance (positive control):

not required

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: results are expressed in terms of loading rates

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

45.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: morphology and behaviour

Remarks on result:

other: results are expressed in terms of loading rates

Details on results:

- Other biological observations: darkened pigmentation and hyperventilation (see Table 1)
- Mortality of control: zero
- Other adverse effects control: none
At all concentrations, the test media were colourless.

Reported statistics and error estimates:

The “no observed effect loading rate” (NOELR) was derived by direct inspection of the data for lethal and treatment-related effects effects. An incidence rate of more than one affected fish per group was considered to be significant.

Sublethal observations / clinical signs:

Table 1: Sub-lethal effects

Nominal loading rate (mg/L)	Abnormality	Initial population = 7 fish / concentration
		2 h	4 h	24 h	48 h	72 h	96 h
Control	No abnormalities detected	7/7	7/7	7/7	7/7	7/7	7/7
4.27	No abnormalities detected	7/7	7/7	7/7	7/7	7/7	7/7
9.39	No abnormalities detected	7/7	7/7	7/7	7/7	7/7	7/7
20.7	No abnormalities detected	7/7	7/7	7/7	7/7	6/7	7/7
	Darkened pigmentation	-	-	-	-	1/7*	-
45.5	No abnormalities detected	7/7	7/7	7/7	7/7	7/7	7/7
100	No abnormalities detected	7/7	7/7	7/7	6/7	6/7	4/7
	Darkened pigmentation	-	-	-	1/7	1/7	2/7
	Hyperventilation	-	-	-	-	-	3/7

x/y Number of fish affected / number of fish surviving

* Observation not considered significant as this only occurred in one fish at a single time point, and no sub-lethal effects were observed at the next highest concentration.

Validity criteria fulfilled:

yes

Remarks:

mortality of control animals <10%; concentration of dissolved oxygen in all test vessels >60% saturation

Description of key information

96-h LL50 (based on loading rates) >100 mg/L for Oncorhynchus mykiss (OECD TG 203, EU C.1

Additional information

LL50 for freshwater fish >100 mg/L.

The results indicate that the test material is not toxic to rainbow trout up to the limits of its water solubility (<1 mg/L) and a NOEC and thus a PNEC cannot be determined.