AERO 5100 PROMOTER

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:

03 - 07 Aug 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: The solvent control and each test concentration were verified by chemical analysis.
- Sampling method: Duplicate medium samples (200 mL) were taken from the solvent control and each test concentration at 0 and 72 h (fresh media), 24 and 96 h (expired media) for analysis

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The substance was dissolved in ethanol to give an initial stock solution of 100 mg/mL. Serial dilutions of this stock solution were prepared with the auxiliary solvent and aliquots added to the test vessels to give the desired series of test concentrations. Solvent spikes were introduced to the air-tight test vessels via a septum due to the volatile nature of the test compound. Test solutions were mixed thoroughly before the addition of test organisms and extraction of chemistry samples.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Ethanol
- Controls: yes, test medium and solvent control
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 100 µL/L in the solvent control

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: Parkwood Trout Farm, Kent, UK
- Length at study initiation: mean of 4.6 cm (SD = 0.2 cm)
- Weight at study initiation: mean of 1.91 g (SD = 0.33 g)
- Feeding during test: none

ACCLIMATION
- Acclimation period: The stock of fish was obtained from the supplier on 7 Jul 1998 and acclimatised to test conditions from that date.
- Acclimation conditions: similar to test conditions (Temperature remained at 15 °C and dissolved oxygen within the range 7.3 to 9.0 mg O2/L in the 14-day period immediately prior to the study)
- Type and amount of food: fed to repletion with commercial fry pellet but food was not given during the 24 hour period immediately before exposure
- Feeding frequency: daily
- Health during acclimation (any mortality observed): no mortalities were recorded

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

129 - 173 mg CaCO3/L (calculated from daily measurements during acclimatisation)
114 - 147 mg CaCO3/L (throughout the exposure period)

Test temperature:

12.0 - 13.0 °C (at test start)
13.0 °C (at test end)

pH:

7.6 - 7.8 (at test start)
7.1 - 7.2 (at test end)

Dissolved oxygen:

9.8 - 10.0 mg O2/L (at test start)
6.4 - 7.2 mg O2/L (at test end)

Nominal and measured concentrations:

control, 0.46, 1.0, 2.2, 4.6, and 10 mg/L (nominal)
control, 0.38, 0.86, 1.9, and 8.8 mg/L (mean measured)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed (air-tight aquaria)
- Material, size, headspace, fill volume: air-tight cylindrical aquaria (50 cm height x 30 cm diameter) filled with 22.75 L medium, without headspace
- Aeration: Supplementary aeration was provided via narrow bore glass tubes
- 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
- No. of vessels per vehicle control (replicates): 1 (100 µL auxiliary solvent per L)
- Biomass loading rate: 0.59 g body weight per litre (static volume)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The water used for the study was laboratory tap water filtered, dechlorinated and softened by passage through an Elga® water purification system. The water passes in sequence through a high pressure sand filter to remove colloids and particulate matter and a high grade activated carbon filter to remove chlorine and any organic contaminants. A proportion of the supply then passes through a water softener before final reverse osmosis treatment to produce a highly purified water supply. The two grades of dechlorinated water are then remixed in the ratio of approximately 1:1 to give a supply with the desired water hardness.
- Chlorine: 0.01 to 0.15 mg/L (seven days of the acclimatisation period), 0.00 to 0.02 mg/L (during exposure period)
- Intervals of water quality measurement: daily records of temperature, pH and dissolved oxygen

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light : 8 hours dark

EFFECT PARAMETERS MEASURED: Mortality, observed after 0.25, 2, 4, 24, 48, 72 and 96 h; subjective assessments were also made on the type and incidence of sub-lethal effects compared with control fish

TEST CONCENTRATIONS
- Spacing factor for test concentrations: approx. 2.2
- Range finding study: yes
- Test concentrations: 0.01 to 10 mg/L

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 1.9 - 4.1 mg/L (concentrations resulting in 0 and 100% mortality)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.38 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: Marked reactions to exposure (other than death) were increased pigmentation, loss of equilibrium, hyperventilation, lethargy and a tendency to swim predominantly at the surface of the tank.
- Other biological observations: Distension of the abdomen was observed in severely affected organisms due to an accumulation of clear fluid within the digestive tract.

Reported statistics and error estimates:

LC50 values and 95% confidence limits were calculated using the Thompson and Weil model (Thompson, W.R. and Weil, C.S. (1952) Biometrics 8: 51 -54).

Sublethal observations / clinical signs:

Analytical measurements:

Analysis of all test concentrations gave measured concentrations ranging from 82 to 92% of nominal at 0 h, 83 to 88% of nominal at 24 h, 87 to 93% of nominal at 72 h and 81 to 85% of nominal at 96 h.

Environmental parameters:

Environmental parameters (pH and temperature) remained within acceptable limits throughout the duration of the study. Oxygen concentrations were slightly lower than 60% air saturation value after 24 and 48 h as a result of the experimental design for minimisation of chemical loss via volatility. This is not thought to have affected the results of the study.

Table 1: Cumulative mortality data for rainbow trout exposed for 96 hours

Nominal concentration [mg/L]	Mean measured concentration [mg/L]	Cumulative mortality (initial population: 7)
		0.25 h	2 h	4 h	24 h	48 h	72 h	96 h
Control	-	0	0	0	0	0	0	0
Solvent control	ND	0	0	0	0	0	0	0
0.46	0.38	0	0	0	0	0	0	0
1	0.86	0	0	0	0	0	0	0
2.2	1.9	0	0	0	0	0	0	0
4.6	4.1	0	0	0	0	0	7	7
10	8.8	0	0	0	0	4	7	7

ND: None detected

Table 2: Observations on sub-lethal effects of rainbow trout exposed for 96 h

Nominal concentration [mg/L]	Mean measured concentration [mg/L]	Abnormality	Cumulative mortality (initial population:7)
			0.25h	2 h	4 h	24 h	48 h	72 h	96 h
Control	-	NAD
Solvent control	ND	NAD
0.46	0.38	NAD
1.0	0.86	Increased pigmentation						3/7
		Swimming at surface							1/7
2.2	1.9	Hyperventilation						2/7
		Increased pigmentation				2/7	3/7	3/7	5/7
		Lethargy		1/7	1/7	2/7	1/7	2/7	1/7
		Swimming at surface		2/7	2/7	4/7	3/7	2/7
4.6	4.1	Distended abdomen		3/7	3/7		1/7
		Hyperventilation				7/7	7/7
		Increased pigmentation		6/7	6/7	7/7	7/7	A/D	A/D
		Lethargy				1/7	1/7
		Loss of equilibrium					1/7
		Swimming at surface		4/7	7/7	6/7	3/7
10	8.8	Distended abdomen		3/7	3/7	1/7	2/3
		Hyperventilation			7/7	7/7	3/3
		Increased pigmentation	7/7	7/7	7/7	7/7	3/3
		Lethargy		1/7	1/7	3/7	1/3	A/D	A/D
		Loss of equilibrium				1/7
		Lying on bottom				1/7	2/3
		Swimming at surface		6/7	6/7	3/7

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

NAD: No abnormalities detected

A/D: All fish dead

ND: None detected

Table 3: Measured concentrations - Mean values and percentages of nominal

Nominal concentration [mg/L]	Number of samples analysed	Mean measured concentration [mg/L]	% Nominal
Solvent control	4	ND	-
0.46	4	0.38	83
1.0	4	0.86	86
2.2	4	1.9	88
4.6	2	4.1	90
10	2	8.8	88

Table 4: Summary of chemical analysis results

Occasion	Nominal concentration [mg/L]	Measured concentration [mg/L]	Expressed as a % of nominal
0 h	Control	ND	-
	0.46	0.3781	82.2
	1.0	0.8572	85.7
	2.2	1.934	87.9
	4.6	4.245	92.3
	10	8.889	88.9
24 h	Control	ND	-
	0.46	0.3832	83.3
	1.0	0.8485	84.8
	2.2	1.946	88.5
	4.6	3.997	86.9
	10	8.627	86.3
72 h	Control	ND	-
	0.46	0.3980	86.5
	1.0	0.8801	88.0
	2.2	2.040	92.7
96 h	Control	ND	-
	0.46	0.3710	80.6
	1.0	0.8526	85.3
	2.2	1.859	84.5

Table 5: Summary of chemical analysis results - procedural recoveries

Occasion	Fortified concentration [mg/L]	Recovery as a percentage of fortified
0 h	Control	-
	2.61325	99.4
	2.61325	101
24 h	Control	-
	2.61325	97.2
	2.61325	97.9
72 h	Control	-
	2.61325	101
	2.61325	96.3
96 h	Control	-
	2.61325	97.0
	2.61325	99.0
Mean (RSD)		98.6 (1.8)

Description of key information

LC50 (96 h): 2.8 mg/L (arithmetic mean measured concentration, OECD 203)

Additional information

One experimental study is available investigating the short-term effects of the substance to fish (Cytec Industries, 1998). The study was performed according to OECD 203 (GLP) using Oncorhynchus mykiss as test organism. A stock solution of 100 mg/L was prepared in ethanol to prepare the final nominal test solutions of 0.46, 1.0, 2.2, 4.6 and 10 mg/L. In addition a test medium control and solvent control were tested. 100% mortality was recorded at the nominal concentrations of 4.6 and 100 mg/L whereas no mortality was observed at the lower concentrations and in the controls after 96 h. A LC50 (96 h) of 2.8 mg/L (95% CI: 1.9 - 4.1 mg/L) was calculated based on the arithmetic mean measured concentration (GC/FID).