Butylamine

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

4 instead of 5 concentrations, no concurrent untreated control group, instead fish stock taken as reference; feeding was stopped 48 hours before testing instead of 24 h;

Principles of method if other than guideline:

Method based on US national standard

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Fish were placed in the test vessels prior to addition of the test substance (dilutions in distilled water).
- Nominal concentrations were applied independent of solubility; however, due to the full miscibility of n-butylamine with water a non-dissolved test item fraction can be excluded.

The following nominal test item concentrations were used for the test:
10, 32, 50, and 79 mg/L

No pH is reported for the nominal test item concentrations applied. Obviously no adaption of pH to neutral values was performed. Due to the high pKa of the test item (pKa 10.8), toxic effects due to alkaline pH cannot be excluded.

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: bluegill sunfish
- Source: commercial hatchery (N.Y.)
- Age at study initiation (mean and range, SD):
- Length at study initiation (range): 33 - 75 mm
- Feeding during test: no


ACCLIMATION
- Acclimation period: 14 d; any group showing >5% mortality was discarded from testing.
- Diet: commercial food, supplemented with minced frozen shrimp.
- Type and amount of food: no feeding 48 h prior to testing

Disease prevention
Treatment in case fish were in contact with unhealthy fish, performed before acclimiation:
- dilute bath of potassium permanganate for 15 minutes, followed by rinsing;
- immersion in Tetracycline HCl solution (250 mg/gal.) for 24 hours;
if no evidence of desease was observed afterwards, fish were used for testing.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

55 mg/L (CaCO3)

Test temperature:

23 °C

pH:

no data, measured at termination (96 h)

Dissolved oxygen:

checked daily, mild aeration started if needed, but not during the first 24 hours

Nominal and measured concentrations:

10, 32, 50, and 79 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: 19 glass tanks (5 gallons) with 15 cm water level
- Type (delete if not applicable): open
- Aeration: after 24 h, only provided in cases where low oxygen levels had been observed (valve adjusted modest bubbling through air stones, intermittent, on demand).
- No. of organisms per vessel: no data
- No. of vessels per concentration (replicates): no data
- Total No.of organisms per concentration level: at least 10 (% survival is given down to 10%, and graded into 10% steps)
- No. of vessels per control (replicates): none
- No controls were run concurrently. The estimated mean mortality rate of the control fish in the stock tanks was 1.3%.
- Biomass loading rate: <= 1g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: potable well water (underground source): pH 7.6 to 7.9; hardness of 55 mg/L (as CaCO3)
- water collected weekly and stored at a uniform temperature in clean polyethylene vessels.


OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: no data
- Temperature: air conditioned room set at 23°C


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality, daily; dead fish removed immediately;


TEST CONCENTRATIONS
- Spacing factor for test concentrations: factor 3.2 from lowest to next concentration (10 to 32 mg/L), then factor of 1.575;
- Test concentrations: 10, 32, 50, and 79 mg/L (nominal) n-Butylamine.

Reference substance (positive control):

no

Remarks:

but all the other compounds tested in parallel may be taken as a positive control.

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

other: LC90

Effect conc.:

79 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

The LC50 was derived graphically in a semilogarithmic plot.

Sublethal observations / clinical signs:

Summary of mortality data

Concentration, nominal	Mortality [%] after
[mg/L]	24h	48h	72h	96h
Control	--	--	--	--
10	0	0	0	0
32	20	50*	40*	50
50	20	30	50	80
79	20	80	90	90

* inconsistent result (not explained)

Validity criteria fulfilled:

yes

Remarks:

Probably fulfilled - see IUCLID section "Overall remarks, attachments" for details

Conclusions:

LC50 (96 h; Lepomis macrochirus; static; nominal) = 32 mg/L (publication, equivalent to OECD 203; RL2)

Executive summary:

Toxicity of n-butylamine to freshwater fish was assessed in a published study testing 47 industrial chemicals for fish toxicity (Dawson et al., 1975). The study was performed equivalent to OECD 203 with acceptable restrictions (RL2). The tested freshwater species was Bluegill (Lepomis macrochirus), and at least 10 fish were tested per concentration (4 test item concentrations (nominal) applied: 10, 32, 50, and 79 mg/L). No analytical conformation of test item concentrations was performed. However, based on the very high water solubility of the compound (miscible with water), the very low adsorption potential (experimentally determined Koc from batch-equilibrium test: ca.49 L/kg) and being not volatile (fully ionized at environmental pH) it may be assumed with high confidence that the test item was stable during the test. While not all validity criteria specified in OECD 203 could be assessed directly, taking all information given into account, it is very probable that all validity criteria were met. While pH was measured, it was not reported. Thus, based on a pKa of 10.8 (for alkaline functional group) and unbuffered test medium, alkaline pH could have contributed or even have been causative for observed toxicity. The derived LC50 may therefore be regarded as conservative.

Results:

Only at the lowest test item concentration applied (10 mg/L), no mortality was observed during the 96 h of the test. At 32, 50, and 79 mg/L 50%, 80%, and 90 % mortality was observed, respectively, after 96 hours. The LC50 (96 h) was identified as 32 mg/L.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted 1992

Deviations:

yes

Remarks:

no concurrent untreated control group, instead fish stock taken as reference; feeding was stopped 48 hours before testing instead of 24 h;

Principles of method if other than guideline:

Method: based on US national standard

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Fish were placed in the test vessels prior to addition of the test substance (dilutions in test medium).
- Nominal concentrations were applied independent of solubility; however, due to the full miscibility of n-butylamine with water a non-dissolved test item fraction can be excluded.
The following nominal test item concentrations were used for the test: 10, 18, 32, 50, and 100 mg/L;

No pH is reported for the nominal test item concentrations applied. Obviously no adaption of pH to neutral values was performed. Due to the high pKa of the test item (pKa 10.8), toxic effects due to alkaline pH cannot be excluded.

Test organisms (species):

Menidia beryllina

Details on test organisms:

TEST ORGANISM
- Common name: Tidewater silversides, also known as Inland silverside (Menidia beryllina)
- Source: wild caught
- Holding: 30 gallon fish aquaria equipped with aeration and charcoal filters. Aquarium water was periodically freshened by partial changing with "new" water. Diatom filters were used at intervals to supplement the filtering of the charcoal filters.
- Length at study initiation (range): 40 - 100 mm
- Feeding during test: no


ACCLIMATION
- Acclimation period: 14 d;
- Type and amount of food: no feeding 48 h prior to testing
- Health criteria: < 5 % mortality
- Feed: on minced frozen shrimp diet

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

55 mg/L (CaCO3) used as base plus synthetic seawater mix

Test temperature:

20 °C

pH:

no data, measured at termination (96 h)

Dissolved oxygen:

checked daily, no data

Salinity:

specific gravity 1.018

Nominal and measured concentrations:

10, 18, 32, 50, and 100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: 19 glass tanks (5 gallons) with 15 cm water level
- Type (delete if not applicable): open
- Aeration: yes, continuous
- number of animals: no data, probably 20 per concentration (see data on results: "5 %" mortality)
- No. of organisms per vessel: no data
- No. of vessels per concentration (replicates): no data
- No. of vessels per control (replicates): none
No controls were run concurrently. The estimated mean mortality rate of the control fish in the stock tanks was 3 %.
- Biomass loading rate: =< 1g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: potable well water (underground source): pH 7.6 to 7.9; hardness of 55 mg/L (as CaCO3)
- water collected weekly and stored at a uniform temperature in clean polyethylene vessels (no further analytical data)
- supplemented with a synthetic seawater mix


OTHER TEST CONDITIONS
- Adjustment of pH: not reported, most probably no: from the section on behavoiur of test chemicals during test it becomes clear that no specific considerations on test items were made, e.g. it was neither accounted for solubility nor for volatility.
- Photoperiod: no data


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality daily; dead fish removed immediately;


TEST CONCENTRATIONS
- Spacing factor for test concentrations: approx. 1.5 - 2

Reference substance (positive control):

no

Remarks:

but all the other compounds tested in parallel may be taken as a positive control

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

24 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

The LC50 was derived graphically in a semilogarithmic plot.

Sublethal observations / clinical signs:

Summary of mortality data

Concentration, nominal	Mortality [%] after
[mg/L]	24h	48h	72h	96h
Control	--	--	--	--
10	0	0	0	0
18	0	0	25	35
32	0	67	67	67
50	5	40	100	-
100	0	0	100	-

Validity criteria fulfilled:

yes

Remarks:

Probably fulfilled - see IUCLID section "Overall remarks, attachments" for details

Conclusions:

LC50 (96 h; Menidia beryllina, marine water; static; nominal) = 24 mg/L (publication, equivalent to OECD 203; RL2)

Executive summary:

Toxicity of n-butylamine to coastal fish (marine/salt water) was assessed in a published study testing 47 industrial chemicals for fish toxicity (Dawson et al., 1975). The study was performed equivalent to OECD 203 with acceptable restrictions (RL2). The tested salt water species was Tidewater Silverside (Menidia beryllina), and at least 20 fish were tested per concentration (5 test item concentrations (nominal) applied: 10, 18, 32, 50, and 100 mg/L). No analytical conformation of test item concentrations was performed. However, based on the very high water solubility of the compound (miscible with water), the very low adsorption potential (experimentally determined Koc from batch-equilibrium test: ca.49 L/kg) and being not volatile (fully ionized at environmental pH) it may be assumed with high confidence that the test item was stable during the test. While not all validity criteria specified in OECD 203 could be assessed directly, taking all information given into account, it is very probable that all validity criteria were met. While pH was measured, it was not reported, and adaption of pH obviously was not performed. Thus, based on a pKa of 10.8 (for alkaline functional group) and unbuffered test medium, alkaline pH could have contributed or even have been causative for observed toxicity. The derived LC50 may therefore be regarded as conservative.

Results:

Only at the lowest test item concentration applied (10 mg/L), no mortality was observed during the 96 h of the test. At 18, 32, 50, and 100 mg/L 35%, 67%, 100% and 100 % mortality was observed, respectively, after 96 hours. The LC50 (96 h) was identified as 24 mg/L.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

06 May 1985

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

not applicable

Principles of method if other than guideline:

US national guideline

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

Sampling day 0, 1, 2, 3, and 4, sampled at approximately mid-depth;
Analysis of samples either immediately or samples adequately preserved for later analysis.

Vehicle:

no

Details on test solutions:

Perparation of diluted stocks: in 18.9 L stainless steel carbonation vessels. Lake Superior water plus the liquid toxicant were added to the vessels and stirred or blended vigorously.
pH was adjusted to approximately that of Lake Superior water (pH 7.8) when the pH of the stock was outside of the 7 to 8 range, using either NaOH or concentrated HCl.

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnow, cultured at the U.S. EPA Environmental Research Laboratory-Duluth and the University of Wisconsin-Superior campus
- Age at study initiation (mean): 30 d
- Length at study termination (length definition, mean, and SD): 16.5 +- 2.1 mm
- Weight at study termination (mean, SD): 0.067 +- 0.029 g
- Method of breeding: fish had been reared in flow-through tanks; larvae were fed 40-48 hr old brine shrimp nauplii (Bio-Marine Research, Inc., Hawthorne, CA) in excess two times daily (once on week-end days). Embryos and larvae were cultured in water from the same source as used in the exposures to the test chemicals.
- Feeding during test: test fish were not fed 24 hr before or during a test.


ACCLIMATION
- Acclimation period: not needed, holding under same concitions as used for actual test.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

45.8 +-1.3 mg/L (CaCO3)

Test temperature:

25.8 +-0.4 °C

pH:

7.55 +- 0.08 (pH of the stock solution was neutralised with hydrochloric acid)

Dissolved oxygen:

6.7 +- 0.15 mg/L

Salinity:

Alkalinity: 42.9 +- 1.2 mg/L (CaCO3)

Nominal and measured concentrations:

Nominal concentrations tested: nominal: 0, 263, 404, 621, 956, and 1470 mg/L
Analytically determined arithmetic mean values for each concentration and the control were corrected for percent recovery determined from fortified samples. For this test, recovery was 102.8 % (SD +/- 2.8).
Analytical resutls (corr.): <1.95, 219, 357, 498, 711, and 1247 mg/L (n = 5 for each test concentration).

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): covered
- Material, size, headspace, fill volume: test volume 1 L
- Aeration: not needed, flow through

Type of flow-through (e.g. peristaltic or proportional diluter):
- continuous-flow modified mini-diluter: 29 mL/min flow rate;
- stock solution (3600 mg/L) adequately diluted by stirring (no further details);
- Renewal rate of test solution (frequency/flow rate): 14 L/d
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: mean 1.34 g/L or 0.096 g/L/d


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Lake Superior water, filtered through sand and a commercial filter. More than 15 parameters were determined, beyond others Cu (0.3-3.2 µ/L), Zn (1.0-2.7 µg/L), Ni (<0.5 µg/L), Pb (7-20 µg/L), Al (1-26 µg/L).
- oxygen concentrations: measured daily in the five treatments and the control exposure chambers during the 96 hr test.
- Total hardness and total alkalinity measurements were made on the control (approximately 45 mg/L as CaCO3 ), low, medium, and high exposure chambers once for each test.
- Measurement of pH: daily in the five treatment and control exposure chambers.


OTHER TEST CONDITIONS
- Adjustment of pH: yes, in stock solution, pH adjusted to that of the lake water
- Photoperiod: no data


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): behaviour, appearance, mortality, observed after 4, 24, 48, 72, and 96 hr.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.536
- Test concentrations: 0, 263, 404, 621, 956, and 1470 mg/L

Reference substance (positive control):

not required

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

268 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

268 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: loss of equilibrium

Remarks:

(inability to maintain an upright position when swimming)

Details on results:

- Behavioural abnormalities:
Affected fish lost schooling behaviour and kept swimming at the tank surface, were hyperactive, had increased respiration and lost equilibrium prior to death.
- Observations on body length and weight: no
- Other biological observations: no
- Mortality of control: none
- Other adverse effects control: none
- Abnormal responses: not reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Reported statistics and error estimates:

The estimated LC50 (lethal concentration causing 50% mortality of the fish) and EC 50 (effect concentration causing 50% of the fish to show an effect) with corresponding 95% confidence intervals were calculated using the corrected averages of the analyzed tank concentrations and the Trimmed Spearman-Karber Method (Hamilton et al., 1977).
In this case, 95% confidence intervals could not be calcluated because there was no exposure concentration which was of 0% effect (15% mortality at the lowest test item concentration).

Sublethal observations / clinical signs:

Overview of mortality over time

Concentration, analytical	Number of fish	Number of dead fish after
[mg/L]	start	24h	48h	72h	96h
Control (<1.94)	20	0	0	0	0
219	20	0	0	2	3
357	20	0	2	15	20
498	20	1	13	20	20
711	20	1	20	20	20
1247	20	20	20	20	20

Validity criteria fulfilled:

yes

Remarks:

(OECD 203: O2, pH (valid), survival of control 100 %, test concentration stable)

Conclusions:

LC50 (Pimephales promelas; 96 h; flow through; arithmetic mean measured) = 268 mg/L
EC50 (Pimephales promelas; 96 h; flow through; arithmetic mean measured; loss of equilibrium) = 268 mg/L

Executive summary:

In a reliable study (RL 1), acute fish toxicity of n-butylamine was determined using Pimephales promelas (Fathead Minnow) in a flow-through design (14 exchanges per day) with daily measurements of test item concentrations (incl. day zero). Arithmetic mean measured values (n= 5) for the five nominal concentrations were between 74% and 88% of nominal, and above 80% for all but the second highest concentration applied. Effect concentrations were determined base on arithmetic mean measured concentrations. Besides mortality, effects on behaviour and appearance were observed after 4, 24, 48, 72, and 96 hr.

The tested compound n-butylamine is a strong base (pKa 10.8), such that after preparation the stock solution was neutralized to the average pH of the testing water (Lake Superior water, filtered before use and analysed for range of critical parameters) using concentrated HCl. The measured pH during testing was on average 7.55 (SD 0.08).

All validity criteria of OECD 203 (1992) were fulfilled.

Results:

Observed non-lethal effects were loss of schooling behaviour, swimming near surface, hyperactivity, increased respiration, and loss of equilibrium prior to death.

LC50 (Pimephales promelas; 96 h; flow through; arithmetic mean measured) = 268 mg/L

EC50 (Pimephales promelas; 96 h; flow through; arithmetic mean measured; loss of equilibrium) = 268 mg/L

Description of key information

LC50 (96 h; Lepomis macrochirus, fresh water; static; nominal) = 32 mg/L (publication, equivalent to OECD 203; RL2);

LC50 (96 h; Menidia beryllina, marine water; static; nominal) = 24 mg/L (publication, equivalent to OECD 203; RL2)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

32 mg/L

Marine water fish

Marine water fish

Effect concentration:

24 mg/L

Additional information

Key study:

Toxicity of n-butylamine to freshwater fish and coastal fish (marine/salt water) fish was assessed in a published study (key study) testing 47 industrial chemicals for fish toxicity (Dawson et al., 1975). The study was performed equivalent to OECD 203 with acceptable restrictions (RL2). The tested freshwater species was Bluegill (Lepomis macrochirus), and at least 10 fish were tested per concentration (4 test item concentrations (nominal) applied: 10, 32, 50, and 79 mg/L). The tested salt water species was Tidewater Silverside (Menidia beryllina), and at least 20 fish were tested per concentration (5 test item concentrations (nominal) applied: 10, 18, 32, 50, and 100 mg/L). No analytical conformation of test item concentrations was performed. However, based on the very high water solubility of the compound (miscible with water), the very low adsorption potential (experimentally determined Koc from batch-equilibrium test: ca.49 L/kg) and being not volatile (fully ionized at environmental pH) it may be assumed with high confidence that the test item was stable during the test.

While not all validity criteria specified in OECD 203 could be assessed directly, taking all information given into account it is very probable that all validity criteria were met. While pH was measured, it was not reported. Thus, based on a pKa of 10.8 (for alkaline functional group) and unbuffered test medium, alkaline pH could have contributed or even have been causative for observed toxicity. The derived LC50 values may therefore be regarded as conservative.

Results:

A) Fresh water: only at the lowest test item concentration applied (10 mg/L), no mortality was observed during the 96 h of the test. At 32, 50, and 79 mg/L 50%, 80%, and 90 % mortality was observed, respectively, after 96 hours. The LC50 (96 h) for freshwater fish was identified as 32 mg/L.

B) Marine water: only at the lowest test item concentration applied (10 mg/L), no mortality was observed during the 96 h of the test. At 18, 32, 50, and 100 mg/L 35%, 67%, 100% and 100 % mortality was observed, respectively, after 96 hours. The LC50 (96 h) for salt water/marine fish was identified as 24 mg/L.

Supporting data are available:

In a fully reliable study (RL 1; Geiger et al., 1985; published 1986), acute fish toxicity of n-butylamine was determined using freshwater fish Pimephales promelas (Fathead Minnow) in a flow-through design (14 exchanges per day) with daily measurements of test item concentrations (incl. day zero). Arithmetic mean measured values (n= 5) for the five nominal concentrations were between 74% and 88% of nominal, and above 80% for all but the second highest concentration applied. Effect concentrations were determined based on arithmetic mean measured concentrations. Besides mortality, effects on behaviour and appearance were observed after 4, 24, 48, 72, and 96 hr.

The tested compound n-butylamine is a strong base (pKa 10.8), such that after preparation the stock solution was neutralized to the average pH of the testing water (Lake Superior water, filtered before use and analysed for range of critical parameters) using concentrated HCl. The measured pH during testing was on average 7.55 (SD 0.08).

All validity criteria of OECD 203 (1992) were fulfilled.

Results:

Observed non-lethal effects were loss of schooling behaviour, swimming near surface, hyperactivity, increased respiration, and loss of equilibrium prior to death.

LC50 (Pimephales promelas; 96 h; flow through; arithmetic mean measured) = 268 mg/L

EC50 (Pimephales promelas; 96 h; flow through; arithmetic mean measured; loss of equilibrium) = 268 mg/L

Overall conclusion:

Given the reliable data from Lake Superior studies (Geiger et al., 1985; published 1986), it is highly probable that alkaline pH is contributing considerably to fish toxicity and responsible for LC50 -values form Dawson et al. (1975) being lower by approximately a factor of 8 (fresh water) to 11 (marine water). However, no direct comparison for the same species is available, and pH values are not reported by Dawson et al. (1975). Further, no other reliable toxicity data for salt water / marine fish species are available other than those by Dawson et al. (1975). Therefore, as a conservative approach the data from Dawson et al. are used as a basis for classification and labelling as well as environmental hazard and risk assessment.