Nonanoic acid

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:

Test performed on 18 May 1982.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (e.g. non-GLP, no detailed information given on measurement of test parameters like pH, dissolved oxygen)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

pH and dissolved oxygen measured less frequently than required by guideline

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all chambers at time 0 h, 24 h, 48 h, 72 h, and 96 h
- Sampling method: sampled at mid-depth of exposure chamber
- Sample storage conditions before analysis: samples analysed immediately or adequately preserved for later analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: stock toxicant = 1000 mg/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): none

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnow
- Strain: brood stock provided by the US EPA Environmental Research Laboratory-Duluth
- Source: laboratory culture
- Age at study initiation (mean and range, SD): 33 d
- Length at end of exposure (length definition, mean, range and SD): 21.9 ± 2.079 mm
- Weight at end of exposure (mean and range, SD): 176 ± 48.4 mg
- Feeding during test: none


ACCLIMATION
- Acclimation period: none, fish were kept at conditions similar to test
- Type and amount of food: freshly hatched brine shrimp nauplii to excess
- Feeding frequency: 3 times/d; 2 times/d on weekends
- Health during acclimation (any mortality observed): only groups of fish having healthy appearance and no history of unusual thermal history or abnormally high mortality rate were used

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

47.0 mg/L as CaCO3

Test temperature:

25.3 ± 0.38 °C

pH:

7.46 ± 0.02

Dissolved oxygen:

6.0 ± 0.59 mg/L

Nominal and measured concentrations:

nominal (mg/L): 0 (control), 25.3, 38.9, 59.9, 92.1, 142
measured (corrected average; mg/L): < 2, 20.6, 28.2, 49.0, 80.2, 120
recovery: 110 ± 7 %

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass tanks, 1.0 L
- Aeration: no information
- Type of flow-through (e.g. peristaltic or proportional diluter): proportional diluter
- Renewal rate of test solution (frequency/flow rate): 36 v/d
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: 3.344 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: natural water from Lake Superior (data from 1972) or (for few tests) dechlorinated water from City of Superior (WI)
- Total organic carbon: no data
- Particulate matter: < 1 mg/L / no data
- Metals (µg/L):
- Al: 1-26 / 0.60-1.9
- Cd: < 0.1 / < 0.1
- Cr: 2-20 / < 0.1
- Co: < 0.5 / < 0.5
- Cu: 0.3-3.2/ 2.0-6.0
- Fe: 2-83 / 160-194
- Pb: 7-20 / < 0.1
- Mn: 0.2-11.5 / 6.6-7.8
- Ni: < 0.5 / < 1.0-1.3
- Zn: 1.0-2.7 / 2.2-3.0
- Pesticides: no data
- Chloride: 1.2-1.3 mg/L / 3.6-4.1 mg/L
- Alkalinity: 43.0 mg/L as CaCO3 (for test date 18 Mar 1982)
- Ca/Mg ratio: ca. 6.5:1
- Conductivity: 78-86 µmhos/cm / 91-138 µmhos/cm
- Culture medium different from test medium:
- Intervals of water quality measurement:


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h daily photoperiod
- Light intensity: no data


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- visible abnormalities and mortality: after 0, 1, 3, 6, 24, 48, 72, and 96 h
- pH: at least once in control, low medium and high test concentration
- dissolved oxygen: after 0, 24, and 96 h in control, low medium and high test concentration
- temperature: daily
- analytical quantification of test concentrations: all chambers after 0, 24, 48, 72, and 96 h
TEST CONCENTRATIONS
- Spacing factor for test concentrations: ca. 1.5
- Justification for using less concentrations than requested by guideline: not applicable
- Range finding study
- Test concentrations: no data
- Results used to determine the conditions for the definitive study: no data

Reference substance (positive control):

not required

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

104 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL: 93.4-115 mg/L

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

104 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

behaviour

Remarks on result:

other: 95 % CL: 93.4-115 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

25.3 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: affected fish became hypoactive, resting on the tank bottom prior to death
- Observations on body length and weight: determined only after exposure
- Other biological observations: none
- Mortality of control: 0 %
- Other adverse effects control: no
- Abnormal responses: no
- 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:

Estimation of the LC50 and EC50 was made using the trimmed Spearman-Kärber method (Hamilton et al., 1977).

Sublethal observations / clinical signs:

Nominal test concentrations (mg/L)	Cumulative mortality (n) after exposure (h)
	0	1	3	6	12	24	48	72	96
0	0	0	0	0	0	0	0	0	0
25.3	0	0	0	0	0	0	0	0	0
38.9	0	0	0	0	0	1	1	2	2
59.9	0	0	0	0	0	2	2	3	3
92.1	0	0	0	0	0	1	1	3	3
142	0	0	0	6	6	13	14	14	14

Nominal test concentrations (mg/L)	Affected fish (n) after exposure (h)
	0	1	3	6	12	24	48	72	96
0	0	0	0	0	0	0	0	0	0
25.3	0	0	0	0	0	0	0	0	0
38.9	0	0	0	0	0	1	1	2	2
59.9	0	0	0	0	0	2	2	3	3
92.1	0	0	0	0	0	2	1	3	3
142	0	1	8	7	6	14	14	14	14

Validity criteria fulfilled:

yes

Remarks:

Based on current guidelines like OECD TG 203

Conclusions:

Based on mean measured concentrations, the LC50 (96 h) for fish (Pimephales promelas) is 104 mg/L.

Executive summary:

Nonanoic acid was tested on fathead minnows (Pimephales promelas) in a 96-h flow-through acute toxicity study. No specific guideline was reported, but documentation is sufficient to assign validity and good reliability. The test design is similar to OECD 203. Five test concentration and 1 control were set up. One test chamber with 20 fish was used per test concentration. The test concentrations were analytically verified by GLC every day in each test chamber (recovery: 110 ± 7 %).

Concentrations were as follows:

nominal (mg/L): 0 (control), 25.3, 38.9, 59.9, 92.1, 142

measured (corrected average; mg/L): < 2, 20.6, 28.2, 49.0, 80.2, 120

No mortalities and signs of abnormal behaviour were observed in the control and the lowest tested concenctration (nominal: 25.3 mg/L) . After 6 h, the first mortalities occurred at highest concentration (nominal: 142 mg/L). Based on mean measured concentrations, the 96-h LC50 was 104 mg/L (95% CL: 93.4 -115 mg/L).

Description of key information

Fathead minnow (P. promelas): 96-h LC50 = 104 mg/L (similar to OECD TG 203, flow-through, measured; Brooke et al., 1984)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

104 mg/L

Additional information

Nonanoic acid was tested on fathead minnows (Pimephales promelas) in a 96-h flow-through acute toxicity study similar to OECD 203. Based on mean measured concentrations, the 96-h LC50 was 104 mg/L (95% CL: 93.4 -115 mg/L).

The available and reliable information indicates that acute toxicity to fish is above 100 mg/L (Brooke et al., 1984). Hence, nonanoic acid can be regarded as acutely not toxic to fish.

 

There are two other reliable studies available, which confirm that the 96-h LC50 is around 100 mg/L (OPP, 2000). The study from Brooke et al. (1984) was selected as key study due to the detailed documentation and the analytical verification of test item concentrations.

Supporting study results:

Oncorhynchus mykiss: 96-h LC50 = 96 mg/L (static; OPP, 2000)

Lepomis macrochirus: 96-h LC50 > 105 mg/L (static; OPP, 2000)