4-(cyclohexylamino)butane-1-sulfonic 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:

02-Aug-2019 - 29-Oct-2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Correction factor for purity: not required
- Stability at higher temperatures: stable
- Solubility in water: 110 g/L

Analytical monitoring:

yes

Details on sampling:

During the test, samples for possible analysis were taken from all test concentrations and the control.
Frequency: at t=0 h, t=24 h and t=96 h
Volume: 2.0 mL
Storage: Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.
Additionally, reserve samples of 2.0 mL were taken from all test solutions for possible analysis. If not already used, these samples were stored in a freezer (≤-15°C) for a maximum
of three months after delivery of the draft report, pending the decision of the sponsor for additional analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Preparation of test solutions started with the highest concentration of 100 mg/L applying a one-hour period of magnetic stirring to accelerate the dissolution of the test item in test
medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium.
- Other relevant information: All test solutions were clear and colorless at the end of the preparation procedure.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Carp (Cyprinus carpio, Teleostei, Cyprinidae) Linnaeus, 1758.
- Source: De Haar Vissen’, Zodiac proefacc., Wageningen University and Research Centre, The Netherlands.
- Length at study initiation: 2.8 ± 0.4 cm.
- Weight at study initiation: 0.23 ± 0.12 g.
- Characteristics: F1 from a single parent-pair bred in UV-treated water.
- Total fish used: 20.

HOLDING
- Quarantine/Acclimatisation: At least 12 days after delivery.
- Medium: Test Medium (see Deteail on test conditions for the composition of the test medium).
- Feeding: Daily with pelleted fish food (Essence 0.5-0.8 mm, Coppens International B.V., Helmond, The Netherlands).
- Validity of batch: In the batch of fish used for the test, mortality during the seven days prior to the start of the test was less than 5%.

FEEDING DURING THE TEST
No feeding during the test period.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

180 mg/L expressed as CaCO3.

Test temperature:

21°C

pH:

7.7 - 8.0

Dissolved oxygen:

7.0 - 9.2

Salinity:

Not applicable

Conductivity:

Not applicable

Nominal and measured concentrations:

Nominal concetrations: 1.0, 10 and 100 mg/L and a control.
Measured concentrations: The measured concentrations were at 92 and 96% relative to the nominal concentrations at the start and end of the test, respectively. Based on these results, effect parameters were expressed as analytically confirmed nominal concentrations. See Table 2 in 'Any other information on results incl. tables' for details.

Details on test conditions:

TEST SYSTEM
- Test vessel: Control and highest concentration: 10 litres, containing 8.0 litres of test solution. Intermediate concentrations: 3.5 litres, containing 3.0 litres of test solution.
- Test type: Static.
- Aeration: no aeration.
- Number of fish: Control and highest concentration: 7 per test group. Intermediate concentrations: 3 per test group.
- Biomass loading rate: Control and highest concentration: 0.20 g fish/litre, i.e. 7 fish per 8 litres of test medium. Intermediate concentrations: 0.23 g fish/litre, i.e. 3 fish per 3 litres of test medium.

TEST MEDIUM / WATER PARAMETERS
- Test medium: The following salts (analytical grade) were added to tap water Waterbehandeling, Berkel-Enschot, The Netherlands):
CaCl2.2H2O: 211.5 mg/L
MgSO4.7H2O: 88.8 mg/L
NaHCO3: 46.7 mg/L
KCl: 4.2 mg/L
The hardness of test medium expressed as CaCO3: 180 mg/L.
- Culture medium different from test medium: no
- Intervals of water quality measurement: Dissolved oxygen content, pH and temperature were measured daily in all vessels, beginning at the start of the test (day 0).

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily with a light intensity in the range of 501 to 837 lux.
- Feeding: No feeding from 24 hours prior to the test and during the total test period.
- Introduction of fish: Within 20 minutes after preparation of the test media from a holding tank with comparable water quality parameters and pH and temperature differences between test and holding tank media of less than 1.0 unit and 1.0°C, respectively.

EFFECT PARAMETERS MEASURED
- Mortality and other effects: At 2.5, 24, 48, 72 and 96 hours following the start of exposure. In addition, every afternoon from day 0 to observe for any dead or severely distressed fish. Dead fish were removed when observed.

TEST CONCENTRATIONS
- Combined Limit/Range-finding study test concentrations: 1.0, 10 and 100 mg/L.

TERMINAL PROCEDURES
At the end of the test the surviving fish were rapidly killed by exposing them to ca. 1.2% ethylene glycol monophenylether in water.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No mortality or other effects were observed in the control or at any of the concentrations tested, see Table 1 in 'Any other information on results incl. tables'.

Reported statistics and error estimates:

No LC50 could be calculated because the test item proved to be non-toxic (LC50 > maximum concentration).

Sublethal observations / clinical signs:

Table 1: Incidence of Mortality and Total Mortality in the Test

4-(cyclohexylamino)butane-1-sulfonic acid Nominal conc. (mg/L)	Initial  Number of fish	Cumulativemortality					Total Mortality (%)
		2.5h	24h	48h	72h	96h
Control	7	0	0	0	0	0	0
1.0	3	0	0	0	0	0	0
10	3	0	0	0	0	0	0
100	7	0	0	0	0	0	0

 

Table 2: Analytical results 

Time of sampling (h)	Nominal concentration (mg/L)	Analyzed concentration (mg/L)	Relative to nominal (%)	Relative to initial (%)
0	0	n.d.	n.a.	-
	100	92.2	92	-
24	0	n.d.	n.a.	n.a.
	100	97.6	98	106
96	0	n.d.	n.a.	n.a.
	100	96.5	96	105

n.d.: Not detected; n.a.: Not applicable

Validity criteria fulfilled:

yes

Remarks:

See 'overall remarks' for details on validity criteria

Conclusions:

In conclusion, the 96h-LC50 for carp (Cyprinus carpio) exposed to 4 (cyclohexylamino)butane-1-sulfonic acid was beyond the range of concentrations tested, i.e. exceeded the analytically confirmed concentration of 100 mg/L.

Executive summary:

In a 96-h acute toxicity study conducted according to the OECD guideline 203 and GLP principles, the acute toxicity of 4-(cyclohexylamino)butane-1-sulfonic acid to carp (Cyprinus carpio) was investigated.

In an static combined limit/range-finding test, carp were exposed to an untreated control and to 1.0, 10 and 100 mg/L (control and 100 mg/L 7 fish per treatment and intermediate concentrations 3 fish per treatment). The measured concentrations of the highest tested concentration were at 92 and 96% relative to the nominal concentrations at the start and end of the test, respectively. Based on these results, effect parameters were expressed as analytically confirmed nominal concentrations. No mortality or other effects were observed in the control or at any of the concentrations tested.

In conclusion, the 96h-LC₅₀ value for carp (Cyprinus carpio) exposed to 4-(cyclohexylamino)butane-1-sulfonic acid was beyond the range of concentrations tested, i.e. exceeded the concentration of 100 mg/L.

The test met all validity criteria and is considered to be reliable without restriction.

Description of key information

The 96h-LC₅₀ value for carp (Cyprinus carpio) exposed to 4-(cyclohexylamino)butane-1-sulfonic acid was beyond the range of concentrations tested, i.e. exceeded the analytically confirmed concentration of 100 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

> 100 mg/L

Additional information

In a 96-h acute toxicity study conducted according to the OECD guideline 203 and GLP principles, the acute toxicity of 4-(cyclohexylamino)butane-1-sulfonic acid to carp (Cyprinus carpio) was investigated.

In an static combined limit/range-finding test, carp were exposed to an untreated control and to 1.0, 10 and 100 mg/L (control and 100 mg/L 7 fish per treatment and intermediate concentrations 3 fish per treatment). The measured concentrations of the highest tested concentration were at 92 and 96% relative to the nominal concentrations at the start and end of the test, respectively. Based on these results, effect parameters were expressed as analytically confirmed nominal concentrations. No mortality or other effects were observed in the control or at any of the concentrations tested.

In conclusion, the 96h-LC₅₀ value for carp (Cyprinus carpio) exposed to 4-(cyclohexylamino)butane-1-sulfonic acid was beyond the range of concentrations tested, i.e. exceeded the concentration of 100 mg/L.

The test met all validity criteria and is considered to be reliable without restriction.