Cyanoguanidine

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

adult fish: sub(lethal) effects

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 1997 - February 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Sampling time: on exposure days 0, 7, and 14
- Sampling method: test solution was collected from the middle layer of a test vessel and analyzed using HPLC

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- the required amount of test solution was dissolved in dilution water to prepare 10000 mg/l of undiluted test solution
- the test solutions were prepared by mixing undiluted test solution and dilution water at a fixed flow rate (undiluted test solution: 2.5 ml/min, dilution water 22.5 ml/min); the flow volume of test solution was adjusted with a constant rate pump, and the flow volume of dilution water with a flow volume adjustment cock and capillary tube

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: Himedaka
- Source: Nakajima Yogyojo (Daimyojin, Nagas-machi, Tamana-gun, Kumamoto JAPAN 869-0123
- Length at study initiation (mean and range): 2.0 cm (1.9- 2.1 cm)
- Weight at study initiation (mean and range): 0.12 g (0.10 - 0.15 g)
- Feeding during test
- Food type: TetraMin
- Amount: provided at 2 % of the daily fish weight
- Frequency: daily


ACCLIMATION
- Acclimation period: > 12 days in conditions (water quality, temperature etc.) equivalent to those used in the test
- Acclimation conditions: same as test
- Type and amount of food: TetraMin
- Feeding frequency: feeding was stopped 24 hours before study initiation
- Health during acclimation (any mortality observed): Mortality was < 5 % during the 7-day period before the start of exposure

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

14 d

Post exposure observation period:

No post exposure observation period

Hardness:

40.5 mg/l as CaCO3

Test temperature:

24.1 - 24.5 °C

pH:

7.1 - 7.7

Dissolved oxygen:

7.5 - 8.2 mg/l

Salinity:

not applicable

Nominal and measured concentrations:

From the results of a 96-hour acute toxicity test with fish (LC50 > 100 mg/l), the maximum test concentration was set as 100 mg/l, and five concentration groups were set with a common ratio of 2 (100, 50, 25, 12.5, 6.25 mg/l; nominal concentration). A control group was set up using just dilution water.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Fill volume: 1.8 L
- Aeration: no
- Type of flow-through: constant rate pump (Glass microvolume constant rate pump GMW-A, Tokyo Rikakikai CO. Ltd.)
- Renewal rate of test solution (frequency/flow rate): 25.0 ml/min; approx. 20 water changes per day
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water
- Metals: < L.O.D., except Iron: 0.03 mg/l
- Pesticides: < L.O.D.
- Chlorine: < 0.02 mg/l
- Alkalinity: 29.0 mg/l
- Ca/mg ratio: 2.95
- Conductivity: 148 µS/cm
- Culture medium different from test medium: no


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: light / dark = 16 hours / 8 hours
- Light intensity: room light
- Test water temperature: 24 +/- 1 °C


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

yes

Remarks:

CuSO4: LC50 (96 hours) = 0.930 mg/l

Duration:

14 d

Dose descriptor:

other: LLC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: The results of investigation of significant difference in survivor weight, mortality rate in test organisms and observed symptoms were included in assessment of NOEC.

Duration:

7 d

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- During the test general symptoms and specific symptoms (spinal curvature, bleeding, body color change, mucus secretion, etc.) were recorded, as was the number of dead organisms, on a daily basis
- Symptoms of toxicity and/or decrease in feeding were not observed in any concentration group or the control group.
- Weight of surviving test organisms at the end of exposure: no significant differences were found between the weight of the surviving Oryzias latipes to cyanoguanidine for 14 days in any of the concentration groups and that of the control group

Results with reference substance (positive control):

CuSO4: LC50 (96 hours) = 0.930 mg/l

Reported statistics and error estimates:

- NOEC: the weight of survivors at the end of exposure was tested for homogeneity of variance using the Bartlett method, and then the one-factor ANOVA and Dunnett Multiple Comparison methods were employed to check for significant differences between the control group and the various concentration groups

Validity criteria fulfilled:

yes

Conclusions:

Based on the results in this test the LLC, LOEC and LC50 for Diycandimaide were > 100 mg/l. The NOEC was ≥ 100 mg/l.
Therefore, Dicyandiamide is not classified as toxic towards fish.

Executive summary:

The 14-day prolonged toxicity of Dicyandiamide to adults of Killifish (Oryzias latipes) was studied under flow through conditions according to OECD Guideline 204.  Animals were exposed control and test chemical nominal concentrations of 0, 6.25, 12.5, 25, 50, and 100 mg/l.

The test system was maintained at 24.1 - 24.5 °C and a pH of 7.1 - 7.7.

The 14-day LLC and NOEC values, based on mortality, were both > 100 mg/l.

This toxicity study is classified as acceptable and satisfies the guideline requirement for 14-day prolonged toxicity study with fish.

 

Results Synopsis

 

Test Organism mean wet weight: 0.12 g

Test Organism mean length: 2.0 cm

Test Type: Flow-through

 

LLC:             > 100 mg/l

LOEC:          > 100 mg/l

NOEC:          ≥ 100 mg/l

LC₅₀:            > 100 mg/l

 

Description of key information

The 14-day prolonged toxicity of Dicyandiamide to adults of Killifish (Oryzias latipes) was studied under flow through conditions according to OECD Guideline 204.  Animals were exposed control and test chemical nominal concentrations of 0, 6.25, 12.5, 25, 50,

and 100 mg/l. The test system was maintained at 24.1 - 24.5 °C and a pH of 7.1 - 7.7.
 The 14-day LLC and NOEC values, based on mortality, were both > 100 mg/l.

Additional information

The 14-day LLC and NOEC values, based on mortality, were both > 100 mg/l.

 

Results Synopsis

Test Organism mean wet weight: 0.12 g

Test Organism mean length: 2.0 cm

Test Type: Flow-through