Cyanuric acid

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study not performed to GLP or guideline but is well reported

Qualifier:

according to guideline

Guideline:

other: EPA/600/4-90/027.

GLP compliance:

no

Test organisms (species):

Menidia beryllina

Details on test organisms:

TEST ORGANISM
- Common name: Inland Silversides
- Source: Obtained from a commercial supplier
- Age at study initiation: 11 days


ACCLIMATION
- Acclimation period: Held and acclimated for 1 day in the test dilution water
- Health during acclimation (any mortality observed): Less than 5% mortality occurred

Test type:

static

Limit test:

no

Total exposure duration:

96 h

Hardness:

522 - 1560 as CaCO3 (mg/l)

Test temperature:

24.4-25.3ºC

pH:

6.91-8.09

Dissolved oxygen:

7.6-8.3 mg/L

Nominal and measured concentrations:

500, 1000, 2000, 4000 and 8000 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: 250 mL glass beaker
- Material, size, headspace, fill volume: 250 ml glass beakers
-Aeration: Aerated and aged for more than 24 h prior to using in the test
- No. of organisms per vessel: 10 organisms
- No. of vessels per concentration (replicates): 2


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Synthetic seawater prepared by addition of reagent-grade marine salt to Millipore water


OTHER TEST CONDITIONS
- Photoperiod: 16 h light and 8 h dark



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Daily - test organisms with abnormal behaviour and signs of stress, and dead test organisms

Reference substance (positive control):

yes

Remarks:

Potassium chloride

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

8 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

4 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

8 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No mortalities were observed at the highest concentration tested.

Reported statistics and error estimates:

LC50s were calculated via the Spearman-Karber method; LOEC and NOECs were analyzed using Fisher’s exact test.

Validity criteria fulfilled:

yes

Conclusions:

96 h LC50 > 8000 mg/L which was the highest concentration tested.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The acute toxicity of cyanuric acid to bluegill sunfish was assessed using the methods outlined by the Committee on Methods for Acute Toxicity Tests with Aquatic Organisms.

GLP compliance:

no

Analytical monitoring:

no

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: Bluegill sunfish
- Source: Osage Catfisheries Inc., Osage Beach, Missouri, USA.
- Length at study initiation: 27.8 mm
- Weight at study initiation: Mean weight: 0.51 g

ACCLIMATION
- Acclimation period: 48 h
- Type and amount of food: Rangen’s commercial fish food
- Feeding frequency: Daily until 48 h prior to testing at which time feeding was discontinued.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

220 mg/l as CaCO3

Test temperature:

24h: 22°C
48h: 22°C
72h: 22°C

pH:

24h: 8.0
48h: 8.0
72h: 8.1

Dissolved oxygen:

24h: 7.3 mg/l
48h: 5.2 mg/l
72h: 4.0 mg/l

Nominal and measured concentrations:

1000 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type open
- Material, size, headspace, fill volume: 5 gallon glass vessels filled with 15 L of well water
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 1.5 l/animal


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory well water
- Alkalinity: 210 mg/l as CaCO3
- Intervals of water quality measurement: 24 h


OTHER TEST CONDITIONS
- Photoperiod: 16 h daylight photoperiod


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: A preliminary range finding test indicated that the toxicity of cyanuric acid exceeded 1000 mg/l
- Results used to determine the conditions for the definitive study: Following the range finding test it was decided to conduct the definitive test with a test concentration of 1000 mg/l

Reference substance (positive control):

yes

Remarks:

Antimycin A

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No adverse effects noted
- Mortality of control: No mortalities

Results with reference substance (positive control):

- LC50:
24 h LC50 (95 % C.I.) = 0.00012 mg/l (0.000096 – 0.00015 mg/l)
48 h LC50 (95 % C.I.) = 0.000096 mg/l (0.000079 – 0.00012 mg/l)
96 h LC50 (95 % C.I.) = 0.000084 mg/l (0.000067 – 0.00010 mg/l)

Reported statistics and error estimates:

LC50 values were calculated using the technique of Litchfield J.T. and Wilcoxon F (1949)

Validity criteria fulfilled:

no

Remarks:

Dissolved oxygen concentration reached below 60% saturation, validity criteria states that the concentration should remain>60% for the duration of the study

Conclusions:

96 h LC50 > 1000 mg/L. Cyanuric acid is not harmful to bluegill sunfish

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The acute toxicity of cyanuric acid to rainbow trout was assessed using the methods outlined by the Committee on Methods for Acute Toxicity Tests with Aquatic Organisms.

GLP compliance:

no

Analytical monitoring:

no

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Beitey’s Resort, Valley, Washington, USA
- Length at study initiation (mean): 43.9 mm
- Weight at study initiation (mean): 1.07 g


ACCLIMATION
- Acclimation period: The fish were acclimated and held without food for 48 h prior to testing
- Type and amount of food: Rangen’s commercial fish food

Test type:

static

Limit test:

no

Total exposure duration:

96 h

Hardness:

220 mg/l as CaCO3

Test temperature:

See table 1

pH:

See table 2

Dissolved oxygen:

See table 3

Nominal and measured concentrations:

210, 370, 650, 1200 and 2100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: 5 gallon glass vessels containing 15 L of laboratory well water
- Type: open
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 1.5 l/animal




OTHER TEST CONDITIONS
- Photoperiod:16 h daylight photoperiod


EFFECT PARAMETERS MEASURED: Mortality was observed at 24, 48, 72 and 96 hours


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: A previous bioassay with bluegill sunfish indicated that the toxicity of cyanuric acid exceeded 1000 mg/l

Reference substance (positive control):

yes

Remarks:

Antimycin A

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 2 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No mortalities or adverse effects were observed.

Results with reference substance (positive control):

LC50:
24 h LC50 (95 % C.I.) = 0.00022 mg/l (0.00018 – 0.00026 mg/L)
48 h LC50 (95 % C.I.) = 0.000098 mg/l (0.000078 – 0.00012 mg/L)
96 h LC50 (95 % C.I.) = 0.000066 mg/l (0.000056 – 0.000078 mg/l)

Reported statistics and error estimates:

LC50 values were calculated using the technique of Litchfield J.T. and Wilcoxon F (1949)

Sublethal observations / clinical signs:

Table 1: Test temperatures (°C):

Concentration (mg/L)	Observation period (h)
	24	48	96
Control	12.0	12.5	12.0
210	12.0	12.5	12.0
2100	12.0	12.5	12.0

Table 2: pH values

Concentration (mg/l)	Observation period (h)
	24	48	96
Control	7.8	7.8	7.8
210	7.8	7.9	7.8
2100	7.9	7.9	7.8

Table 3: Dissolved oxygen (mg/l)

Concentration (mg/l)	Observation period (h)
	24	48	96
Control	7.6	7.1	6.2
210	7.6	7.0	6.1
2100	7.1	7.0	6.0

Conclusions:

Based on the 96 h LC50 value of >2100 mg/L, cyanuric acid is not harmful to rainbow trout.

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The acute toxicity of cyanuric acid to fathead minnows was assessed using the methods outlined by the Committee on Methods for Acute Toxicity Tests with Aquatic Organisms.

GLP compliance:

no

Analytical monitoring:

no

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Source: Fattig Fish Hatchery, Brady, Nebraska, USA
- Length at study initiation (mean): 20.9 mm
- Weight at study initiation (mean): 0.17 g
- Feeding during test: No feeding discontinued 48 h before test

Test type:

static

Limit test:

no

Total exposure duration:

96 h

Hardness:

220 mg/L as CaCO3

Test temperature:

See table 1

pH:

See table 2

Dissolved oxygen:

See table 3

Nominal and measured concentrations:

210, 370, 650, 1200 and 2100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 5 gallon glass vessels contaiing 15 L water
- No. of organisms per vessel: 10 animals/vessel
- No. of vessels per concentration (replicates): 1 vessel/concentration
- Biomass loading rate: 1.5 l/animal


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory well water


OTHER TEST CONDITIONS
- Photoperiod: 16 h daylight photoperiod


EFFECT PARAMETERS MEASURED: Mortality, observations made at 24, 48, 72 and 96 h


TEST CONCENTRATIONS
- Test concentrations: A previous bioassay with fathead minnow- indicated that the toxicity of cyanuric acid exceeded 1000 mg/l

Reference substance (positive control):

yes

Remarks:

Antimycin A

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 2 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Results with reference substance (positive control):

- LC50:
24 h LC50 (95 % C.I.) = 0.000070 mg/l (0.000060 – 0.000082 mg/l)
48 h LC50 (95 % C.I.) = 0.000048 mg/l (0.000040 – 0.000057 mg/l)
96 h LC50 (95 % C.I.) = 0.000044 mg/l (0.000038 – 0.000052 mg/l)

Reported statistics and error estimates:

LC50 values were calculated using the technique of Litchfield J.T. and Wilcoxon F (1949)

Sublethal observations / clinical signs:

Table 1: Test temperatures ( °C)

Concentration (mg/l)	Observation period (h)
	24	48	96
Control	22.0	22.0	22.0
210	22.0	22.0	22.0
2100	22.0	22.0	22.0

Table 2: pH values

Concentration (mg/l)	Observation period (h)
	24	48	96
Control	7.8	7.8	7.8
210	7.8	7.8	7.8
2100	7.9	7.8	7.8

Table 3: Dissolved oxygen (mg/l)

Concentration (mg/l)	Observation period (h)
	24	48	96
Control	7.6	6.4	5.9
210	7.6	6.6	6.0
2100	7.3	6.3	5.8

Conclusions:

Based on the 96 h LC50 value of >2100 mg/L, cyanuric acid is not harmful to fathead minnows.

Description of key information

96 h static acute toxicity studies with cyanuric acid were performed with rainbow  trout, bluegill sunfish and fathead minnows (freshwater species) and inland silversides (marine species).  

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1 000 mg/L

Marine water fish

Marine water fish

Effect concentration:

8 000 mg/L

Additional information

Acute fish studies were performed with the freshwater species bluegill sunfish, rainbow trout and fathead minnow. Bluegill sunfish were exposed to a nominal concentration of 1000 mg/L cyanuric acid for 96 h. The LC50 was > 1000 mg/L. No mortalities or adverse effects were observed. Rainbow trout and fathead minnow were exposed to nominal concentrations of 210, 370, 650, 1200 and 2100 mg/L cyanuric acid for 96 h. No mortalities were observed and the LC50 was determined to be > 2100 mg/L for both species.

The lowest LC50 derived from the three aquatic studies on freshwater fish was > 1000 mg/L based on nominal concentrations.

An acute fish study was performed with one saltwater species, inland silver sides. Fish were exposed to nominal concentrations of 500, 1000, 2000, 4000 and 8000 mg/L cyanuric acid. No mortalities occurred at the highest concentration tested. The LC50 was determined to be > 8000 mg/L.