Potassium nitrite

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:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed according to the guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Test chemical concentrations used for the study were 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l,respectively.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebra Fish
- Source: Anytime Pet
- Length at study initiation (length definition, mean, range and SD): average 1.4 cm
- Weight at study initiation (mean and range, SD): average 0.045 g
- Housing:The fishes were kept in a static tank in tap water passed through reverse osmosis system, under natural conditions along with proper feed and aeration.
- Duration of housing: 15 days
- Photoperiod: 16 hours light and 8 hours dark
- Diet : Standard brand feed, once daily
- Acclimatization: seven days
- Feeding frequency: Once in a day

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

155.5 mg of CaCO3

Test temperature:

23.9°C

pH:

7.2

Dissolved oxygen:

7.6 mg/l

Nominal and measured concentrations:

Nominal concentrations: 0, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, respectively.

Details on test conditions:

TEST SYSTEM
- Test vessel: Aquaria
- Material, size, headspace, fill volume: 5 liters of plastic aquaria filled with 2 liter of water
- Aeration: Aeration in test vessels was provided 1 day before the start of experiment
- No. of organisms per vessel: 8 fishes

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

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)

Sublethal observations / clinical signs:

Table 1. Mortality and symptoms:

Nominal Concentration (mg/l)	Number of fish		Mortality (cumulated) after
			3h		6h		24h		48h		72h		96h
			V1	V2	V1	V2	V1	V2	V1	V2	V1	V2	V1	V2
Control	4	4	-	-	-	-	-	-	-	-	-	-	-	-
6.25	4	4	-	-	-	-	-	-	-	-	-	-	-	-
12.5	4	4	-	-	-	-	-	-	-	-	-	-	-	-
25	4	4	-	-	-	-	-	-	-	-	-	-	-	-
50	4	4	-	-	-	-	-	-	-	-	-	-	-	-
100	4	4	-	-	-	-	-	-	-	-	2	2	2	2

Visible Symptoms:

Nominal Concentration (mg/l)

Number of fish

symptom (cumulated) after

3h

6h

24h

48h

72h

96h

V1

V2

V1

V2

V1

V2

V1

V2

V1

V2

V1

V2

Control

4

4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

6.25

4

4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

12.5

4

4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

25

4

4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

50

4

4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

100

4

4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS4

NS2

NS2

NS2

NS2

Explanation of symptoms:

A: apathy

N: Narcotic-like state

C: Swimming near water surface

M: Slow movements compared to control

NS: No abnormal symptoms

S: Surfacing behaviour

L: Loss of equilibrium

SM: Shimming movement

H1: Hyperactivity

H2: Hypo activity

B: Bending behavior

F: Fin rot

IS: Invert Swimming

SB: Swimming behaviour

RF: Respiratory Function

P: Pigmentation

Validity criteria fulfilled:

yes

Conclusions:

Based on the effect of test chemical on mortality of the test organism, the median lethal concentration (LC50 (96 h)) was determined to be ≥100 mg/l.

Executive summary:

Short term toxicity to fish was conducted for 96 hrs for assessing the effect of test chemical. The test was performed in accordance to OECD guideline No. 203 “Fish Acute Toxicity Test”. Zebra fish (Danio rerio) of average weight 0.045 g and average length of 1.4 cm was used as a test organism for the study. Test fishes were kept in a static tank in tap water passed through reverse osmosis system, under natural conditions along with proper feed and aeration. During the housing period, test fishes were fed once daily with standard brand fed. The test conditions during the housing of the test organisms were oxygen content of 7.6 mg/l, pH 7.5, water temperature 23.9°C and under a photoperiod of 16:8 hr light: dark conditions, respectively. Test was performed using test chemical concentrations of 0, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, respectively. Total 8 fishes were exposed to test chemical in a 5 lit bowl aquaria containing 4 liters of potable water. The test vessels were placed in a room at a temperature of 23.9°C, pH 7.2, hardness of water 155.5 mg of CaCO3 and under a photoperiod of 16:8 hr light: dark conditions, respectively. Aeration in test vessels was provided 1 day before the start of the experiment. No mortalities were observed in the control. Test fishes were moving slowly as compared to control. On the basis of effect of test chemical on mortality of the test organism, the median lethal concentration (LC50 (96 h)) was determined to be ≥100 mg/l. Thus, test chemical chemical was considered as non-toxic to aquatic fishes at environmental relevant concentrations and hence, considered to be not classified as per the CLP classification criteria.

Description of key information

Short term toxicity to fish was conducted for 96 hrs for assessing the effect of test chemical. The test was performed in accordance to OECD guideline No. 203 “Fish Acute Toxicity Test”. Zebra fish (Danio rerio) of average weight 0.045 g and average length of 1.4 cm was used as a test organism for the study. Test fishes were kept in a static tank in tap water passed through reverse osmosis system, under natural conditions along with proper feed and aeration. During the housing period, test fishes were fed once daily with standard brand fed. The test conditions during the housing of the test organisms were oxygen content of 7.6 mg/l, pH 7.5, water temperature 23.9°C and under a photoperiod of 16:8 hr light: dark conditions, respectively. Test was performed using test chemical concentrations of 0, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, respectively. Total 8 fishes were exposed to test chemical in a 5 lit bowl aquaria containing 4 liters of potable water. The test vessels were placed in a room at a temperature of 23.9°C, pH 7.2, hardness of water 155.5 mg of CaCO3 and under a photoperiod of 16:8 hr light: dark conditions, respectively. Aeration in test vessels was provided 1 day before the start of the experiment. No mortalities were observed in the control. Test fishes were moving slowly as compared to control. On the basis of effect of test chemical on mortality of the test organism, the median lethal concentration (LC50 (96 h)) was determined to be ≥100 mg/l. Thus, test chemical chemical was considered as non-toxic to aquatic fishes at environmental relevant concentrations and hence, considered to be not classified as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

Experimental study of the target chemical and various supporting weight of evidence studies for its read across analogue were reviewed for short term toxicity to fish endpoint which are summarized as below:

 

In an experimental weight of evidence study from study report, the short term toxicity to fish was conducted for 96 hrs for assessing the effect of test chemical. The test was performed in accordance to OECD guideline No. 203 “Fish Acute Toxicity Test”. Zebra fish (Danio rerio) of average weight 0.045 g and average length of 1.4 cm was used as a test organism for the study. Test fishes were kept in a static tank in tap water passed through reverse osmosis system, under natural conditions along with proper feed and aeration. During the housing period, test fishes were fed once daily with standard brand fed. The test conditions during the housing of the test organisms were oxygen content of 7.6 mg/l, pH 7.5, water temperature 23.9°C and under a photoperiod of 16:8 hr light: dark conditions, respectively. Test was performed using test chemical concentrations of 0, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, respectively. Total 8 fishes were exposed to test chemical in a 5 lit bowl aquaria containing 4 liters of potable water. The test vessels were placed in a room at a temperature of 23.9°C, pH 7.2, hardness of water 155.5 mg of CaCO3 and under a photoperiod of 16:8 hr light: dark conditions, respectively. Aeration in test vessels was provided 1 day before the start of the experiment. No mortalities were observed in the control. Test fishes were moving slowly as compared to control. On the basis of effect of test chemical on mortality of the test organism, the median lethal concentration (LC50 (96 h)) was determined to be ≥100 mg/l. Thus, test chemical chemical was considered as non-toxic to aquatic fishes at environmental relevant concentrations and hence, considered to be not classified as per the CLP classification criteria.

 

In a supporting weight of evidence study from authoritative database and other reliable source (1976), short term toxicity to fish study was carried out. Poecilia reticulata (Guppy) of 8.7 mm (6.7 to 10.5 mm) length was used as a test organism. The test organism were grown, bred and maintained in a 20 gallon stainless steel-glass aquaria until testing. Each aquarium was equipped with under-gravel and outside filters, an airstone, and plants to help the fry in hiding from adults. The tanks were kept in an air-conditioned room and the water temperature was maintained with the heaters at 77° to 80°F. The fish were fed at least once but usually twice daily with dried commercial food (TetraMin or Biorell) or brine shrimp hatched from eggs obtained from Metaframe Corporation (San Francisco Brand). The aquaria were kept clean of unconsumed food and other debris by periodic siphoning and partial replacement of the water*. The fish w.ere observed daily for the presence of diseases and dead specimens. They were acclimated to the test conditions for 48 hours during which time the tanks were aerated continuously. Fishes were not fed during the acclimation period. Test fishes were not fed during the study. Test fishes (10 or 20 fish/vessel) were exposed to different conc. of test chemical (0, 191.3, 199, 218.8, 266.5 mg/l) in a five-gallon rectangular glass aquaria provided with a loose fitting plastic cover to prevent evaporation of the water. The fish were distributed to the test aquaria in the random fashion. Columbus city tap water was used to maintain the fish and as experimental water. The tap water was vigorously aerated for at least one week and then was passed through a bed of activated carbon to remove residual chlorine. Finally the water was pumped through 8-micron Whatman filter tube to remove precipitated iron. Sodium hydroxide or hydrochloric acid was added to the test water to adjust pH as needed. Test conditions involve a pH of 7.39 to 7.57, temperature of 24 to 26°C, dissolved oxygen of 7.3 to 8.2 and hardness of 160 mg/l as CaCO3 in a continuous light supplied by fluorescent and incandescent bulb. The number of dead fish in the test tanks were observed and recorded several times daily. With all tests the 24, 48, 72 and 96 hour observations were obtained and recorded. Dead fish were removed immediately with a small net. Based on the effect of test chemical on mortality of the test fish, the 96 hr LC50 value was determined to be 190 mg/l. Thus, based on the LC50 value, test chemical was considered as non-toxic to aquatic fishes and hence, considered to be ‘not classified’ as per CLP classification criteria.

 

For the test chemical, an acute toxicity to fish study was carried out. Study was performed under static conditions for a period of 96 hrs. Micropterus salmoides (Largemouth bass) of 2.8 gm weight was used as a test organism. Test conditions involve a pH of 7.7 to 8.2, temperature of 23°C, dissolve oxygen of 8.1 mg/l and hardness of 202.4 mg/l as CaCO3, respectively. On the basis of the effect of test chemical on mortality of the test organism, the 96 hr LC50 value was determined to be 140.2 mg/l. Thus, based on the LC50 value, test chemical was considered as non-toxic to aquatic fishes and hence, considered to be ‘not classified’ as per CLP classification criteria.

 

On the basis of the above results, test chemical can be considered non-toxic to aquatic fishes at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.