Potassium nitrite

Endpoint summary

Description of key information

Acute oral toxicity:

The experimental study conducted on rabbits for the test chemical was designed to determine acute oral toxicity. The study was conducted in rabbits at the dose concentration of 200 mg/kg bw. 50% mortality was observed. Therefore, LD50 value was considered to be 200 mg/kg, when rabbits were treated with the test chemical via oral route

Acute Inhalation toxicity: The acute inhalation toxicity dose LC50 value was considered to be 85000 mg/m3, when mice were exposed with Potassium nitrite (CAS no: 7758-09-0) by inhalation route for 2 hours.

Acute dermal toxicity:

Under the condition of study; acute dermal toxicity dose (LD50) value for given test chemical was considered to be >2000 mg/kg body weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not exhibit acute dermal toxicity i.e it is acutely non toxic to animals.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from handbook.

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

To determine the acute oral LD50 of the test chemical in rabbit.

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Specific details on test material used for the study:

- Molecular formula :KNO2
- Molecular weight:85.103 g/mol
- Substance type:Inorganic
- Physical state:Solid, white or slightly yellowish

Species:

rabbit

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

not specified

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on oral exposure:

not specified

Doses:

200 mg/kg bw

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

not specified

Statistics:

not specified

Preliminary study:

not specified

Sex:

not specified

Dose descriptor:

LD50

Effect level:

200 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality was observed

Mortality:

50% mortality was observed

Clinical signs:

other: not specified

Gross pathology:

not specified

Other findings:

not specified

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

50% mortality was observed. The acute oral LD50 value was considered to be 200 mg/kg, when rabbits were treated with the test chemical via oral route.

Executive summary:

Acute oral toxicity study of the test chemical was conducted in rabbits. The test chemical at the dose concentration of 200 mg/kg bw was given orally to the test animals and observed for mortality. 50% mortality was observed. The acute oral LD50 value was considered to be 200 mg/kg, when rabbits were treated with the test chemical via oral route.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

300 mg/kg bw

Quality of whole database:

Klimisch Rating 2

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Acute inhalation toxicity of Potassium nitrite (CAS no: 7758-09-0) in mouse.

GLP compliance:

no

Test type:

other: Acute inhalation toxicity

Limit test:

no

Species:

mouse

Strain:

not specified

Sex:

not specified

Route of administration:

inhalation: dust

Duration of exposure:

2 h

Concentrations:

85000 mg/m3

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

- Other examinations performed: Animals were observed for mortality and clinical signs.

Key result

Sex:

not specified

Dose descriptor:

LC50

Effect level:

85 000 mg/m³ air (nominal)

Based on:

test mat.

Exp. duration:

2 h

Remarks on result:

other: No data

Mortality:

50% mortality observed

Clinical signs:

other:

Body weight:

No data

Gross pathology:

No data

Other findings:

No data

Interpretation of results:

other: Not classified

Conclusions:

The acute inhalation toxicity dose LC50 value was considered to be 85000 mg/m3, when mice were exposed with Potassium nitrite (CAS no: 7758-09-0) by inhalation route for 2 hours.

Executive summary:

Acute inhalation toxicity study of Potassium nitrite (CAS no: 7758-09-0)was conducted in mice at the dose concentration of 85000 mg/m3.Animals were observed for mortality and clinical signs.50% mortality was observed. Behavioral changes were observed such as, sleep, excitement, muscle contraction or spasticity. Therefore, LC50valuewasconsidered to be 85000 mg/m3, whenmice were exposed withPotassium nitrite (CAS no: 7758-09-0) by inhalation route for 2 hours.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

85 000 mg/m³ air

Quality of whole database:

K2

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

read-across from supporting substance (structural analogue or surrogate)

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 using standard test guidelines

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

The objective of the study was to assess the dermal toxicity of test chemical after single dose application by dermal route in rats and an observation period of 14 days.

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

other: 2. Wistar 3.Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

2. Species:Rat (Rattus norvegicus)
Strain:Wistar
Sex:Male and Female
Number of Animals:10 (Five per sex)
Supplier/Source:In-House Bred
Health Status:Healthy young adult animals were used for the study. Females were nulliparous and non pregnant
Body weight of animals:
-Male:Minimum: 273 g and Maximum: 280 g (Prior to Treatment)
-Female:Minimum: 236 g and Maximum: 250 g
Acclimatisation:All animals were acclimatized to the test conditions for 8 days prior to test item application.
Identification:During Acclimatization, animals were marked temporary by permanent marker, on their tails. After acclimatization, the animals were marked by toe pad micro tattooing and cage cards. Individual cage cards were labelled with study no., study type, test system, group, dose, sex, animal number experimental start and completion date.
Randomization:Animals were selected manually. No computer generated randomization program was used.
Husbandry ConditionsDiet:All animals were provided conventional laboratory rodent diet Bedding:All cages were provided with corn cobs
Water:Aqua guard filtered tap water was provided ad libitum via drinking bottles.
Husbandry:The animals were housed individually in polycarbonate cages.
Room Sanitation:The experimental room floor and work tops were swept and mopped with disinfectant solution every day.
Cages and water bottle:All the cages and water bottles were changed at least twice every week.
Experimental Room Condition:
Temperature:Minimum: 19.60 °C Maximum: 21.40 °C
Relative humidity:Minimum: 47.40% Maximum: 58.60%
Light-dark-rhythm:12:12
Air Changes:More than 12 changes per hour

3.Prior to application, the test substance was ground in a coffee mill and moistened to achieve a dry
paste by preparing a 90% w/w mixture.
The test material was applied to the shaved intact skin on the backs of each animal and covered with
a gauge pad.
After 24 hours, the pad was removed and the skin gently rinsed with water

Type of coverage:

other: 2. Semiocclusive 3.occlusive

Vehicle:

other: 2. unchanged (no vehicle) 3.Not specified

Details on dermal exposure:

2. Preparation of Application SiteApproximately 24 h prior to treatment, the fur of dorsal area of the trunk (greater than 10% body surface area) of rats was clipped by using clipperTest Item Application ProcedureThe test item was applied uniformly over clipped dorsal area of rat skin. Individual rat was applied with an amount of test item moistened with 0.2 ml distilled water. Test item was held in contact with the skin with a porous gauze dressing (Approx. 10% of body surface area of rat) and non-irritating tape throughout a 24-hour exposure period. It was ensured that the animals cannot ingest the test item. At the end of the exposure period, residual test item was removed by using distilled water. The animals were dosed between 12:45 to 12:58 p.m.Limit TestFive male and five female wistar rats were treated with test item by a single dermal application at the dose level of 2000 mg/kg body weight.Since no test item related mortality was observed, the study was terminated with limit test only.

Duration of exposure:

24 hours

Doses:

2. 2000 mg/kg bw
3. 5000 mg/kg bw

No. of animals per sex per dose:

2. 5 per sex (male and female)-2000 mg/kg bw
3. 5 males/5 females

Control animals:

not required

Details on study design:

2. Preparation of Application Site:Approximately 24 h prior to treatment, the fur of dorsal area of the trunk (approximately 10% body surface area) of rats was clipped by using clipper.
Test Item Application Procedure:The test item was applied uniformly over clipped dorsal area of rat skin. Individual rat was applied with an amount of test item, calculated based on the density (1.0898) and latest body weight. Test item was held in contact with the skin with a porous gauze dressing (Approx. 10% of body surface area of rat) and non-irritating tape throughout a 24-hour exposure period. It was ensured that the animals cannot ingest the test item. At the end of the exposure period, residual test item was removed by using distilled water. The animals were dosed between 11:19 to 11:32 a.m.Limit TestFive male and five female wistar rats were treated with test item by a single dermal application at the dose level of 2000 mg/kg body weight.Since no test item related mortality was observed, the study was terminated with limit test only.

3.- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The rats were observed for mortality, signs of gross
toxicity and behavioral changes at least once daily for 14 days. Body weights were recorded prior to
application and on Days 7 and 14.
- Necropsy of survivors performed: yes,
Necropsies were performed on all animals at study termination.

Statistics:

2. No statistical analysis was performed since the study was terminated with limit test

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: At 2000 mg/kg, all the animals were normal throughout the experimental period.

Remarks:

2.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No mortality observed

Remarks:

3.

Mortality:

2. No mortality was observed at limit dose of 2000 mg/kg body weight of test item during the 14 day observation period
3. All animals survived

Clinical signs:

other: 2. At 2000 mg/kg, all the animals were observed normal throughout the experimental period 3. All animals appeared active and healthy throughout the test. No signs of toxicity were observed

Gross pathology:

2. The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality
3. Gross necropsy findings were unremarkable

Interpretation of results:

practically nontoxic

Conclusions:

Under the condition of study; acute dermal toxicity dose (LD50) value for given test chemical was considered to be >2000 mg/kg body weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not exhibit acute dermal toxicity i.e it is acutely non toxic to animals.

Executive summary:

2. Acute Dermal Toxicity Study of test chemicalinWistar Rats was performed as per OECD No.402.

Five male and five female healthy young adult rats were randomly selected and used for conducting acute dermal toxicity study. Ratsfree from injury and irritation of skin were selected for the study. Approximately, twenty four hours prior to dermal application of test item, greater than 10% of body surface area of each rat was clipped. A limit dose of 2000 mg/ kg body weight of test item moistened with 0.2 ml distilled water was applied by single dermal application and observed for 14 days after treatment. On test day 0, anamount oftestitem moistened with 0.2 ml distilled water was applied directly on the intact skin of clipped area of rats; the porous gauze dressing was put on to the intact skin of clipped area.This porous gauze dressing was covered with a non-irritating tape.After the 24-hour application period, the dressings were removed and the skin was gently wiped with distilled water.The skin reactions were assessed.The animals were observed daily for mortality and clinical signs, during the acclimatization period and post dosing till the termination. All animals were observed for clinical signs at approximately 1, 2, 3 and 4 hours after treatment on day 0 and once daily during test days 1‑14. Mortality was recorded after application on test day 0 and twice daily during days 1-14 (at least once on the day of sacrifice). Local signs / Skin reactions were observed daily from test days 1-14 (in common with clinical signs). Body weights were re­corded on day 0 (prior to application) and on day 7 and 14. All animals were necropsied and examined macroscopically.No mortality was observed in any animal till the end of the experimental period.At 2000 mg/kg, all the animals were normal throughout the experimental period.Mean body weight of male and female animals was observed with gain on day 7 and 14 as compared to day 0 The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality.

Under the conditions of the study,the acute dermal median lethal dose oftest chemicalwas> 2000 mg/kgbody weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not exhibit acute dermal toxicity i.e it is acutely non toxic to animals.

3. Acute dermal toxicity study was conducted as per OECD 402 using the given test chemical in5 males and 5 females Sprague-Dawley, albino rats at the dose concentration of5000 mg/kg bw. Prior to application, the test substance was ground in a coffee mill and moistened to achieve a dry paste by preparing a 90% w/w mixture.  The test material was applied to the shaved intact skin on the backs of each animal and covered with a gauge pad. After 24 hours, the pad was removed and the skin gently rinsed with water. The rats were observed for mortality, signs of gross toxicity and behavioral changes at least once daily for 14 days. Body weights were recorded prior to application and on Days 7 and 14. Necropsies were performed on all animals at study termination. All animals survived, gained weight and appeared active and healthy throughout the test. No signs of toxicity were observed. Gross necropsy findings were unremarkable.  Hence, the LD50 value was considered to be > 5000 mg/kg bw, when 5 males and 5 females SpragueDawley, albino rats were treated with the given test chemical by dermal route occlusively.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

K2

Additional information

Acute oral toxicity:

In different studies, the test chemical has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rabbits and mice for the test chemical. The studies are summarized as below –

The experimental study conducted on rabbits for the test chemical was designed to determine acute oral toxicity. The study was conducted in rabbits at the dose concentration of 200 mg/kg bw. 50% mortality was observed. Therefore, LD50 value was considered to be 200 mg/kg, when rabbits were treated with the test chemical via oral route.

The above study is supported with the study conducted on rabbits. The test chemical was dosed orally at the dose concentration of 108 mg/kg bw. 50% mortality was observed. Therefore, LD50 value was considered to be 108 mg/kg, when rabbits were treated with Potassium nitrite (CAS no: 7758-09-0) via oral route.

This study is supported by the study conducted on mice at the dose concentration of 110 mg/kg bw. 50% mortality was observed. Therefore, LD50 value was considered to be 110 mg/kg, when mice were treated with the test chemical via oral route.

The above study is supported by a similar study conducted on rabbits. The test chemical was given orally at the dose concentration of 300 mg/kg bw. 50% mortality was observed. Therefore, LD50 value was considered to be 300 mg/kg, when rabbits were treated with the test chemical via oral route.

All these studies are also supported by the study conducted in rabbits to determine the acute oral toxicity of the test chemical. Rabbits were dosed with 199 mg/kg bw of the test chemical orally and observed for signs of toxicity. 50% mortality was observed at 199 mg/kgbw. Therefore, the acute oral LD50 value was considered to be 199 mg/kg, when rabbits were treated with the test chemical via oral route.

All the above experimental studies are further supported by the acute oral toxicity study conducted using test chemical in groups of 5 Carworth-Wistar male rats at the dose concentration of 180 mg/kg bw. The test chemical was dissolved in water as10 mg/ml and administered via oral route. The dosages are arranged in a logarithmic series differing by a factor of two. Based upon mortalities during a 14-day observation period, the most probable LD50 value and its fiducial range are estimated by the method of Thompson using the Tables of Weil. The figures in parentheses show limits of ±1.96 standard deviations while the absence of parentheses indicates that no range is calculable because no dosage resulted in fractional mortality. 50% Mortality observed at 180 mg/kg bw. Therefore, LD50 was considered to be180 mg/kg bw, when groups of 5 Carworth-Wistar male rats were treated with test chemical via oral route.

Based on the available results and applying the weight of evidence approach, the acute oral LD50 for the test chemical can be considered to be 300 mg/kgbw. Hence, the test chemical can be classified under the category "Category 3" for acute oral toxicity.

Acute dermal toxicity:

In different studies, the test chemical has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rabbits and mice for the test chemical. The studies are summarized as below –

2. Acute Dermal Toxicity Study of test chemicalinWistar Rats was performed as per OECD No.402.

Five male and five female healthy young adult rats were randomly selected and used for conducting acute dermal toxicity study. Ratsfree from injury and irritation of skin were selected for the study. Approximately, twenty four hours prior to dermal application of test item, greater than 10% of body surface area of each rat was clipped. A limit dose of 2000 mg/ kg body weight of test item moistened with 0.2 ml distilled water was applied by single dermal application and observed for 14 days after treatment. On test day 0, anamount oftestitem moistened with 0.2 ml distilled water was applied directly on the intact skin of clipped area of rats; the porous gauze dressing was put on to the intact skin of clipped area.This porous gauze dressing was covered with a non-irritating tape.After the 24-hour application period, the dressings were removed and the skin was gently wiped with distilled water.The skin reactions were assessed.The animals were observed daily for mortality and clinical signs, during the acclimatization period and post dosing till the termination. All animals were observed for clinical signs at approximately 1, 2, 3 and 4 hours after treatment on day 0 and once daily during test days 1‑14. Mortality was recorded after application on test day 0 and twice daily during days 1-14 (at least once on the day of sacrifice). Local signs / Skin reactions were observed daily from test days 1-14 (in common with clinical signs). Body weights were re­corded on day 0 (prior to application) and on day 7 and 14. All animals were necropsied and examined macroscopically.No mortality was observed in any animal till the end of the experimental period.At 2000 mg/kg, all the animals were normal throughout the experimental period.Mean body weight of male and female animals was observed with gain on day 7 and 14 as compared to day 0 The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality.

Under the conditions of the study,the acute dermal median lethal dose oftest chemicalwas> 2000 mg/kgbody weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not exhibit acute dermal toxicity i.e it is acutely non toxic to animals.

3. Acute dermal toxicity study was conducted as per OECD 402 using the given test chemical in5 males and 5 females Sprague-Dawley, albino rats at the dose concentration of5000 mg/kg bw. Prior to application, the test substance was ground in a coffee mill and moistened to achieve a dry paste by preparing a 90% w/w mixture.  The test material was applied to the shaved intact skin on the backs of each animal and covered with a gauge pad. After 24 hours, the pad was removed and the skin gently rinsed with water. The rats were observed for mortality, signs of gross toxicity and behavioral changes at least once daily for 14 days. Body weights were recorded prior to application and on Days 7 and 14. Necropsies were performed on all animals at study termination. All animals survived, gained weight and appeared active and healthy throughout the test. No signs of toxicity were observed. Gross necropsy findings were unremarkable.  Hence, the LD50 value was considered to be > 5000 mg/kg bw, when 5 males and 5 females SpragueDawley, albino rats were treated with the given test chemical by dermal route occlusively.

Based on the available results and applying the weight of evidence approach, the acute dermal LD50 for the test chemical can be considered to be >2000 mg/kgbw. Hence, the test chemical cannot be classified for acute dermal toxicity.

Acute inhalation toxicity:

Acute inhalation toxicity study of Potassium nitrite (CAS no: 7758-09-0)was conducted in mice at the dose concentration of 85000 mg/m3.Animals were observed for mortality and clinical signs.50% mortality was observed. Behavioral changes were observed such as, sleep, excitement, muscle contraction or spasticity. Therefore, LC50 valuewasconsidered to be 85000 mg/m3, whenmice were exposed withPotassium nitrite (CAS no: 7758-09-0) by inhalation route for 2 hours.

Acute Inhalation toxicity study was conducted using the given test chemical inrats at the dose concentration of88.8 mg/L via inhalation route for 4 hours exposure. Animals were observed for mortality and clinical signs. No Mortality observed at 88.8 mg/L. No significant toxicological effects were observed.

Hence, the LC50 value was considered to be >88.8 mg/L, when rats were treated with the given test chemical by inhalation route for 4 hours exposure.

Based on the available results for target chemical and supporting chemical, the acute inhalation LC50 for the test chemical can be considered to be 85000

mg/m3

Hence, the test chemical cannot be classified for acute inhalation toxicity.

Justification for classification or non-classification

Based on the available results and applying the weight of evidence approach, the acute oral LD50 for the test chemical can be considered to be 300 mg/kgbw. Hence, the test chemical can be classified under the category "Category 3" for acute oral toxicity.

The acute dermal LD50 for the test chemical can be considered to be >5000 mg/kg bw and the LC50 for Acute inhalation toxicity was considered to be 85000 mg/m3. Thus, the test chemical cannot be classified for Acute dermal and Acute inhalation toxicity.