Potassium iodate

Endpoint summary

Description of key information

Repeated dose toxicity: Oral

The study was designed to investigate the subacute repeated dose toxicity effects of the test chemical to Beltsville guinea pigs(male/female) by oral route in an overall estimation period of 28 days. First group (6 animals per sex in each dose group) was fed a dry Purina Rabbit Chow in the drinking water equivalent to 12.5 mg/kg bw/day (0.05 % concentration) test chemical in the diet. The second group received only the test chemical equivalent to125 mg/kg bw/day (0.50 % concentration), and the third group as control received distilled water. During the study period body weight, haematology, histopathology, opthalmoscopic examination, gross pathology, water consumption, total body weight and compound intake were examined. The blood examinations failed to show any striking changes related to the target compound. All animals remained in good physical condition during the 4-week study period. No gross changes were observed on postmortem examination and no retinal degeneration or other significant histologic changes were noted. Thus from overall dissussion of the study, the NOAEL (no observed adverse effect level) for repeated dose oral toxicity was considered to be 125 mg/kg bw/day.

Repeated dose toxicity: Inhalation

The test substance Potassium iodate has very low vapor pressure (6.82E-19 Pa) also the particle size distribution of the substance was found to vary in the size of 150 µm to 500 µm, so the potential for the generation of inhalable vapours of Potassium iodate is low. Moreover the normal conditions of use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be unlikely to occur and therefore repeated dose toxicity via the inhalation route was considered for waiver.

 

Repeated dose toxicity : Dermal

The results for acute toxicity by the dermal route indicate the LD50 value to be greater than 2000 mg/kg body weight. In addition, skin contact in production and/or use is likely but can be avoided by wearing the protective equipemt such as gloves during handling and the physicochemical and toxicological properties suggest no potential for significant rate of adsorption through the skin. Thus, given the above considerations, it is assumed that Potassium iodate shall not exhibit repeated dose toxicity by the dermal route.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

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

Justification for type of information:

Data is from peer reviewed poublication

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

The subacute (28 days) study was conducted to evaluate the toxic effects of repeated administration of the test chemical to guinea pigs by the oral route.

GLP compliance:

not specified

Limit test:

no

Species:

guinea pig

Strain:

other: Beltsville

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: N/A
- Housing:Each animal was housed in a separate cage
- Diet (e.g. ad libitum):dry Purina Rabbit Chow ad libitum
- Water (e.g. ad libitum):ad libitum

Route of administration:

oral: drinking water

Vehicle:

water

Details on oral exposure:

1st group : 12.5 mg/kg bw/day KIO3 in the drinking water.
2nd group : 125 mg/kg bw/day KIO3
3rd group (Control group):Control group was given distilled water.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

28 days

Frequency of treatment:

Daily

Remarks:

Doses / Concentrations:
0,12.5, 62.5,125 mg/kg bw/day
Basis:

No. of animals per sex per dose:

Control: 6 males and 6 females
12.5 mg/kg bw/day: 6 males and 6 females
125 mg/kg bw/day:6 males and 6 females

Control animals:

yes, concurrent vehicle

Details on study design:

Because the 125 mg/kg bw/day KI03 group drank so little, the iodate concentration was reduced to 62.5 mg/kg bw/day after the fourteenth day.

Observations and examinations performed and frequency:

BODY WEIGHT: Yes
- Average body weight examined.
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
Total water consumption observed.

OPHTHALMOSCOPIC EXAMINATION: Yes
The eyes of each one were examined microscopically.

HAEMATOLOGY: Yes
Blood samples were taken from two males and females in each group 5-6 days before the end of the 4-week experimental period.
Following parameters were examined:
red cell count, hematocrit, hemoglobin, white cell count, and differential counts

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
Sacrifice : yes
The animals were killed with ether and given a postmortem examination.
HISTOPATHOLOGY: Yes
Microscopically organs were studied in only a few animals in each group.

Statistics:

No data

Clinical signs:

not specified

Mortality:

not specified

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

smaller gain in body weight

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

consumed less iodate

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

effects observed, treatment-related

Description (incidence and severity):

Water consumption increased

Ophthalmological findings:

no effects observed

Description (incidence and severity):

No retinal degeneration was observed.

Haematological findings:

no effects observed

Description (incidence and severity):

Blood examinations failed to show any striking changes

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

No adverse effects observed

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

No gross changes were observed on postmortem examination.

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Details on results:

All animals remained in good physical condition during the 4-week study period.

Dose descriptor:

NOAEL

Effect level:

125 other: mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Basis for effects : Haematology, Histopathology, Opthalmoscopic examination, Gross pathology

Critical effects observed:

not specified

Conclusions:

In a sub acute repeated dose toxicity study of the test chemical, it showed no effect on male and female guinea pigs when present in the diet at a level upto 125 mg/kg bw/day (0.50 % concentration) for a 28 days study period. Thus the NOAEL (no observed adverse effect level) for repeated dose oral toxicity was considered to be 125 mg/kg bw/day.

Executive summary:

The study was designed to investigate the subacute repeated dose toxicity effects of the test chemical to Beltsville guinea pigs(male/female) by oral route in an overall estimation period of 28 days. First group (6 animals per sex in each dose group) was fed a dry Purina Rabbit Chow in the drinking water equivalent to 12.5 mg/kg bw/day (0.05 % concentration) test chemical in the diet. The second group received only the test chemical equivalent to125 mg/kg bw/day (0.50 % concentration), and the third group as control received distilled water. During the study period body weight, haematology, histopathology, opthalmoscopic examination, gross pathology, water consumption, total body weight and compound intake were examined. The blood examinations failed to show any striking changes related to the target compound. All animals remained in good physical condition during the 4-week study period. No gross changes were observed on postmortem examination and no retinal degeneration or other significant histologic changes were noted. Thus from overall dissussion of the study, the NOAEL (no observed adverse effect level) for repeated dose oral toxicity was considered to be 125 mg/kg bw/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

125 mg/kg bw/day

Study duration:

subacute

Species:

guinea pig

Quality of whole database:

The data is K2 level as the data has been obtained from the experimental study from the reliable journal ‘Toxicology'.

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

repeated dose toxicity: inhalation

Data waiving:

exposure considerations

Justification for data waiving:

other:

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Waiver

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

repeated dose toxicity: dermal

Data waiving:

other justification

Justification for data waiving:

other:

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Waiver

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Data available for the test chemical was reviewed to determine the toxic nature. The studies are as mentioned below:

Repeated dose toxicity: Oral

The study was designed to investigate the subacute repeated dose toxicity effects of the test chemical to Beltsville guinea pigs(male/female) by oral route in an overall estimation period of 28 days. First group (6 animals per sex in each dose group) was fed a dry Purina Rabbit Chow in the drinking water equivalent to 12.5 mg/kg bw/day (0.05 % concentration) test chemical in the diet. The second group received only the test chemical equivalent to125 mg/kg bw/day (0.50 % concentration), and the third group as control received distilled water. During the study period body weight, haematology, histopathology, opthalmoscopic examination, gross pathology, water consumption, total body weight and compound intake were examined. The blood examinations failed to show any striking changes related to the target compound. All animals remained in good physical condition during the 4-week study period. No gross changes were observed on postmortem examination and no retinal degeneration or other significant histologic changes were noted. Thus from overall dissussion of the study, the NOAEL (no observed adverse effect level) for repeated dose oral toxicity was considered to be 125 mg/kg bw/day.

The subacute repeated dose oral toxicity study was performed to determine the effects of the test chemical to White Swiss mice (female) by oral (drinking water) route in an overall estimation period of 15-16 weeks. First and second lot of animals was fed a Purina Laboratory Chow in the drinking water equivalent to71.42, 142.85 or 357.14mg/kg bw/day (0.05%, 0.10%, or 0.25%, respectively) test chemical in the diet. The third and forth lot of animals received only the test chemical equivalent to714.28 or 1071.42 mg/kg bw/day (0.50% and 0.75%, respectively), and 928.57 mg/kg bw/day (0.65% concentration) KI (potassium iodide), and their corresponding control groups received only water.During the study period body weight, haematology, body weight, mortality, water consumption, total body weight and compound intake were examined.The observations showed hemosider in deposits in the renal convoluted tubules in nearly all mice which received 714.28 mg/kg bw/day (0.50% concentration) test chemical for 16 weeks, and increased hemolysis due to the iodate. A slightly lower mortality at 714.28 mg/kg bw/day was also observed.Thus from overall discussion of the study, LOAEL (lowest observed adverse effect level) for repeated dose oral toxicity was considered to be 714.28 mg/kg bw/day.

The study was designed to investigate the subacute repeated dose oral toxicity effects of the test chemical in a concentration of 6, 60, 90 or 100 mg/kg to Mongrel dogs (male/female), given in milk or by capsule for a study period of 68-192 days. In the study a total of four dogs were examined, where 3 dogs received final doses of the test chemical at 60 mg/kg, and the fourth animal had received doses of the test chemical up to 100 mg/kg. Canned dog food was offered to each dog after administration of the the test chemical. During the study periodoccasional emesis, slight anorexia, listlessness,body weight and weight gain,autopsy, hemorrhagic necrosis,food efficiency, water consumption, urinalysis and histopathology were examined. In the clinical examination the emetic dose ranged from 60 to 66 mg/kg in 2 dogs to 75 mg/kg for the third, but the fourth failed to vomit after receiving 5 doses of 100 mg/kg during a week. All 4 dogs showed a weight gain. One dog showed an abnormal appetite and thirst. Haematological examination showed few changes from the pretreatment values, except for a slight decrease in red cell count and a moderate decrease in white cell count. The test chemical also contributes to show histopathological changes. Thus from overall observation of the study, the LOAEL (Lowest observed adverse effect level) for repeated dose oral toxicity was considered to be 60 mg/kg.

Repeated dose toxicity: Inhalation

The test substance Potassium iodate has very low vapor pressure (6.82E-19 Pa) also the particle size distribution of the substance was found to vary in the size of 150 µm to 500 µm, so the potential for the generation of inhalable vapours of Potassium iodate is low. Moreover the normal conditions of use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be unlikely to occur and therefore repeated dose toxicity via the inhalation route was considered for waiver.

 

Repeated dose toxicity : Dermal

The results for acute toxicity by the dermal route indicate the LD50 value to be greater than 2000 mg/kg body weight. In addition, skin contact in production and/or use is likely but can be avoided by wearing the protective equipemt such as gloves during handling and the physicochemical and toxicological properties suggest no potential for significant rate of adsorption through the skin. Thus, given the above considerations, it is assumed that Potassium iodate shall not exhibit repeated dose toxicity by the dermal route.

Based on the data available, the test chemical does not exhibit toxic nature upon repeated exposure by oral, dermal and inhalation route of exposure. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.

Justification for classification or non-classification

Based on the data available, the test chemical does not exhibit toxic nature upon repeated exposure by oral, dermal and inhalation route of exposure. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.