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Administrative data

Description of key information

Animal studies with sodium chlorate show a low acute toxicity after inhalation (LC50(4.5h) > 5.59 mg/l), dermal (LD50(24h)  > 2000 mg/kg bw) and oral (LD50 = 4950-6250 mg/kg bw) exposure. Numerous human case studies are reported. Due to vomiting occurring, sometimes rapidly after ingestion, the absorbed quantity is often uncertain. Therefore, variability occurs in the doses causing lethality. Since the 1960s, survival to higher dose levels of chlorate, up to 200 grams (± 3.33 g/kg bw), has increased due to the possibility of dialysis treatment in case of renal failure.


 


Acute toxicity of chlorate is mediated by methaemoglobin. There are marked species differences in susceptibility to form methaemoglobin. Humans are more affected than rodent species. Infants, particularly neonates, are more prone to methaemoglobinemia than older children and adults and are consequently likely to be more susceptible to the toxicity of chlorate. Related to the rapid urinary excretion, the highest levels of chlorates are reached in the kidneys. Nephrotoxicity also seems mediated by methaemoglobin catalysis.


 


An evaluation by the French poison control center of sensitivity of humans to sodium chlorate compared to rats led to the following conclusion: If one considers that 50% methemoglobinemia starts to induce signs that may lead to death in the absence of treatment, the dose would be about 20 g / kg for the whole population and 4.5 g / kg for the most sensitive part is the same range as rats.


 


Despite the low acute toxicity in animals, sodium chlorate has an harmonised classification (index No. 017-005-00-9, ATP0) as Acute Tox. 4 *, H302 (* minimum classification for the category) based on human experience indicating that classification of sodium chlorate is justified.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Referenceopen allclose all

Endpoint:
acute toxicity: oral
Type of information:
other: review
Adequacy of study:
supporting study
Study period:
1999-2008
Reliability:
other: review
Rationale for reliability incl. deficiencies:
other: Review of poison control center data in France in relation to poisoning incidents with sodium chlorate and toxicity in humans
Conclusions:
1> The classification for acute toxicity: according to the test in rats the LD50 is greater than 2000 mg / kg and the product is not classified. The interpretation of these human data in terms of death is very difficult indeed reflect certain death at doses much lower than others that have led to few symptoms and occurred in some cases with very low methaemoglobinaemia (other associated toxic ?). If one considers that 50% methemoglobinemia starts to induce signs that may lead to death in the absence of treatment, the dose would be about 20 g / kg for the whole population and 4.5 g / kg for the most sensitive part is the same range as rats.

2> Limit values:
a. Acceptable daily intake (ADI) is proposed for 0045 mg / kg / day or 4200 times less than the dose inducing 3% Methemoglobinemia in the general population. The occurrence of methemoglobinemia in these circumstances, even in cases of repeated dose seems unlikely.
b. The acceptable dose for the operator proposed is 0.35 mg / kg / day or 420 times less than the dose inducing 3% Methemoglobinemia in the general population. The occurrence of methemoglobinemia in these circumstances, repeated dose seems unlikely.
Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
23 October 1990 - 11 January 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study was performed under GLP and according to internationally accpeted guidelines.
Qualifier:
according to guideline
Guideline:
EPA OPP 81-1 (Acute Oral Toxicity)
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Hilltop Lab Animals, Scottdale, PA
- Age at study initiation: Young adults
- Weight at study initiation: weighing 222 - 293 grams
- Fasting period before study: Approximately 18 hours prior to selction and test initiation
- Housing: individually in suspended stainless steel caging with mesh floors
- Diet (e.g. ad libitum): Pelleted Purina Rat Chow #5012, ad lib
- Water (e.g. ad libitum): Tap water supplied by automatic water system, ad lib
- Acclimation period: 28 or 30 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23
- Humidity (%): no info
- Air changes (per hr): no info
- Photoperiod (hrs dark / hrs light): no info


IN-LIFE DATES: Rangefinding: From: November 29, 1990 To: December 7, 1990;
Test: From: December 19, 1990 To: January 11, 1991
Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
VEHICLE
- Concentration in vehicle: 50% w/w solution in distilled water
- Amount of vehicle (if gavage): no info
- Justification for choice of vehicle: no info
- Lot/batch no. (if required): no info
- Purity: no info


MAXIMUM DOSE VOLUME APPLIED: approximately 7 ml/kg
Doses:
- range finding study: 300, 600, 1250, 2500 and 5000 mg/kg bw; (one male and one female per dose)
- full acute oral limit test 1: 5000 mg/kg bw
- full acute oral limit test 2: 2000 mg/kg bw
No. of animals per sex per dose:
full acute oral limit test: 5
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: rats were observed at 1, 2 and 4 hours post-dosing and at least once daily thereafter for signs of gross toxicity and mortality. Bodyweights were recorded initially, on day 7, at termination (day 14) or after death.
- Necropsy of survivors performed: yes, gross necropsies were performed on the animals that died during the study and at termination of the study
- Other examinations performed: clinical and behavioural signs, body weight, histopathology
Statistics:
No.
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Mortality:
Dose group 5000 mg/kg bw
- one female died
- Time of death: one day after dosing
Dose group 2000 mg/kg bw
- no animal died
Clinical signs:
- Dose group 5000 mg/kg bw
Shortly after dosing several animals appeared lethargic (2 females and 2 males) and had a hunched posture (2 females and 2 males). By 24 hours these conditions were no longer evident and survivors appeared active and healthy for the remainder of the test period. The female animal that died showed lethargy and ano-genital staining.
- Dose group 2000 mg/kg bw
one male animal, lethargic and hunched posture. By 24 hours these conditions were no longer evident and survivors appeared active and healthy for the remainder of the test period.
Body weight:
- Dose group 5000 mg/kg bw
all survivors gained weight between days 0 and 7 and again between days 7 and 14, although the weight gain in most cases was marginal.
- Dose group 200 mg/kg bw
all survivors gained weight between days 0 and 7 and again between days 7 and 14 at a rate generally expected for the strain and age of animals used.
Gross pathology:
- Dose group 5000 mg/kg bw
The female that died showed green discoloration of the intestines, a light green fluid in the stomach, pink liquid in the abdominal cavity and dark red lung discoloration. Other animals showed no significant abnormalities at necropsy, moderate redness in the lungs of all animals.
- Dose group 2000 mg/kg bw
Negligible, slight to moderate redness in the lungs of all animals.
Conclusions:
LD50 > 5000 mg/kg bw
Executive summary:

The study was performed in accordance with EPA Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, November 1984, Acute Exposure, oral Toxicity Limit Test (equivalent to OECD Guideline 401 - Acute Oral Toxicity -). Furthermore, the study was designed and performed according to Good Laboratory Practice Standards.

The test material, Sodium Chlorate Crystal, was evaluated for its acute oral toxicity potential in 30 Sprague Dawley rats. Ten animals were used in a rangefinding study (dose levels: 5, 2.5, 1.25, 0.6 and 0.3 g/kg bw). Thereafter Sodium Chlorate was administered as gavage doses in a first (5.0 g/kg and second (2.0 g/kg) limit test. No mortality occurred in animals dosed at 2.0 g/kg and 1 animal died at dose level 5.0 g/kg. Clinical signs of toxicity at 5.0 g/kg included hunched posture and reduced feces, which were no longer evident on Day 3. At 2.0 g/kg only hunched posture was observed at 2 -4 hours post dosing in one male. There was no meaningful effect on body weight gain in animals surviving to termination. Necropsy findings at 5.0 g/kg showed green discoloration of the intestines, a light green fluid in the stomach, pink liquid in the abdominal cavity and dark red lung discoloration. At 2.0 g/kg only slight to moderate redness in the lungs of all animals was observed.

Conclusions: The acute oral LD50 of Sodium Chlorate Crystal was determined to be greater than 5000 mg/kg bw.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
5 000 mg/kg bw

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
Study period:
January 1991 - February 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study performed according to guideline and under GLP.
Qualifier:
according to guideline
Guideline:
EPA OPP 81-3 (Acute inhalation toxicity)
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Principles of method if other than guideline:
Two limit tests are performed:
The target gravimetric chamber concentration (5 mg/mL which is also required by OECD 403) and particle size distribution (25% < 1 micron) could not be reached simultaneously. Therefore two experiments were performed in which one of both parameters was optimal.
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Hilltop Lab Animals, Scottdale, PA
- Age at study initiation: Young adult
- Weight at study initiation: weighing 216 - 249 g
- Fasting period before study: no info
- Housing: individually in suspended stainless steel caging with mesh floors
- Diet (e.g. ad libitum): Pelleted Purina Rat Chow, ad lib
- Water (e.g. ad libitum): Tap water supplied by automatic water system, ad lib
- Acclimation period: 7 or 12 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): Limit test 1: 22 - 23; Limit test 2: 21 - 24
- Humidity (%): no info
- Air changes (per hr): no info
- Photoperiod (hrs dark / hrs light): no info


IN-LIFE DATES: From: January 30, 1991 To: February 25, 1991
Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
Vehicle:
other:
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rectangular perspex gravimetric chamber with a volume of 100 liters operated under slight negative pressure.
- Exposure chamber volume: 100 L
- Method of holding animals in test chamber: individually in stainless steel mesh cages within the inhalation chamber.
- Source and rate of air: breathing grade air from a compressed gas cylinder and additional "diluent" air from a filtered conditioned ambient source. Air flows were 26.1 – 28.2 lpm (limit test 1) and 34.6 – 38.8 lpm (limit test 2).
- Method of conditioning air: breathing grade air from a compressed gas cylinder and additional "diluent" air from a filtered conditioned ambient source.
- System of generating particulates/aerosols: 1/4 inch JCO atomizer (Spraying Systems Inc.) #2050 fluid cap and #73160 air cap. The test material was metered to the atomization nozzle through size 14 tygon tubing using a Master Flex Pump (Model 7520-35). In an attempt to affect the particle size distribution during Limit Test #1 and most of its associated trials, a circular tin disk (diameter 9.5 cm) was placed inside the exposure chamber 53 to 106 mm in front of the nebulizer during aerosol generation. Since this process tended to drastically lower attainable chamber concentration, it was not used for Limit Test #2.
- Method of particle size determination: An eight-stage Andersen cascade impactor was used to assess the particle size distribution of the test atmosphere. The filter paper collection stages were weighed before and at least 10 minutes after each sampling to determine the mass collected at each stage on a dry weight basis. The MMAD and GSD were determined graphically using two-cycle logarithmic probit axes.
- Treatment of exhaust air: no info
- Temperature, humidity, pressure in air chamber:
Chamber temperature range (°C): 22-23 (limit test 1) and 19-20 (limit test 2)
Rel. Humidity (% RH): 32.1-39.0 (limit test 1) and 27.2-32.5 (limit test 2)
Chamber under slight negative pressure.
T90 (min): 6-8
T99 (min): 13-17


TEST ATMOSPHERE
- Brief description of analytical method used: Gravimetric samples were withdrawn on 5 or 6 occasions from the breathing zone of the animals. Samples were collected using membrane filters in filter holders attached by 1/4 inch tygon tubing to a sampling pump. Filter papers were weighed before and at least 10 minutes after each sampling to determine the mass collected on a dry weight basis. On several occasions filters were re-weighed after 30 minutes to verify that complete drying had occurred. The collections were carried out for 1 minute at air flows of 4 lpm.
- Samples taken from breathing zone: yes


VEHICLE
- Composition of vehicle (if applicable): distilled water
- Concentration of test material in vehicle (if applicable): test material was aerosolized as a 33.3% w/w solution in distilled water
- Justification of choice of vehicle: no info


TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):
Limit test 1: sample 1, MMAD = 2.1 µm and GSD = 1.9; sample 2, MMAD = 2.2 and GSD = 2.0
Limit test 2: sample 1, MMAD = 3.0 µm and GSD = 1.7; sample 2, MMAD = 3.0 and GSD = 1.8
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4.5 h
Concentrations:
limit test 1: 1.42 ± 0.38 mg/l (nominal concentration = 637.5 mg/L, 33.3% w/w solution)
limit test 2: 5.59 ± 1.64 mg/l (nominal concentration = 229.9 mg/L, 33.3% w/w solution)
No. of animals per sex per dose:
5
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed before exposure commencement, every 15 minutes during the first exposure hour, and every 30 minutes thereafter through exposure termination. On removal from the chamber the animals were individually examined. Bodyweights were recorded prior to exposure and on days 1, 2, 4, 7, 10 and 14.
- Necropsy of survivors performed: yes, All survivors to termination were euthanized by diethyl ether inhalation and subjected to necropsy examination. The lungs of all animals were removed and placed in buffered formalin.
- Other examinations performed: clinical signs, body weight, histopathology
Statistics:
Not required.
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.59 mg/L air
Exp. duration:
4.5 h
Mortality:
- Limit test 1: no mortality
- Limit test 2: no mortality
Clinical signs:
other:
Body weight:
- Limit test 1: All animals gained weight over the 14-day observation period.
- Limit test 2: All animals gained weight overall.
Gross pathology:
- Limit test 1: Red discoloration of the lungs in most animals (4 males and 2 females). Small cysts (1 female) or uneven texture (1 female and 1 male) was evident on the surface of the lungs.
- Limit test 2: Red discoloration of the lungs in all animals. The jejunum of 2 females from was red in colour.
Interpretation of results:
Category 5 based on GHS criteria
Remarks:
Migrated information
Conclusions:
The acute (4.5 h) inhalation LC50 of aerosolized Sodium Chlorate Crystal was determined to be greater than 5.59 mg/L in males and females. Because higher concentrations than 5.59 mg/L had not been tested and effects at those concentrations are unknown the test material was classified in Category 5 according to OECD-GHS.
Executive summary:

Sodium Chlorate was evaluated for its acute inhalation toxicity potential in albino rats. The study was performed in accordance with EPA Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, November 1984, Acute Exposure, acute Inhalation Toxicity. Similar to OECD Guideline 403 (Acute Inhalation Toxicity). The study was designed and performed according to Good Laboratory Practice Standards.

The target gravimetric chamber concentration (5 mg/mL, which is also required by OECD 403) and particle size distribution (25% 1 micron) could not be reached simultaneously. Therefore two limit tests were performed in which one of both parameters was optimal. Five males and five females were assigned to each study and they were exposed for 4 ½ hours to an aerosol (test atmosphere generated from a 33.3% w/w solution in distilled water) at a level of 1.42 mg/L (limit test 1) and 5.59 mg/L (limit test 2). There was no mortality during both studies. Clinical signs of toxicity included facial staining, reduced movement, test material-stained fur and closed eyes and in limit test 2 also irregular respiration and hunched posture, which were no longer evident on Day 1 (limit test 1) or Day 2 (limit test 2). Observations were up to 14 days and all animals gained weight overall. The gross necropsy showed red discoloration of the lungs in most animals.

The acute (4.5 h) inhalation LC50 of aerosolized Sodium Chlorate Crystal was determined to be greater than 5.59 mg/L in males and females. Because higher concentrations than 5.59 mg/L had not been tested and effects at higher concentrations are unknown the test material was classified in Category 5 according to OECD-GHS.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LC50
Value:
5 590 mg/m³

Acute toxicity: via dermal route

Link to relevant study records

Referenceopen allclose all

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
26 June 1991 - 07 July 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study performed according to standard US EPA protocol and under GLP.
Qualifier:
according to guideline
Guideline:
EPA OPP 81-2 (Acute Dermal Toxicity)
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Principles of method if other than guideline:
Principles other than OECD Guideline:
- 24-h occlusive application
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Davidson's Mill Farm, S. Brunswick, NJ
- Age at study initiation: no info
- Weight at study initiation: males 2.6-2.8 kg; females 2.5-2.8 kg
- Housing: individually in suspended stainless steel caging with mesh floors
- Diet (e.g. ad libitum): Purina Rabbit Chow, ad lib
- Water (e.g. ad libitum): tap water, ad lib
- Acclimation period: 15 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21
- Humidity (%): no info
- Air changes (per hr): no info
- Photoperiod (hrs dark / hrs light): no info


IN-LIFE DATES: From: June 26, 1991 To: July 10, 1991
Type of coverage:
occlusive
Vehicle:
other: none, test substance applied moistened with water (0.3 ml per 1000mg)
Details on dermal exposure:
TEST SITE
- Area of exposure: 10.2x5.08cm2 (4x2") (dorsal and ventral surfaces from scapular to pelvic area)
- % coverage: no info (10% clipped)
- Type of wrap if used: an adhesive-backed gauze patch containing test substance was placed on each rabbit. The patches and entire trunk of each rabbit were then wrapped with tape to aid in maintaining test patch position and to minimize evaporation. Neck collars were then placed on each rabbit.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): after 24-h the patches and collars were removed and the exposed surface was gently wiped clean of any residual test substance.
- Time after start of exposure: 24-h


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw (completely moistened with distilled water)
- Concentration (if solution): not applicable (sample moistened with approximately 0.3 ml of distilled water per gram of test substance).
- Constant volume or concentration used: yes
- For solids, paste formed: yes


VEHICLE
- Amount(s) applied (volume or weight with unit): 0.3 ml per gram of test substance
- Concentration (if solution): not applicable
Duration of exposure:
24-h
Doses:
2000 mg/kg bw
No. of animals per sex per dose:
10 (5 males and 5 females)
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: the animals were observed at 1, 2, and 4 h after dosing and once daily for the next 14 days. Body weight was measured at day 0, 7 and 14.
- Necropsy of survivors performed: yes, necropsy was performed on all survivors.
- Other examinations performed: clinical signs, body weight, histopathology.
Statistics:
No statistics.
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Mortality:
No mortality.
Clinical signs:
All the animals appeared healthy and active during the study period. Slight to moderate skin irritation was observed at the dose site for several days after dosing.
Body weight:
All animals gained weight over the 14-day observation period.
Gross pathology:
Gross necropsy findings were unremarkable. All tissues and organs appeared normal.
Interpretation of results:
Category 5 based on GHS criteria
Remarks:
Migrated information
Conclusions:
The Single Dose Acute Dermal LD50 of Sodium Chlorate Crystal, moistened with distilled water and applied to the skin for 24 hours, is greater than 2000 mg/kg bw. Because higher concentrations than 2000 mg/kg had not been tested and effects at those higher concentrations are unknown the test material was classified in Category 5 according to OECD-GHS.
Executive summary:

Sodium Chlorate was evaluated for its acute dermal toxicity potential in albino rabbits. The study was performed in accordance with EPA Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, November 1984, Acute Exposure, Dermal Toxicity. Similar to OECD Guideline 402 (Acute Dermal Toxicity). The study was designed and performed according to Good Laboratory Practice Standards.

For 24 hours 2000 mg/kg bw test substance (moistened with approximately 0.3 ml of distilled water per gram of test substance) is applied to the skin of ten albino rabbits. A single 24 -hour, occluded application of the test material to the intact skin produced a slight to moderate skin irritation. No mortality occurred. There were no signs of gross toxicity, adverse pharmacologic effects or abnormal behaviour. All animals gained weight over the 14-day observation period. The gross necropsy showed that all tissues and organs appeared normal.

The Single Dose Acute Dermal LD50 of Sodium Chlorate Crystal, moistened with distilled water and applied to the skin for 24 hours, is greater than 2000 mg/kg bw. Because higher concentrations than 2000 mg/kg had not been tested and effects at those higher concentrations are unknown the test material was classified in Category 5 according to OECD-GHS.

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
December 1990 - January 1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study performed according to standard US EPA protocol and under GLP. The exposure was not maximized (the solid test item was not moistened before application), therfore this study was not conclusive.
Qualifier:
according to guideline
Guideline:
EPA OPP 81-2 (Acute Dermal Toxicity)
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Principles of method if other than guideline:
Principles other than OECD Guideline:
- 24-h occlusive application
- Test substance was not moistened
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Davidson's Mill Farm, S. Brunswick, NJ
- Age at study initiation: no info
- Weight at study initiation: males 2.2-2.6 kg; females 2.1-2.5 kg
- Housing: individually in suspended stainless steel caging with mesh floors
- Diet (e.g. ad libitum): Purina Rabbit Chow, ad lib
- Water (e.g. ad libitum): tap water, ad lib
- Acclimation period: 9 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-21
- Humidity (%): no info
- Air changes (per hr): no info
- Photoperiod (hrs dark / hrs light): no info


IN-LIFE DATES: From: December 6, 1990 To: December 20, 1990
Type of coverage:
occlusive
Vehicle:
other: none, test substance applied as received and undiluted
Details on dermal exposure:
TEST SITE
- Area of exposure: 10.2x5.08cm2 (4x2") (dorsal and ventral surfaces from scapular to pelvic area)
- % coverage: no info (10% clipped)
- Type of wrap if used: an adhesive-backed gauze patch containing test substance was placed on each rabbit. The patches and entire trunk of each rabbit were then wrapped with tape to aid in maintaining test patch position and to minimize evaporation. Neck collars were then placed on each rabbit.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): after 24-h the patches and collars were removed and the exposed surface was gently wiped clean of any residual test substance.
- Time after start of exposure: 24-h


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw
- Concentration (if solution): 2000 mg/kg bw
- Constant volume or concentration used: yes
- For solids, paste formed: no


VEHICLE
- Amount(s) applied (volume or weight with unit): not applicable, the sample was applied as received.
- Concentration (if solution): not applicable
Duration of exposure:
24-h
Doses:
2000 mg/kg bw
No. of animals per sex per dose:
10 (5 males + 5 females)
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: the animals were observed at 1, 2, and 4 h after dosing and at least once daily for the next 14 days. Body weight was measured at day 0, 7 and 14.
- Necropsy of survivors performed: yes, necropsy was performed on all survivors.
- Other examinations performed: clinical signs, body weight, histopathology.
Statistics:
No statistics.
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Mortality:
No mortality.
Clinical signs:
One female had diarrhoea and ano-genital staining on day 14 and lost 200g weight all the other animals appeared healthy and active during the study period.
Body weight:
One female lost weight (200 g); all other animals gained weight over the 14 day period.
Gross pathology:
Necropsy findings on the survivors were unremarkable. All tissues and organs appeared normal.
Interpretation of results:
Category 5 based on GHS criteria
Remarks:
Migrated information
Conclusions:
The Single Dose Acute Dermal LD50 of Sodium Chlorate Crystal, applied as received, undiluted to the skin for 24 hours, is greater than 2000 mg/kg bw. Because higher concentrations than 2000 mg/kg had not been tested and effects at those higher concentrations are unknown the test material was classified in Category 5 according to OECD-GHS.
Executive summary:

Sodium Chlorate Crystalwas evaluated for its acute dermal toxicity potential in albino rabbits. The study was performed in accordance with EPA Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, November 1984, Acute Exposure, Dermal Toxicity Limit Test. Similar to OECD Guideline 402 (Acute Dermal Toxicity). The study was designed and performed according to Good Laboratory Practice Standards.

For 24 hours 2000 mg/kg bw undiluted test substance is applied to the skin of ten albino rabbits. A single 24 -hour, occluded application of the test material to the intact skin produced in one female diarrhoea. This female also showed ano-genital staining on day 14 and a lost of weight. No mortality occurred. All other animals gained weight over the 14-day observation period. There were no signs of gross toxicity, adverse pharmacologic effects or abnormal behaviour. The gross necropsy showed that all tissues and organs appeared normal.

The Single Dose Acute Dermal LD50 of Sodium Chlorate Crystal, applied as received, undiluted to the skin for 24 hours, is greater than 2000 mg/kg bw. Because higher concentrations than 2000 mg/kg had not been tested and effects at those higher concentrations are unknown the test material was classified in Category 5 according to OECD-GHS.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
2 000 mg/kg bw

Additional information

Animal studies show a relatively low acute toxicity with oral LD50 around 5 grams/kg or higher. In humans, doses of 5 to 10 grams (± 83-166 mg/kg bw1) can be fatal in adults, and doses of 2 grams (± 0.2 g/kg bw1) in children. But also multiple cases are described surviving intakes ranging from 40 g (± 666 mg/kg bw[1]) to even 150-200 grams (± 2.50-3.33 g/kg bw1). Which is likely related to the possibility of dialysis treatment in case of renal failure after 1960s. There are no fatalities reported in recent years. The primary concern for acute chlorate exposure is oxidative damage to red blood cells. Despite low acute toxicity in animals, human experience indicates that classification of sodium chlorate as harmful is justified.There are no concerns related to dermal and inhalatory exposures,besides of hazards of ignition of dried sodium chlorate on clothing. This is supported by a report by the French poison control center that concludes: if one considers that 50% methemoglobinemia starts to induce signs that may lead to death in the absence of treatment, the dose would be about 20 g / kg for the whole population and 4.5 g / kg for the most sensitive part is the same range as rats.





[1]Estimated intakes per kg bw were calculated with adefault body weight assumption of 60 kg for adults, 10 kg for children and 5 kg for infants (WHO 2004).


 



Justification for classification or non-classification

Harmonized classification:


Sodium chlorate has a harmonised classification (index No. 017-005-00-9, ATP0) as Acute Tox. 4 *, H302 (* minimum classification for the category).


However, an intention for a revised CLH has been submitted to Sweden on 24/06/2019 with Acute Tox. 3 , H301: https://echa.europa.eu/fr/registry-of-clh-intentions-until-outcome/-/dislist/details/0b0236e183552bed.


Self classification:


Acute toxicity (Oral):


Under the test conditions, the oral LD50 of the test substance is > 5000 mg/kg bw in rats. Despite the low acute toxicity in animals, sodium chlorate has an harmonised classification (index No. 017-005-00-9, ATP0) as Acute Tox. 4 *, H302 (* minimum classification for the category) based on human experience indicating that classification of sodium chlorate is justified.


Acute toxicity (Dermal):


Results from acute dermal and inhalation studies show that sodium chlorate does not require classification.


Under the test conditions, the dermal LD50 of the test item is considered to exceed 2000 mg/kg body weight, in both male and female rats. Therefore, the test item is not classified according to the Regulation (EC) N° 1272-2008 and according to the GHS. No signal word or hazard statement is required.


Acute toxicity (Inhalation):


Results from acute dermal and inhalation studies show that sodium chlorate does not require classification.


Under the test conditions, the inhalation LC50 of the test item is considered to exceed 5000 mg/m3 in both male and female rats. Therefore, the test item is not classified according to the Regulation (EC) N° 1272-2008 and according to the GHS. No signal word or hazard statement is required.