Potassium chromate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

17/1/1983-23/2/1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline-comparable proprietary study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

no

Remarks:

Pre-dates GLP

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium chromate

EC Number:

231-889-5

EC Name:

Sodium chromate

Cas Number:

7775-11-3

Molecular formula:

CrH2O4.2Na

IUPAC Name:

disodium dioxido(dioxo)chromium

Constituent 2

Reference substance name:

Sodium dichromate

EC Number:

234-190-3

EC Name:

Sodium dichromate

Cas Number:

10588-01-9

Molecular formula:

Cr2Na2O7

IUPAC Name:

sodium dichromate

Constituent 3

Reference substance name:

Potassium dichromate

EC Number:

231-906-6

EC Name:

Potassium dichromate

Cas Number:

7778-50-9

Molecular formula:

Cr2H2O7.2K

IUPAC Name:

sodium dichromate

Details on test material:

Sodium chromate: yellow powder
Sodium dichromae: orange/red powder
Potassium dichromate: orange/red powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, UK
- Age at study initiation: 7-9 weeks
- Weight at study initiation: Not detailed
- Fasting period before study: 18h
- Housing: Individual
- Diet: ad libitum except pre-dosing period
- Water: ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-21
- Humidity (%): 24*-74
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 5% w/v
- Amount of vehicle (if gavage): variable
- Justification for choice of vehicle: solubility of test material
- Lot/batch no. (if required): -
- Purity: :

Doses:

Sodium chromate: 0.2, 0.5, 1.5, 3.0, 5.0 ml/kg; equivalent to 10, 25, 75, 150 and 250 mg/kg bw
Sodium dichromate: 0.2, 0.5, 1.5, 3.0 and 5.0 ml/kg; equivalent to 10, 25, 75, 150 and 250 mg/kg bw
Potassium dichromate: 0.5, 1.0, 2.0, 4.0 and 6.0 ml/kg; equivalent to 25, 50, 100, 200 and 300 mg/kg bw

No. of animals per sex per dose:

Five/sex

Control animals:

yes

Details on study design:

Animals were administered a single gavage dose and observed for 14 days. Rats were weighed on Days 1, 4, 7, 11 and 14. Gross necropsy was performed on all animals, weights of the brain, lungs, liver, spleen, kidneys and gonads were recorded.

Statistics:

Homogeneity of variance was establised using the F-max test, follwoed by Student;s t-test or Wilcoxon Rank Sum test.

Results and discussion

Preliminary study:

Dose levels of 0.2, 1.0, 2.0, 4.0 and 6.0 ml/kg bw were used for each compound; equivalent to 10, 50, 100, 200 and 300 mg/kg bw. Deaths occurred at >=100 mg/kg bw (sodium chromate), at >=200 mg/kg bw (sodium dichromate) and at >= 200 mg/kg bw (potassium dichromate).

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

129.5 mg/kg bw

95% CL:

118.5 - 142

Remarks on result:

other: Sodium chromate

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

67 mg/kg bw

95% CL:

58.5 - 77

Remarks on result:

other: Sodium chromate

Effect levels 3

Sex:

male

Dose descriptor:

LD50

Effect level:

123.5 mg/kg bw

95% CL:

107 - 142.5

Remarks on result:

other: Sodium dichromate

Effect levels 4

Sex:

female

Dose descriptor:

LD50

Effect level:

86.5 mg/kg bw

95% CL:

74 - 101

Remarks on result:

other: Sodium dichromate

Effect levels 5

Sex:

male

Dose descriptor:

LD50

Effect level:

168 mg/kg bw

95% CL:

154.5 - 182.5

Remarks on result:

other: Potassium dichromate

Effect levels 6

Sex:

female

Dose descriptor:

LD50

Effect level:

90.5 mg/kg bw

95% CL:

81.5 - 100.5

Remarks on result:

other: Potassium dichromate

Mortality:

Sodium chromate:
In the main study, mortality occurred at dose levels of >=75 mg/kg bw (females) and >=150 mg/kg bw (males) within one day of dosing.
Sodium dichromate:
In the main study, mortality occurred at dose levels of >=75 mg/kg bw (females) and >=150 mg/kg bw (males) within two days of dosing
Potassium dichromate:
In the main study, mortality occurred at dose levels of >=100 mg/kg bw (females) and >=200 mg/kg bw (males) within one day of dosing

Clinical signs:

other: Sodium chromate: piloerection, tremors, hyperkinesia, sedation, hunched posture, ataxia, diarrhoea, coma (30 minutes - 6 days) Sodium dichromate: piloerection, hypothermia, hunched posture, hyperkinesia, hypokinesia, prostration, ataxia, diarrhoea, sedati

Gross pathology:

Sodium chromate: reddened gastric mucosa with abnormal (green) coloring and contents; green areas on lungs
Sodium dichromate: reddened gastric mucosa with abnormal (green) coloring and contents; green areas on lungs
Potassium dichromate: distended and reddened gastric mucosa with abnormal (green) coloring; green areas on lungs

Other findings:

Organ weights were unaffected by treatment with any compound

Any other information on results incl. tables

Dose level		Mortality
		Sodium chromate		Sodium dichromate		Potassium dichromate
ml/kg bw	mg/kg bw	M	F	M	F	M	F
6.0	0 (controls)	0	0	0	0	0	0
0.2	10	0	0	0	0	-	-
0.5	25	0	0	0	0	0	0
1.0	50	-	-	-	-	0	0
1.5	75	0	1	0	1	-	-
2.0	100	-	-	-	-	0	4
3.0	150	4	5	5	4	-	-
4.0	200	-	-	-	-	4	5
5.0	250	5	5	4	5	-	-
6.0	300	-	-	-	-	5	5

Applicant's summary and conclusion

Interpretation of results:

toxic

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The results of this study indicate that sodium chromate, sodium dichromate and potassium dichromate are classified as (R25) 'Toxic if swallowed' according to EU criteria.

Executive summary:

Groups of rats (5/sex) were gavaged with single doses of sodium chromate, sodium dichromate or potassium dichromate (in water) at dose levels of between 10 and 300 mg/kg bw. Animals were observed for 14 days. Bodyweights were recorded on Days 1, 4, 7, 11 and 14. Gross necropsy was performed on all animals and organ weights recorded.

Deaths occurred at dose levels of >=75 mg/kg bw (sodium chromate, sodium, dichromate) and at >=100 mg/kg bw (potassium dichromate): females were slightly more sensitive than males for all compounds. Signs of toxicity were observed in all groups and included hunched posture, tremors, hypokinesia, sedation, prostration, coma, piloerection, ataxia, diarrhoea, dacryorrhoea and hyperkinesia. Slightly reduced weight gain was seen in some surviving animals. Findings at necropsy were limited to reddening and staining of the stomach, abnormal gastric contents and green staining of the lungs. Organ weights were unaffected by treatment.

LD 50 values were calculated to be:

Sodium chromate: 129.5 (118.5 -142.0) mg/kg bw in males; 67.0 (58.5 -77.0) mg/kg bw in females

Sodium dichromate: 123.5 (107.0 -142.5) mg/kg bw in males; 86.5 (74.0 -101.0) mg/kg bw in females

Potassium dichromate: 168.0 (154.5 -182.5) mg/kg bw in males; 90.5 (81.5 -100.5) mg/kg bw in females