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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reference
Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
No guideline study (conducted before OECD guidelines became available); sufficient information availble on materials and methods; limited no. of parameters evaluated; results described in the text, tables and figures.
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
no guideline followed
Principles of method if other than guideline:
Chromium oxide green was tested in BD rats for toxicity (90 day test) and for long-term toxicity and carcinogenicity (see IUCLID section 7.7). The dose levels used were 2 % and 5 % in diet.
GLP compliance:
no
Limit test:
no
Species:
rat
Strain:
other: BD (inbred)
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: about 100 days old
- Weight at study initiation: average of about 200 g
- Housing: The animals were housed in groups of four in Makrolon cages.
- Diet: Untreated control animals were fed Altromin, while the test pigment was administered in bread, which was made twice weekly.
- Water: ad libitum; tap water
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
DIET PREPARATION
- The Test pigment was administered in bread, which was made twice weekly by incorporating 1, 2 or 5% Cr2O3 into a dough made from 2835 g flour, 150 milk powder, 150 g mixed salts (Nacl, CaHPO4 and Cu, Zn, Co, Mn and K), 150 g cooking oil, 150 g cod-liver oil, 300 g malt extract, 600 g sugar, 80 g yeast and 900 ml water and subsequently baked.
- Uneaten bread was weighed in order to determined the amount consumed.
- At weekends the exposed groups received the control diet with vegetable supplement.
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
no data
Duration of treatment / exposure:
90 days
Frequency of treatment:
5 days/week
Dose / conc.:
2 other: % nominal in diet
Dose / conc.:
5 other: % nominal in diet
No. of animals per sex per dose:
14 males and five females (2 % group)
5 males and 10 females (5 % group)
6 males and 6 females (control group)
Control animals:
yes
Details on study design:
No details stated.
Positive control:
no data
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: fortnightly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes, weekly
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: Yes, bloodpicture was determined before the beginning of the experiment and monthly during the feeding. At the end of the feeding period blood samples were taken from the tail vein for counts of erythrocytes and total and specific types of leucocytes and for haemoglobin estimations.
- Anaesthetic used for blood collection: No data
- Animals fasted: Yes, at the end of the feeding period for 24 hours.
- How many animals: 6 males and 6 females (control), 14 males and 5 femals from the 2 % group, 4 males and 10 females from the 5 % group

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At the end of the feeding period blood samples were taken from the retrobulbar plexus
- Animals fasted: Yes, at the end of the feeding period for 24 hours.
- How many animals: 10 controls, 13 males and 4 females from the 2 % group, 4 males and 7 females from the 5 % group
- Parameters checked: blood sugar, serum protein and serum bilirubin

URINALYSIS: Yes
- Time schedule for collection of urine: random samples were taken during the course of the study and from all animals in the last week of the experiment
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data
- Parameters checked: protein, sugar, bilirubin, blood and sediment

NEUROBEHAVIOURAL EXAMINATION: No data
Sacrifice and pathology:
The animals were killed within 1 wk of the cessation of Cr2O3 feeding with ether and autopsied.
GROSS PATHOLOGY: Yes: organ weights (liver, spleen, kidney) in all animals and brain and ovaries in random samples; gross pathology conducted
HISTOPATHOLOGY: Yes: Samples of liver, spleen, kidney, brain, ovaries, lung, heart, stomach, small intestine and urinary bladder were fixed in 4 % bufffered formalin and sections were embedded in paraffin wax and stained with haematoxylin and eosin.
Other examinations:
During the last 30 days of treatment, males and females from the same group were paired to test fertility, and the number of young in each litter was recorded (see IUCLID section 7.8.1, s_Ivankovic_1975).
Statistics:
no data
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not specified
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Neuropathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
not specified
Other effects:
not specified
Details on results:
CLINICAL SIGNS AND MORTALITY
- Administration of 2% (total amount Cr2O3 consumed M/F: 75/72 g/kg bw) or 5% (total amount Cr2O3 consumed M/F: 180/160 g/kg bw) of chromium oxide green via the diet to rats for 90 days did not produce signs of toxicity and no detectable differences from untreated controls.
- One male rat fed the 5% Cr2O3 diet died 70 days after the start of the experiment from acute pneumonia.

BODY WEIGHT AND WEIGHT GAIN
- No significant difference in body weight were evident between the two experimental groups and the controls.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
- Food intake was normal throughout the study, averaging 20 g/day for males and 15 g/day for females.
- The total amount of Cr2O3 consumed during the whole of the experiment in which 2% was fed was 75 g/kg body weight (25 g/ animal) for males and 72 g/kg body weight (18 g/ animal) for females.
- In the experiment in which 5% was fed, 180 g/kg was consumed by males and 160 g/kg by females.

HAEMATOLOGY
- Haemoglobin determinations and counts of erythrocytes and total and differential leucocytes in blood samples from the Cr2O3-treated groups showed no significant deviations from the corresponding control values

CLINICAL CHEMISTRY
- there were no adverse findings in determinations of serum protein, serum bilirubin and blood sugar

URINALYSIS
- Urine analyses carried out during the expriment and at termination showed no significant differences between the treated and the control animals

ORGAN WEIGHTS
- With the exception of the weights of the spleen and liver, which showed some reduction in the treated animals, there were no macroscopic or histological changes.
- the reduced weights of liver and spleen could not be evaluated as a serious toxic effect without further investigation. This interpretation is supported by the result of the long-term feeding-study, where concentrations of 1, 2 and 5% Cr2O3 in the feed over a period of 2 yr were tolerated without signs of chronic toxicity.

GROSS PATHOLOGY
- no macroscopic changes

HISTOPATHOLOGY: NON-NEOPLASTIC
- Compared with sections of organs from control animals, no changes could be detected that could be attributed to the Cr2O3 treatment.

OTHER FINDINGS
- The faeces of the treated animals showed an intense green colouration throughout the study, indicating significant excretion of the administered pigment.

No further details stated.
Dose descriptor:
NOAEL
Effect level:
> 2 800 mg/kg bw/day (actual dose received)
Based on:
other: 5% dietary Cr2O3 in feed
Sex:
male/female
Basis for effect level:
other: no systemic toxicity could be observed
Critical effects observed:
not specified
Conclusions:
Administration of 2% (total amount Cr2O3 consumed M/F: 75/72 g/kg bw) or 5% (total amount Cr2O3 consumed M/F: 180/160 g/kg bw) of chromium oxide green via the diet to rats for 90 days did not produce signs of toxicity and no detectable differences from untreated controls.
Reason / purpose for cross-reference:
reference to same study
Reference
Endpoint:
fertility, other
Remarks:
based on a 90 day repeated dose oral toxicity
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
no data available
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Fertility screening study as part of the 90-day toxicity study; only a limited no of animals were paired; results not presented in detail (only summary). Can be used as supportive information.
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
no guideline followed
Principles of method if other than guideline:
fertility screening study as part of the 90-day toxicity study
GLP compliance:
no
Limit test:
no
Species:
rat
Strain:
other: inbred BD
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: about 100 days old
- Weight at study initiation: about 200 g
- Housing: The animals were housed in groups of four in Makrolon cages.
- Diet: Untreated control animals were fed Altromin, while the test pigment was administered in bread, which was made twice weekly.
- Water: ad libitum; tap water
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): The Test pigment was administered in bread, which was made twice weekly by incorporating 1, 2 or 5% Cr2O3 into a dough made from 2835 g flour, 150 milk powder, 150 g mixed salts (Nacl, CaHPO4 and Cu, Zn, Co, Mn and K), 150 g cooking oil, 150 g cod-liver oil, 300 g malt extract, 600 g sugar, 80 g yeast and 900 ml water and subsequently baked.
Details on mating procedure:
During the last 30 days of treatment, males and females from the same group were paired to test fertility.
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
no data
Duration of treatment / exposure:
90 days
Frequency of treatment:
5 days per week
Details on study schedule:
no data
Dose / conc.:
2 other: % nominal in diet
Dose / conc.:
5 other: % nominal in diet
No. of animals per sex per dose:
Group 1: 14 males and 5 females
Group 2: 5 males and 10 females
Control group: 6 males and 6 females
Control animals:
yes
Details on study design:
Uneaten bread was weighed in order to determine the amount consumed. There were only small losses from crumbs.
Positive control:
No positive control substance was tested.
Parental animals: Observations and examinations:
BODY WEIGHT: Yes
- Time schedule for examinations: Body weight was determined fortnightly.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Time schedule for examinations: Uptake of food was determined weekly.

OTHER:
The blood picture was determined before the beginning of the experiment and monthly during the feeding. Random samples were taken during the course of the study and from all animals in the last week of the experiment for urinary determinations of protein, sugar, bilirubin, blood and sediment.

At the end of the feeding period, the animals were fasted for 24 hours. Blood samples were taken from the retrobulbar plexus for determinations of blood sugar, serum protein and serum bilirubin and from the tail vein for counts of erythrocytes and total and specific types of leucocytes and for haemoglobin estimations.
Oestrous cyclicity (parental animals):
no data
Sperm parameters (parental animals):
no data
Litter observations:
The number of young in each litter was recorded.
Postmortem examinations (parental animals):
The animals were killed with ether and autopsied, the liver, spleen and kidney being weighed in all animals and the brain and ovaries in random samples. Samples of these organs and of the lung, heart, pancreas, stomach, small intestine and urinary bladder were fixed in 4% buffered formaline and sections were embedded in paraffin wax and stained with haematoxylin and eosin.
Postmortem examinations (offspring):
no data
Statistics:
no data
Reproductive indices:
no data
Offspring viability indices:
no data
Clinical signs:
effects observed, treatment-related
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Other effects:
no effects observed
Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed
CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
The treatment was well tolerated at both dose levels. One male rat fed the 5% Cr2O3 diet died 70 days after the start of the experiment from acute pneumonia.

BODY WEIGHT AND FOOD CONSUMPTION AND TEST SUBSTANCE INTAKE (PARENTAL ANIMALS)
Food intake was normal throughout the study, averaging 20 g/day for males and 15 g/day for females. The total amount of Cr2O3 consumed during the whole of the experiment in which 2% was fed was 75 g/kg body weight for males and 72 g/kg body weight for females. In the experiment in which 5% was fed, 180 g/kg was consumed by males and 160 g/kg by females.
No significant difference in body weight were evident between the two experimental groups and the controls.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
Altogether 9 females were paired with males from the same dosage group 60 days after the start of feeding. All the females became pregnant in due course, the gestation period was normal (23 days) and the young showed no malformations or other adverse effects. Litter sizes were in the normal range, averaging 8 pups.

GROSS PATHOLOGY (PARENTAL ANIMALS)
With the exception of the weights of the spleen and liver, which showed some reduction in the treated animals, there were no macroscopic or histological changes.

HISTOPATHOLOGY (PARENTAL ANIMALS)
Compared with sections of organs from control animals, no changes could be detected that could be attributed to the Cr2O3 treatment.

OTHER FINDINGS (PARENTAL ANIMALS)
The faeces of the treated animals showed an intense green colouration throughout the study, indicating significant excretion of the administered pigment.
Haemoglobin determinations and counts of erythrocytes and total and differential leucocytes in blood samples from the Cr2O3-treated groups showed no significant deviations from the corresponding control values, and there were no adverse findings in determinations of serum protein, serum bilirubin and blood sugar.
Urine analyses carried out during the expriment and at termination showed no significant differences between the treated and the control animals.
Dose descriptor:
NOAEL
Remarks on result:
not determinable
Remarks:
no NOAEL identified Generation not specified (migrated information)
Clinical signs:
not specified
Mortality / viability:
no mortality observed
Body weight and weight changes:
not specified
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings:
not specified
VIABILITY (OFFSPRING)
The young showed no malformations or other adverse effects. Litter sizes were in the normal range, averaging 8 pups.

OTHER FINDINGS (OFFSPRING)
Some of the progeny were retained for lifetime observation and so far (600 days) no tumours have been detected.
Reproductive effects observed:
not specified

Fertility was not affected and gestation periods were normal. Offspring showed no adveres effect or external malformations and litter size was in the normal range.

Conclusions:
Fertility was not affected and gestation periods were normal. Offspring showed no adveres effect or external malformations and litter size was in the normal range.
Reason / purpose for cross-reference:
reference to same study
Reference
Endpoint:
carcinogenicity: oral
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
No guideline study (conducted before OECD guidelines became available); sufficient information available on materials and methods; results not presented in detail (only summarised in the text, no tables, figures or info on statistics.
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
no guideline followed
Principles of method if other than guideline:
The pigment chromic oxide (Cr2O3), was tested in BD rats for carcinogenicity (2-year study). The rats were given 1, 2 or 5 % Cr2O3 in feed on 5 days/week for 2 years.
GLP compliance:
not specified
Species:
rat
Strain:
other: BD (inbred)
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: about 100 days old
- Weight at study initiation: average of about 200 g
- Housing: The animals were housed in groups of four in Makrolon cages.
- Diet: Untreated control animals were fed Altromin®, while the test pigment was administered in bread, which was made twice weekly.
- Water (ad libitum): tap water
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
DIET PREPARATION
The test pigment was administered in bread, which was made twice weekly by incorporating Cr2O3 into a dough made from 2835 g flour, 150 g milk powder, 150 g mixed salts (NaCl, CaHPO4 and Cu, Zn, Co, Mn and K), 150 g cooking oil, 150 g cod-iver oil, 300 g malt extract, 600 g sugar, 80 g yeast and 900 ml water and subsequently baked..
- Uneaten bread was weighed in order to determine the amount consumed
- Each weekend the test animals were fed a control diet with a vegetable supplement.
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
No Data
Duration of treatment / exposure:
2 years
Frequency of treatment:
5 days/week (600 feeding days)
Post exposure period:
At the end of the feeding period, surviving animals were maintained on the control diet until they died or became moribund, death being induced with ether in the latter case.
Dose / conc.:
1 other: % Cr2O3 in bread (m/f)(nominal)
Dose / conc.:
2 other: % Cr2O3 in bread (m/f)(nominal)
Dose / conc.:
5 other: % Cr2O3 in bread (m/f)(nominal)
No. of animals per sex per dose:
60 male and female rats (test groups receiving test item)
60 male and female rats (control group)
Control animals:
yes, concurrent no treatment
Positive control:
No data
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
Survival of animals was determined.

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Monthly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Intake of the test pigment was calculated weekly
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data
- Compound intake calculated : Yes

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
-
OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: No data

CLINICAL CHEMISTRY:No data

URINALYSIS: No data

NEUROBEHAVIOURAL EXAMINATION: No data
Sacrifice and pathology:
At autopsy, all the important organs, icluding the brain and nervous system, were fixed in 4 % formalin solution and studied histologically.
Statistics:
No data
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
not specified
Clinical biochemistry findings:
not specified
Urinalysis findings:
not specified
Behaviour (functional findings):
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
no effects observed
Neuropathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Other effects:
not specified
Details on results:
CLINICAL SIGNS AND MORTALITY
The investigation of the pigment Cr2O3 (C-green 9) showed no toxic effects in BD rats given high oral doses over 2 years.
Feeding of 1 % (total dose consumed: 360 g/kg bw), 2 % (total dose consumed: 720 g/kg bw) or 5 % (total dose consumed: 1800 g/kg bw) Cr2O3 via the diet for 2 years was well tolerated by male and female rats.
The 60 control rats reached an average life expectancy of 890 +45 /-30 days.
Of the 60 rats given 1 % Cr2O3, the first died from a lung infection after 130 days and the last 1315 days from the start of the experiment. The average life expectancy was 870 +30/-15 days.
The first death in the group given 2% Cr2O3 occurred after 127 days and the last 1230 days from the start of feeding. The average survival period was 880 +30/-20 days.
In the group given 5 % Cr2O3, the first rat died after 113 days and the last after 1295 days. The average survival was 860 +40/-25 days.
The median survival times in all three dosage groups were comparable with that of the controls.

BODY WEIGHT AND WEIGHT GAIN
The body weight curves for the treated animals did not differ from those for the controls.

GROSS PATHOLOGY
No macroscopic post-mortem findings could be causally related to the Cr2O3 treatment.

HISTOPATHOLOGY: NON-NEOPLASTIC
No histological post-mortem findings could be causally related to the Cr2O3 treatment.

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
No histological post-mortem findings could be causally related to the Cr2O3 treatment.
Control rats: Two mammary fibroadenomas, one mammary carcinoma and two hypophyseal adenomas were observed in this group.
1 % Cr2O3 dosed rats: Only three mammary fibroadenomas were detected in this group. The remaining animals showed no macroscopic or microscopic signs of benign or malignant growths.
2 % Cr2O3 dosed rats: One mammary fibroadenoma was the only tumour observed.
5 % Cr2O3 dosed rats: Three mammary fibroadenomas and one hypophyseal adenoma were found, but no other benign or malignant tumours appeared.
Relevance of carcinogenic effects / potential:
Animals observed during their entire life did not show any reduction of the average life expectancy, and no carcinogenic action related to treatment was detected.
Dose descriptor:
NOAEL
Effect level:
> 3 000 mg/kg bw/day
Based on:
other: 5% dietary of Cr2O3 in feed
Sex:
male/female
Remarks on result:
other: Animals observed during their entire life did not show any reduction of the average life expectancy, and no carcinogenic action related to treatment was detected.
Conclusions:
Animals observed during their entire life did not show any reduction of the average life expectancy, and no carcinogenic action related to treatment was detected.
Executive summary:

Animals observed during their entire life did not show any reduction of the average life expectancy, and no carcinogenic action related to treatment was detected.

Data source

Reference
Reference Type:
publication
Title:
Absence of toxic and carcinogenic effects after administration of high doses of chromic oxide pigment in subacute and long-term feeding experiments in rats.
Author:
Ivankovic, S. and R. Preussman
Year:
1975
Bibliographic source:
Food Cosmet Toxicol.13(3): 347-51.

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
other: no guideline followed
GLP compliance:
not specified
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Chromium (III) oxide
EC Number:
215-160-9
EC Name:
Chromium (III) oxide
Cas Number:
1308-38-9
Molecular formula:
Cr2O3
IUPAC Name:
chromium (III) oxide
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material (as cited in study report): Chromium oxide green (Schultz no. 1451; Colour Inddex no. 77288; pigment green 17)
- Physical state: Fine green powder

Test animals

Species:
rat
Strain:
other: inbred BD
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: about 100 days old
- Weight at study initiation: about 200 g
- Housing: The animals were housed in groups of four in Makrolon cages.
- Diet: Untreated control animals were fed Altromin, while the test pigment was administered in bread, which was made twice weekly.
- Water: ad libitum; tap water

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): The Test pigment was administered in bread, which was made twice weekly by incorporating 1, 2 or 5% Cr2O3 into a dough made from 2835 g flour, 150 milk powder, 150 g mixed salts (Nacl, CaHPO4 and Cu, Zn, Co, Mn and K), 150 g cooking oil, 150 g cod-liver oil, 300 g malt extract, 600 g sugar, 80 g yeast and 900 ml water and subsequently baked.
Analytical verification of doses or concentrations:
not specified
Details on mating procedure:
During the last 30 days of treatment, males and females from the same group were paired.
Duration of treatment / exposure:
90 days
Frequency of treatment:
5 days per week
Doses / concentrationsopen allclose all
Dose / conc.:
2 other: % nominal in diet
Dose / conc.:
5 other: % nominal in diet
No. of animals per sex per dose:
Group 1: 14 males and 5 females
Group 2: 5 males and 10 females
Control group: 6 males and 6 females
Control animals:
yes
Details on study design:
Uneaten bread was weighed in order to determine the amount consumed. There were only small losses from crumbs.

Examinations

Maternal examinations:
Body weight was determined fortnightly and food consumption was recorded weekly. The blood picture was determined before the beginning of the experiment and monthly during the feeding. Random samples were taken during the course of the study and from all animals in the last week of the experiment for urinary determinations of protein, sugar, bilirubin, blood and sediment.
The animals were killed with ether and autopsied, the liver, spleen and kidney being weighed in all animals and the brain and ovaries in random samples. Samples of these organs and of the lung, heart, pancreas, stomach, small intestine and urinary bladder were fixed in 4% buffered formaline and sections were embedded in paraffin wax and stained with haematoxylin and eosin.

At the end of the feeding period, the animals were fasted for 24 hours. Blood samples were taken from the retrobulbar plexus for determinations of blood sugar, serum protein and serum bilirubin and from the tail vein for counts of erythrocytes and total and specific types of leucocytes and for haemoglobin estimations.
The number of young in each litter was recorded.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Mortality:
mortality observed, non-treatment-related
Description (incidence):
One male rat fed the 5% Cr2O3 diet died 70 days after the start of the experiment from acute pneumonia.
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Other effects:
no effects observed

Maternal developmental toxicity

Changes in pregnancy duration:
no effects observed
Description (incidence and severity):
The gestation period was normal (23 days).
Changes in number of pregnant:
no effects observed
Description (incidence and severity):
All the females became pregnant in due course.
Details on maternal toxic effects:
CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
The treatment was well tolerated at both dose levels.

BODY WEIGHT AND FOOD CONSUMPTION AND TEST SUBSTANCE INTAKE (PARENTAL ANIMALS)
Food intake was normal throughout the study, averaging 20 g/day for males and 15 g/day for females. The total amount of Cr2O3 consumed during the whole of the experiment in which 2% was fed was 75 g/kg body weight for males and 72 g/kg body weight for females. In the experiment in which 5% was fed, 180 g/kg was consumed by males and 160 g/kg by females.
No significant difference in body weight were evident between the two experimental groups and the controls.
GROSS PATHOLOGY (PARENTAL ANIMALS)
With the exception of the weights of the spleen and liver, which showed some reduction in the treated animals, there were no macroscopic or histological changes.

HISTOPATHOLOGY (PARENTAL ANIMALS)
Compared with sections of organs from control animals, no changes could be detected that could be attributed to the Cr2O3 treatment.

OTHER FINDINGS (PARENTAL ANIMALS)
The faeces of the treated animals showed an intense green colouration throughout the study, indicating significant excretion of the administered pigment.
Haemoglobin determinations and counts of erythrocytes and total and differential leucocytes in blood samples from the Cr2O3-treated groups showed no significant deviations from the corresponding control values, and there were no adverse findings in determinations of serum protein, serum bilirubin and blood sugar.
Urine analyses carried out during the expriment and at termination showed no significant differences between the treated and the control animals.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
> 3 other: %
Based on:
test mat.
Basis for effect level:
other: no effects observed

Results (fetuses)

Changes in litter size and weights:
no effects observed
Description (incidence and severity):
Litter sizes were in the normal range, averaging 8 pups.
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Details on embryotoxic / teratogenic effects:
Young showed no malformations or other adverse effects. Some of the progeny were retained for lifetime observation and so far (600 days) no tumours have been detected.

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
> 3 other: %
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no effects observed

Overall developmental toxicity

Developmental effects observed:
no

Applicant's summary and conclusion

Conclusions:
As part of a 90-day feeding study developmental toxicity/teratogenicity parameters were evaluated. Females and males exposed to ferric chloride for 60 days were paired. At the end of the dosing period no effects on maternal body weight and food consumption were noted. Haematology parameters were comparedable to control animals. All females became pregnant in due course, the gestation period was normal (23 days) and the young showed no malformations or other adverse effects. Litter sizes were in the normal range (8 pups).