Semicarbazide hydrochloride

Carcinogenicity

Description of key information

Key study: Test substance Semicarbazide Hydrochloride is not carcinogenic in rats, Wistar Hannover GALAS and NOAEL was judged to be 0.6 mg/kg/bw (10 ppm) for males and 3.9 mg/kg/bw (50 ppm) for females.

Key study: The administration of  0.0625 %  test substance in drinking water induced Lung tumour and Blood vessel tumour in tested animals.

Supporting study: Semicarbazide hydrochloride gave negative results to Swiss Albino mice, through administered at sufficiently high dose levels to cause toxic effects in both sexes of Charles River CD rats.

Supporting study: In another study, test substance induced pulmonary tumors in dd mice. Incidence of tumors was 75% with average of 1.0 nodules per mouse.

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

No GLP.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: 4 weeks, at room temperature and 8 weeks at 4ºC.
- Stability under test conditions:Yes

Species:

rat

Strain:

Wistar

Remarks:

Hannover GALAS

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:CLEA Japan, Inc. (Tokyo, Japan)
- Age at study initiation: 5 weeks old
- Housing: 2-3 per plastic cage with sterilized softwood chips as bedding in a barrier-maintened animal room.
- Diet (e.g. ad libitum): a basal diet (CE-2, CLEA Japan, Inc.)
- Water (e.g. ad libitum): ad libitum
- Acclimation period:1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C):24+-1
- Humidity (%):55+-5
- Photoperiod (hrs dark / hrs light):12-h light/dark

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): every 4 weeks, stored at 4ºC

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Stability of SEM-HCL was prepared by Japan Food Research Laboratories (Osaka, Japan). For each dose, test copund retained 69-100% purity (average= 87%) after sotrage at room temperature for 4 weeks or 82-100% (average=94%) after storage at 4ºC for up to 8 weeks. SEM was not detected in the basal diet (detection limit =0.01 ppm)

Duration of treatment / exposure:

104 weeks

Frequency of treatment:

Daily

Dose / conc.:

0 ppm

Remarks:

Control

Dose / conc.:

10 ppm

Dose / conc.:

50 ppm

Dose / conc.:

250 ppm

No. of animals per sex per dose:

Four groups, each containing 50 males and 50 females

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: Based on the previous study (90-day toxcicity study of semicarbazide hydrochloride in wistar Hannover GALATS rats), the highest dose was selected as 250 ppm because of no effects to body growth.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes, mortality

DETAILED CLINICAL OBSERVATIONS: Yes (thorax, Enlargement and deformation of the knee joint)

BODY WEIGHT: Yes (every week)

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes, recorded every week until week 13 and every 4 weeks thereafter.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data

OPHTHALMOSCOPIC EXAMINATION:No

HAEMATOLOGY: Yes (eukocyte, white blood cells)
- Anaesthetic used for blood collection: Yes (identity) -for hematology and serum biochemistry.

CLINICAL CHEMISTRY: Yes (Cl and glucose, AST, ALT, K)

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes (palpation of the joints of limbs)

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, pituitary, eyes, Harderian glands, spinal cord (cervical, thoracic, and lumbar portions together with corresponding vertebral bones), salivary glands, stomach, small intestine (duodenum, jejunum, and ileum), large intestine (cecum, colon, and rectum), pancreas, urinary bladder, skin, mammary gland, mesenteric lymph nodes, thoracic aorta, trachea, esophagus, thyroid glands, tongue, thigh muscle, sciatic nerve, epididymides, seminal vesicles, prostate, uterus, vagina, and macroscopic lesions were removed. All organs were fixed in 10% buffered formalin, except for testes, which were fixed in Bouin’s solution overnight
Organ weights: Yes, Absolutive and relative organ weights - the brain, heart, lungs, liver, spleen, adrenals, kidneys, testes, and ovaries.


HISTOPATHOLOGY: Yes, For examination of osteochondral lesions, the nasal cavity, sternum, right femur, right tibia, left knee joint, and spine (transverse sections of the cervical, thoracic, and lumbar vertebrae and a vertical section of the thoracic vertebrae) were fixed in 10% buffered formalin and then decalcified in EDTA solution at room temperature for a month. All tissues were routinely processed for paraffin embedding, sectioned, and stained with hematoxylin and eosin (HE).

Statistics:

Variance in data for body weights, food consumption, hematology, serum biochemistry, and organ weights was checked for homogeneity by Bartlett’s procedure. If the variance was homogeneous, the data were assessed by one-way analysis of variance. If not, the Kruskal–Wallis test was applied. When statistically significant differences were detected, the Dunnett’s multiple comparison test was employed for comparison between the control and treatment groups. Survival rates and the incidences of histopathological findings, including tumors, were compared using the Fisher’s exact test. The severity of the histopathological lesions observed in the chronic toxicity study was analyzed with the Mann–Whitney U-test.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Eenlargement of the knee joints was found in males and females at 250 ppm from week 24, and the severity was relatively higher in males than in females.At the end some of the animals had prominence of thorax.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Eight males and 7 females in the 0 ppm, p males and 10 females in 10 ppm, 17 males and 17 females in 50 ppm and 15 males and 13 females in the 250 ppm were found death or were euthanised when moribund.
As the main cause of moribundity and death, pituitary tumors were the most frequent tumor type in both sexes. Chronic nephropathy and mammary gland tumors were also common in males and females.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weights of males in the 250 ppm group was suppressed after 1 year of age and was significantly lower at weeks 76,88 and 96 compared with 0 ppm group. In females, increase of body weight was found in week 3 to 6 in the 10 ppm group, from week 4 to 13 in the 50 ppm group, and from week 3 to 40 in the 250 ppm group.
The changes of the body weight was within 5 % in most cases, 7.6% in few cases.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Males - food consumption was decreased at 250 ppm group from week 84. Females- no differences amoung the group with the exception of a significant increase from week 1 to 2 in the 10 ppm group. In the bith sexes, no significant variations were found in the mean values for food consumption/animal or /kg body weight.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not specified

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Relative weights of brain and testes were increased significally in males in the 250 ppm group. Females - no changes in organ weights were found.

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Focal hyperplasia of the anterior pituitary, retinal atrophy, aggregation of foamy cells in the lung, bile duct proliferation in the liver, and acinar cell atro- phy in the pancreas were frequently observed in males and females in the 0 and 250 ppm groups. Radiculoneuropathy, cata- racts, focal hyperplasia in the Harderian glands, fatty infiltration in the pancreas, focal hypertrophy of the adrenal cortex, and degeneration of the sciatic nerve were also common in both sexes. In males, focal fibrosis in the heart and chronic nephropa- thy were frequent. . In females, mineralization in the kidney, interstitial cell proliferatidiffuse. C-cell hyperplasia in the thyroid, angioectasis in the adrenals, and cystic endometrial hyperplasia in the uterus were common. In the ovary, increased interstitial glands, loss of corpora lutea, and cysts were relatively commonon in the ovary, increased milk secretion, and atypical hyperplasia in the mammary gland were frequently observed.Compared to the 0 ppm group, aggrega- tion of foamy cells in the lung was statistically decreased in females in the 250 ppm group. Focal hyperplasia of the osteo- chondral tissue was sporadically found in the femur, tibia, ster- num, vertebrae, and nasal cavity, and the incidence of focal hyperplasia tended to increase in males in the 250 ppm group. Some of these lesions were located adjacent to SEM-HCl-induced lesions, and others were found in the diaphysis and nasal cavity, which are less susceptible to SEM-HCl.

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Anterior lobe adenomas or carcinomas in the pituitary gland were frequently found in both sexes. Stromal polyps in the uterus and fibroadenomas in the mmamary glands were common in females. Various tumor were found sporadically in all groups: but no significant differences in the incidences or histological types of any tumors.

Other effects:

effects observed, treatment-related

Description (incidence and severity):

HISTOPATHOLOGICAL FINDINGS IN BONES, JOINTS AND AORTA:
Osteochondral lesions, age-related changes, such as disarrangement of epiphyseal chondrocytes, necrosis, and fibrosis, were more pronounced than in the chronic toxicity study. SEM-HCl induced lesions were frequent and severe in males and females in the 250 ppm group.In males in the 50 ppm group, increased disarrangement of chondro- cytes and increased connective tissues were found in the sternum in about half of the animals, although only mild changes were noted.

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 0.6 mg/kg bw/day

Based on:

test mat.

Sex:

male

Remarks on result:

other: 10 ppm

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 3.9 mg/kg bw/day

Based on:

test mat.

Sex:

female

Remarks on result:

other: 50.0 ppm

Conclusions:

Based on the histopathological findings, the NOAEL was judged to 0.6 mg/kg/bw (10 ppm) for males and 3.9 mg/kg/bw (50 ppm) for females. Semicarbazide hydrochloride is not carcinogenic to males and females rats.

Executive summary:

According the available data from the present study, carcinogenicity effects of Semicarbazide hydrochloride were examinated in the male/females rats from Japan. Chronic toxicity study combined with carcinogenic study was performed. In the carcinogenicity study 50 males and 50 females rats per group (total 4 groups) during 104 weeks were used. The rats were fed a powdered diet containing SEMI HCl in 0 (control), 10,50 and 250 ppm. Animals were checked daily for clinical signs of toxicity and mortality, for body weights and food consumption,hematology analysis and gross examination.Number of death and moribund animals was relatively high for males and females in group of 50 ppmin the carcinogenicity study. Reduced body weight were observed at 250 ppm from week 76 only in males. There were no significant intergroup differences in the incidences or types of any tumors.SEM-HClexerted no toxic effects on hematology, serum biochemistry, or organ weights. Disarrangement of the chondrocytes accompanied by increased connective tissues and degeneration of the articular cartilage were observed as adverse effects of SEM-HCl in males at 50ppm and above and in females at 250 ppm. Based on the histopathological findings, the no-observed-adverse-effect levels estimated from present study were 0.6 mg/kg/bw (10 ppm) for males and 3.9 mg/kg/bw (50 ppm) for females. SEM-HCl had no carcinogenic potential in male or female rats.

Reference 2

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

No GLP

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 451 (Carcinogenicity Studies)

Deviations:

no

GLP compliance:

no

Species:

mouse

Strain:

Swiss

Remarks:

Albino mice

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: colony
- Age at study initiation:6 weeks old
- Housing: In plastic cages with granullar cellulose bedding, separated according to sex in groups of ten.
- Diet (e.g. ad libitum): Wayne lab-blox diet in regular pellets (Alluied Mills, Inc., Chicago, Illinois)
- Water (e.g. ad libitum): Tap water, or solution ad libitum.

Route of administration:

oral: drinking water

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: Selected dose 0.0625 % of test substance was administrated in drinking water. Solutions were prepared thrice weekly.

Group 1: Test substance was dissolved in the drinking water as a 0.0625% solution and was given for the life span of 50 female and 50 male mice which were 6 weeks old (47 days) at the beginning of the experiment.
Untreated control group 2 : 100 female and 100 male mice were kept and observed from weaning time (5 weeks of age).

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

During their lifetimes.

Frequency of treatment:

Daily

Dose / conc.:

0.062 other: %

Dose / conc.:

0.25 other: %

Dose / conc.:

0.5 other: %

Dose / conc.:

1 other: %

No. of animals per sex per dose:

Group 1: 50 males and 50 females
Group 2 (untreated): 100 males and 100 females.

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: Toxicity study was carried out prior to the chronic experiment. Five dose levels of test substance, 1, 0.5, 0-25, 0.125, and 0.0625% were administered in the drinking water daily for 35 days to Swiss mice.The solution 0.0625 % was found to be suitable for the lifelong treatment taking into account 4 parameters (survival rates, body weights, chemical consumption figures and histological changes)

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes, mortality

DETAILED CLINICAL OBSERVATIONS: Yes (weekly intervals)

BODY WEIGHT: Yes (weekly intervals)

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes, thrice weekly. Amount of drinking water containing the test substance during the study was observed.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: No

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, All organs were examined macroscopically and were fixed in 10% buffered formalin.

HISTOPATHOLOGY: Yes (adenoma, adenocarcinomas). Findings were made on liver, spleen, kidney, bladder, thyroid, heart, pancreas, testis, brain, nasal turbinale and at least four lobes of the lungs of each mouse. Sections from these tissues were stained routinely with hematoxylin and eosin.

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Lifespan was reduced in treated males.

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

effects observed, treatment-related

Description (incidence and severity):

In the treated groups: The average daily consumption per animal of water containing test substance was 7.8 ml for a female and 5.3 ml for the males.
The average daily intake of test substance was 3.3 mg for a female and 4.8 mg for a male.

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Lung tumours: Of the treated females, 25 (50%) had 37 such neoplasms. (20 mice had 31 adenomas and 5 had six adenocarcinomas). The average death age was 89 weeks (first one was found at the 50th week and the last at the 111th week of age).
Of the treated males, 15 (30%) had 21 lung tumours. (11 mice had twelve adenomas, 3 had five adenocarcinomas and 1 had an adenoma and three adenocarcinomas). The average death was 75 weeks (first in the week 20 and last at 111th week)

Blood vessels tumors: Of the treated females, 9 (18%) has blood vessel tumors. (3 had angiosarcomas in livers, 2 had angiosarcomas in ovaries, 2 had angiomas in livers, 1 had angioma in lymph node). The average death was 92 weeks (first one at week 74 and las one at the week 107)
In the treated males, 3 (65) had lesions (2 had angiosarcomas in livers at the 64th and 87th weeks and 1 had angiosarcomas in liver and lungs at the 93th week age).

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Other types of tumour such as:Malignant lymphona, histiocytoma, Sarcoma of glandural stomach, Papilloma of forestomach, skin,esophagus, Hepatomas, Hibernoma, Malignant Lymphoma, Adenocarcinomas of brest, ovaries and duodenum , Adenoma of thyroid, Fibrosarcoma, Carcinoma of skin, Adrenocortical adenoma, Leiomyosarcoma.

Tumours in untreated groups:There was appaerence, that animals in untreated control groups had also some kinds of tumours. Malignant lymphomas were significally higher that in a treated group, but thi is due to the fact that Malignant lymphomas develop in older ages. Untreated control groups had bigger survival time.

Key result

Dose descriptor:

conc. level:

Effect level:

ca. 0.062 other: %

Based on:

test mat.

Sex:

male/female

Basis for effect level:

haematology

histopathology: neoplastic

Diagnostic criteria for Angiom : the several layers of proliferating endothelial cells. A lesion to be considered an angiosarcoma was composed of highly anaplastic endothelial cells forming vascular spaces and invading the surrounding tissues and sometimes giving metastases to other organs.

Diagnostic criteria for adenoma: The well demarcated, nodular lesion composed of proliferating neoplastic, alveolar cells type B, exhibiting adenoid structures. The cells were cuboidal or columnar with dark nuclei and acidophilic cytoplasms. In case of adenocarcinoma, the composing cells showed irregular growth pattern, they usually invaded the surrounding tissues including blood vessels and bronchi. The sizes and shapes of the cells varied, many mitosen were seen.

Conclusions:

The administration of 0.0625 % test substance in drinking water induced Lung tumour and Blood vessel tumour in tested animals.

Executive summary:

In the present study, the administration of 0.0625% carbamylhydrazine hydrochtoride in the drinking water was tested in 6-week-old Swiss albino mice during their lifes. This dose was selected based on the toxicity study made prior chronic study. The total consumption of water containing test substance was measured thwice weekly. Test substance in that doses enhanced the development of tumours of the lungs and blood vessels. As compared with the untreated controls, the incidence of lung tumors rose from 21 to 50% in the females and from 23 to 30% in the males, while the incidence of blood vessel tumours increased from 5 to 18% in females, but not in the males. This study demonstrates increase of tumours of semicarbazide hydrochloride in mice.

Reference 3

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

No GLP study.

Qualifier:

according to guideline

Guideline:

other: Guideline for carcinogen bioassay in small rodents (Washington, D.C.:US Govt Print Off, 1976)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Carcinogenicity testing: A report of the panel of the Cancer Research Commission of UICC, Vol 2. Geneva: UICC, 1969

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 451 (Carcinogenicity Studies)

Deviations:

yes

Remarks:

1.In the study, 26 animals/each sex were used,but according the TG 451 there should be used 50 animals/each sex. 2.The length of test. In the present study,length of the test was 18 months, but according the TG 451 the length should be 24 months.

GLP compliance:

not specified

Species:

rat

Strain:

other: Charles River CD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:Breeding laboratories, Non Wilmington, Mass.
- Housing: 2 per large plastic cage (12x14x7 inches) on corncob bedding (San-i-cel; Paxton Processing Co.,Inc., Paxton, Ill.).
- Diet (e.g. ad libitum):Wayne Lab Blox meal. Mixtures prepared as for the animal diets were stored for 10 days at room temperature to determine the possible degradation of the compound added.
- Water (e.g. ad libitum): ad libitum.
- Acclimation period:7-10 days

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
For diet mixing, a small portion of meal was mixed thoroughly in a mortar with the proper amount of the compound; the resultant concentrate was added to more meal and blended for 15-20 minutes in a twin-shell blender.

DIET PREPARATION
- Rate of preparation of diet (frequency):Diet was prepared in 6-kg lots twice weekly
- Storage temperature of food:in refrigerator at 4ºC

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

Required level (ppm): 500-1000
Recovery (%) : 83.6+-3.1
Stability in days: 9
Loss % : none

Duration of treatment / exposure:

Total weeks on drug: 78 weeks for animals tested at 500 ppm
Total weeks on drug: 32 weeks for animal tested at the highest dose of 1000 ppm

Frequency of treatment:

Daily

Post exposure period:

6 months

Dose / conc.:

500 ppm

Dose / conc.:

1 000 ppm

No. of animals per sex per dose:

26 animals per dose/sex (total 104)

Control animals:

yes

Details on study design:

- Dose selection rationale: The doses were selected according the previous study on Acute toxicity. Five distinct levels of each compund were mixed in diet, or given twice weekly in stomach tube to groups of 3 animals each over 30 days, followed by 30 days fo observation for detection of delayed toxicity.

Positive control:

2 groups with N-2-fluorenylacetamide in the diet at 80 ppm (32 rats) or 250 ppm (20 rats).

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes (mortality)

DETAILED CLINICAL OBSERVATIONS: Yes (The external observation - coat, legs,joints, behaviour.. )
- Time schedule: Twice daily, 7 days a week for toxicologic effects and death

BODY WEIGHT: Yes
- Time schedule for examinations: weekly during the initial month of the chronic study and beewekly thereafter.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined: Yes - during the initial week and the fourth week of each subsequent 4-week period.

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

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: No data

CLINICAL CHEMISTRY: No data

URINALYSIS: No data

NEUROBEHAVIOURAL EXAMINATION: No data

Sacrifice and pathology:

GROSS PATHOLOGY: No

HISTOPATHOLOGY: Yes, The tissues were fixed in 10% neutral buffered Formalin, sectioned, and stained with hematoxylin and eosin.Examintaion:cerebrum, cerebellum,pituitary gland, spinal cord plus vertebrae, lung, heart,mediastinum, thymus, thyroid gland, parathyroid gland,liver, spleen, pancreas, adrenal gland, kidney, urinary bladder, ovary, uterus or testis, accessory sex organ, esophagus, stomach, intestinal tract, and any abnormal tissue or mass.Animals were necropsied, and stained sections of the tissues were examined microscopically to detect any changes.

Statistics:

Probabilities of survival were estimated by the product-limit procedure of Kaplan and Meier (10), which is commonly called the "life table method." Animals were statistically censored as of the time they died of other than natural causes or were found to be missing; animals dying from natural causes were not statistically censored. For statistical analyses of a possible dose-related effect on survival, the method : extensions of Cox's methoas for testing for a dose-related trend were used.
One-tailed Fisher's exact probability test was used to compare the tumor incidence of a matched negative or vehicle control group with that of a group of dosed animals at each dose level. Inasmuch as the results for 2 dosed groups were compared simultaneously with those for a control group, a correction to ensure an overall significance level of 0.05 could be made.

The Bonferroni inequality requires that the P-value for any comparison be less than or equal to 0.0512 = 0.025.

The Cochran-Armitage test for linear trend in proportions, with continuity correction was also used, if the slope of the dose-response curve is different from zero at the one-tailed 0.05 level of significance.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Rough coat, protrusion of the sternum and bowing of the legs, and stiffness of the joints with bony growths (revealed by cleaning the bones) - osteolathyrism.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

The number of early death in each of the high dose was so large, that the treatment was dicontinued at week 32.A trend test for mortality yielded a significant association
for males but not for females.Survival was adequate in all the groups (at least 20 animals) at 78 weeks except for the high-dose males; of these only 13 survived to 52
weeks.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

For each sex the mean weights of the treated animals were less than those of the matched controls.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Osteoporosis was noted in the long bones.

Histopathological findings: neoplastic:

not specified

Other effects:

not examined

Relevance of carcinogenic effects / potential:

The author of this study confirmed that these results are negative.

Key result

Dose descriptor:

conc. level:

Effect level:

ca. 1 000 ppm

Based on:

test mat.

Sex:

male

Remarks on result:

other: Negative results

Body weight of control groups: MALES: 51 wk 709 g (range of mean body wt 644-760 g); at 77 wk - 766 g (718-854 g); and at 104 wk - 737 g (635-812 g).

FEMALES, corresponding: 402 g (357-447), 486 g (441-549), and 541 g (487-629)

Conclusions:

Under the test conditions, Semicarbazide hydrochloride gave negative results, though administered at sufficiently high dose levels to cause toxic effects in both sexes.

Executive summary:

According the publication from the Journal of the National Cancer Institute,the test item was tested for the carcinogenicity in the Charles River rats. In this chronic study chemicals was given to groups of 26 male and 26 female in the maximum tolerated doses and its half amount (1000 ppm and 500 ppm) in a diet form during 32 and 78 weeks, respectively. After the treatment, they were observed during 6 months.Control groups animal (matched and pooled) were used in the study.Two positive control groups with the N-2 -fluorenylacetamide were used to check the response to a known carcinogen at different dose level (80 ppm and 250 ppm). Ten negative male and 10 negative female control groups consisted of 184 animals. Rats were examinated twice daily, 7 days a week for toxicologic effects, weighted weekly during first month and then biweekly. Food consumption was determinated also. At the end of the study, the number of deaths in each of high-dose was so large, that the treatment was stopped at week 32. Survival was adequate in all the groups (at least 20 animals) at 78 weeks except for the high-dose males; of these only 13 survived to 52 weeks. Test substance caused osteolathyrism in all treated groups. Osteoporosis was noted in the long bones.Semicarbazide hydrochloride was tested in sufficiently high dose, which cause the toxic effects in both sexes, but there was no indication of tumor during the treatment.

Reference 4

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 451 (Carcinogenicity Studies)

Deviations:

yes

Remarks:

Duration of the sutdy should be 24 months according the TG 451. In the present study, duration of test was 7 months.

GLP compliance:

no

Species:

mouse

Strain:

other: dd mice

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 6-8week old
- Diet (e.g. ad libitum): basal diet, ad libitum

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:The amount of semicarbazide hydrochloride added to the diet was 0.1 %.

- Mixing appropriate amounts with (Type of food): Test substance was mixed with basal diet.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

7 months

Frequency of treatment:

Daily

Control animals:

not specified

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes, mortality

BODY WEIGHT: Yes

Sacrifice and pathology:

GROSS PATHOLOGY: Lungs

HISTOPATHOLOGY: Yes, pulmonary tumors

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The 75 % of incidence of pulmonary tumors were observed with average of 1.0 nodules per mouse.

Other effects:

not examined

Key result

Dose descriptor:

other: Incidence

Effect level:

ca. 75 other: %

Based on:

test mat.

Sex:

not specified

Basis for effect level:

histopathology: neoplastic

Incidence of pulmonary tumors in mice

Group	Treatment	N. of animals surviving 7 months	No. Of mice showing number of tumors per individual					Incidence %	Mean no of nodules per mouse	Carci. Index
			0	1	2	3	4
13	0.1% of SEM-HCl in diet	8	2	4	2			75	1.0	75

Conclusions:

Test substance induced pulmonary tumors. Incidence of tumors was 75% with average of 1.0 nodules per mouse.

Executive summary:

Test substance was tested for the carcinogenicity in the mouse. Test substance was administrated in amount of 0.1 % in the basal diet.Test duration was seven months and after that, the animals were killed for gross and histopathology examination. Animals fed with 0.1 % of semicarabide hydrochloride in diet had 75% incidence of pulmonary tumors with average of 1.0 nodules per mouse.As the results of this study is the fact, that test substance induce pulmonary tumors.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on available data from the various key and supporting studies, where the results were negative for carcinogenicity, Semicarbazide Hydrochloride is not classified as carcinogenic according to CLP Regulation no. 1272/2008.

Additional information

Key study:

According the present study, carcinogenicity effects of Semicarbazide hydrochloride were examinated in the male/females rats Wistar Hannover GALAS. Chronic toxicity study combined with carcinogenic study was performed. In the carcinogenicity study 50 males and 50 females rats per group (total 4 groups) during 104 weeks were used. The rats were fed a powdered diet containing SEMI HCl in 0 (control), 10,50 and 250 ppm. Animals were checked daily for clinical signs of toxicity and mortality, for body weights and food consumption,hematology analysis and gross examination. The toxicological targets were bones, cartilage and aorta. Based on histopathological findings, the NOAEL estimated from present study were 10 ppm (0.6 mg/kg/bw) in males and 50 ppm (3.9 mg/kg/bw) in females from the carcinogenicity study.SEM-HCl had no carcinogenic potential in male or female rats.

Key study:

In the present study obtained from the European Journal of Cancer, the administration of 0.0625% carbamylhydrazine hydrochloride in the drinking water was tested in 6-week-old Swiss albino mice during their lifes. Test substance in that doses enhanced the development of tumours of the lungs and blood vessels. As compared with the untreated controls, the incidence of lung tumors rose from 21 to 50% in the females and from 23 to 30% in the males, while the incidence of blood vessel tumours increased from 5 to 18% in females, but not in the males. This study demonstrates the increase of tumours of semicarbazide hydrochloride in mice.

Supporting study:

According the publication from the Journal of the National Cancer Institute,the test item was tested for the carcinogenicity in the Charles River rats. In this chronic study chemicals was given to groups of 26 male and 26 female in the maximum tolerated doses and its half amount (1000 ppm and 500 ppm) in a diet form during 32 and 78 weeks, respectively. After the treatment, they were observed during 6 months.Control groups animal (matched and pooled) were used in the study.Two positive control groups with the N-2 -fluorenylacetamide were used to check the response to a known carcinogen at different dose level (80 ppm and 250 ppm). Ten negative male and 10 negative female control groups consisted of 184 animals. At the end of the study, the number of deaths in each of high-dose was so large, that the treatment was stopped at week 32.Survival was adequate in all the groups (at least 20 animals) at 78 weeks except for the high-dose males; of these only 13 survived to 52 weeks. Test substance caused osteolathyrism in all treated groups. Osteoporosis was noted in the long bones.Semicarbazide hydrochloride was tested in sufficiently high dose, which cause the toxic effects in both sexes, but there was no indication of tumor during the treatment.

Supporting study:

Test substance was tested for the carcinogenicity in the mouse. Test substance was administrated in amount of 0.1 % in the basal diet.Test duration was seven months and after that, the animals were killed for gross and histopathology examination. Animals fed with 0.1 % of semicarabide hydrochloride in diet had 75% incidence of pulmonary tumors with average of 1.0 nodules per mouse. As the results of this study is the fact, that test substance induce pulmonary tumors.