polymeric zinc propylenebis(dithiocarbamate);propineb (ISO)

Carcinogenicity

Description of key information

No carcinogenic potential was observed in a reliable carcinogenicity study in mice. In addition, the results of a 2-year rat study were considered (study M-050009-01-1, summarized in Section 7.5.1). However, based on limitations in the study design (limited number of animals/group, limited histopathology), this data was not considered relevant for this endpoint. 

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records

Reference

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

August-1976 to September-1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 451 (Carcinogenicity Studies)

Version / remarks:

2018

Deviations:

no

GLP compliance:

no

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: WIGA Yersuchstierzucht, 8741 Sulzfeld
- Age at study initiation: Approx. seven weeks
- Weight at study initiation: Male mean weight: 36 g, Female mean weight: 28 g
- Housing: The animals were kept in pairs in Makrolon cages type I.
- Diet: Food was available ad libitum.
- Water: Water was available ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22° C ± 1° C
- Humidity (%): 56 ± 6 %

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Remarks:

The test item was incorporated into the diet.

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): 14 day intervals
- Mixing appropriate amounts with (Type of food): pulverised standard feed no. 1320 from Altromin Co.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

104 weeks

Frequency of treatment:

daily

Post exposure period:

none

Dose / conc.:

800 ppm

Remarks:

High dose group, equivalent to a mean daily intake of 106.3 mg/kg bw/d for males and 139.8 mg/kg bw/d for females.

Dose / conc.:

200 ppm

Remarks:

Mid dose group, equivalent to a mean daily intake of 26.2 mg/kg bw/d for males and 36.3 mg/kg bw/d for females.

Dose / conc.:

50 ppm

Remarks:

Low dose group, equivalent to a mean daily intake of 6.8 mg/kg bw/d for males and 8.9 mg/kg bw/d for females.

No. of animals per sex per dose:

The control group and the three dose groups each consisted of 50 animals/sex/dose.
For the haematological and clinical-chemical examinations and for urinalyses sub-groups were formed in addition to each group, and the sub-groups each consisted of 10 animals/sex/dose.

Control animals:

yes, concurrent no treatment

Observations and examinations performed and frequency:

Appearance and behaviour:
The animals were inspected daily for appearance and behaviour and pathological symptoms.

Body weights and feed consumption:
Up to the 6th study week the animals' weights were recorded weekly, and after this two-weekly. Feed consumption was determined weekly by weighing uneaten food.

Clinical laboratory examinations:
Examinations for haematology and clinical chemistry and urinalyses took place in the case of the sub-group animals before the start of the study and then every six months. The blood required
was taken from the retro-orbital venus plexus.

Haematology:
A CC-117 microcellcounter made by Toa Co., Japan, was used to establish the erythrocyte count/mm^3 and leucocyte count/mm^3. The haemoglobin content (g %) was determined by photometry using a method developed by Merck Co., Darmstadt. The differential blood count was made using smears (Giemsa stain), up to 100 cells per field of vision being counted at 1000
magnification.

Clinical chemistry:
The enzyme activities of alkaline phosphatase (AP in mU/mL) and glutamate pyruvate transaminase (GPT in mU/mL) in the blood serum to test liver function were determined by photometry using Merck Co.'s (Darmstadt) microlitre method.

Urinalyses:
Determination of protein, glucose, haemoglobin, bilirubin, urobilinogen and pH using Ames Co.'s Multistix, after collecting the urine from the mice in metabolism cages, was semiquantitative.
.

Sacrifice and pathology:

Gross pathology:
Autopsies of animals dying during the study:
The animals which died during the study were dissected, and all the organs grossly appraised and fixed in 10 % formalin solution.

Autopsies of the animals sacrificed at the end of the study:
At the end of the study the surviving mice were sacrificed with CO2, weighed, dissected and all their organs were grossly appraised. After weighing the brain, heart, lung, liver, spleen, kidneys (right and left), adrenals (right and left), thyroids (right and left) and gonads (testicles or ovaries,
right and left), these organs were fixed in 10 % formalin solution.

Statistics:

Using the single figures for body weights, feed consumption, organ weights, haematological and clinical-chemical data, means (m) and standard deviations (s.d.) were calculated for each group. The data was evaluated split for sex and dose group. To compare the treated animals with the controls Mann and Whitney's U Test (E. Weber, the F Test and T Test according to Student, Cavalli-Sforza) was used.

Clinical signs:

no effects observed

Description (incidence and severity):

During the entire study period the mice receiving 50 ppm, 200 ppm and 800 ppm Probineb in their feed did not differ in appearance and behaviour, either within the dose groups or compared with the controls. Their eating and drinking requirements and liveliness and condition of coat were similar in all groups.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

No dose related effect is apparent in any of the groups.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

During the study no differences were detected which could be attributed to dosage with the active ingredient.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

There were no indications of dose related differences in the quantities of feed consumed.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Haemoglobin:
Compared with the control, significant differences in haemoglobin level were noted in the male 50 ppm dose group before the start of the study and after 6 and 24 months, and in the 200 ppm
and 800 ppm dose groups after 6 months. In the case of the females significant deviations occurred in the 50 ppm treatment group before start of study and after 6 months, and in the
200 ppm and 800 ppm treatment groups after 6 months. The deviations are however without biological relevance, as they are neither in dose correlation nor outside the physiologically normal range.

Erythrocytes:
In the calculation of erythrocytes, significantly varying figures were found in both sexes, in the
males in the 50 ppm and 200 ppm groups before the start of the study and after 24 months, in the females in the 50 ppm group after 18 months, in the 200 ppm group after 12 months, and in the
800 ppm group before start of study and after 6 and 18 months. The deviations are however not attributable to dose-related effects. The values obtained were within the physiological range of variation.

Leucocytes:
The leucocyte counts showed significant differences before the start of the study, in the 50 ppm dose group, and in the 800 ppm dose group before the start of the study and after 12 and 18 months, only for the male animals. The means calculated after 12 and 18 months show, however, considerable standard deviations, as a result of which it does not seem justifiable to conclude that the effect is dose-related.

Differential blood count:
On evaluation of the lymphocytes the figures for the males treated with 50 ppm and 200 ppm, and
those treated with 800 ppm after 6, 12, 18 and 24 months, proved to deviate significantly from the control group figures. In the case of the female mice significant differences occurred in the 50 ppm and 200 ppm dose groups after 6 months and in the 800 ppm dose group after 18 months. Here however the alterations also are within the physiological range of variation.
The means of the segmented leucocytes differed significantly for the male animals in the 50 ppm
and 200 ppm feed groups after 6 months, and in the 800 ppm group after 6, 12 and 18 months. In the case of the females there were deviations in the 50 ppm and 200 ppm groups after 6 months. The differing figures were however in the range calculated for the control group, and in the normal range for mice, and were not in strict dose correlation. They are therefore not associated with a treatment-induced effect.
On evaluation of the monocytes there was a significant difference, which must be classed as random, only in the case of the male mice fed 50 ppm after 6 months.
The calculation of the eosinophile leucocytes produced significant differences in the 200 ppm dose group, males after 18, and females after 12 and 18 months. The alterations are however not biologically relevant.
In the case of the stab leucocytes and the basophile leucocytes no deviations were noted in either sex.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

Glutamate pyruvate transaminase:
The mean GPT values revealed significant deviations for the male mice in the 800 ppm dose group after 6 months, and in the 50 ppm, 200 ppm and 800 ppm group after 12 months. In the case of the females significantly deviating values were apparent on feeding with 200 ppm after 6 months, and with 50 ppm, 200 ppm and 800 ppm after 12 months. The values deviating from the control group were however in the normal range.

Alkaline phosphatase:
The AP values for the males deviated significantly after treatment with 200 ppm after 18 months, and those of the females after treatment with 50 ppm after 12 months, but within the physiological range.

Endocrine findings:

not examined

Urinalysis findings:

no effects observed

Description (incidence and severity):

The urine findings of 10 male and 10 female mice per sub-group over the entire study period do not reveal any differences between treated and untreated animals

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

The liver weights did not show any deviations in any group. On evaluation of the relative organ weights, for the male mice in the 50 ppm study group significant variations were revealed for brain, heart, lung, spleen, adrenal (right) and thyroid (right). In the 200 ppm treatment group there were significant deviations in organ weights for spleen, kidney (right) and testicles. The highest dose group (800 ppm) did not show any significant differences in organ weights. The fluctuations
are therefore to be considered random.
In the case of the females the relative organ weights for thyroid (left) in the 50 ppm and 800 ppm group were high. Due to the low number of animals at the end of the study, however, no conclusion may be drawn in regard to substance-related effect.

Gross pathological findings:

no effects observed

Description (incidence and severity):

On autopsy of the mice dying during the study there were no gross findings pointing to pathological alterations induced by the treatment with propineb.
The findings for the mice sacrificed at the end of the study do not produce on gross examination any effects attributable to feeding with propineb.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

In the case of the males in the highest dose group, histological examination detected nine hepatocellular adenomas compared with three hepatocellular adenomas and one hepatocellular
carcinoma in the male control group. As no dose-related effect specific to the liver could be attributed to propineb for NMRI mice, and four hepatocellular tumors also were found in the control, no special importance is attached to the slightly higher rate at 800 ppm.

Other effects:

not examined

Relevance of carcinogenic effects / potential:

In the case of the males in the highest dose group, histological examination detected nine hepatocellular adenomas compared with three hepatocellular adenomas and one hepatocellular
carcinoma in the male control group.
All mouse strains are subject to a certain spontaneous rate of hepatocellular neoplasms, and this rate also fluctuates. In the case of NMRI mice the laboratories experience had shown that spontaneous liver adenomas are found in 4-12 % of the animals. In certain mice strains this rate can rise up to 90 %. As no dose-related effect specific to the liver could be attributed to the test substance for NMRI mice, and four hepatocellular tumours also were found in the control, no special importance is attached to the slightly higher rate at 800 ppm. In addition the detailed investigation carried out by Loser in 1974 under the same conditions also produced the same negative results for
rats.

Key result

Dose descriptor:

NOAEL

Effect level:

800 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other:

Key result

Critical effects observed:

no

Conclusions:

This mouse carcinogenicity study was performed with propineb at dietary concentrations of 0, 50, 200 and 800 ppm. There was no evidence of carcinogenicity in this study; a slightly higher incidence of hepatocellular adenoma in 800 ppm males was not considered to be related to treatment.

Executive summary:

In a feeding study lasting 104 weeks groups of 50 male and 50 female NMRI mice per main group received propineb in concentrations of 50, 200 and 800 ppm added to their feed. 50 males and 50 females served as untreated controls. Haematology, clinical chemistry and urinalyses were conducted on groups of 10 male and 10 female animals per sub-group.
In regard to appearance, behaviour and mortality no effect attributable to the test substance was apparent in any of the dose groups. The treated animals' feed intake and body weight development did not differ from that of the controls.
The haematological values and urine findings for test groups and controls were within the physiological range.
The enzyme activities of glutamate pyruvate transaminase (GPT) and alkaline phosphatase (AP) in all the groups were within the physiologically normal range.
The increased weights of the left thyroids in the female mice in the 800 ppm dose group cannot be interpreted as associated with the substance due to the small number of animals at the end of the study. The remaining fluctuations in organ weights were not correlated to dose and were spontaneous.
The type and incidence of tumors in the organs examined did not point to propineb having a tumour-inducing effect. The slightly higher proportion of hepatocellular adenomas compared with the control in the case of the males in the 800 ppm group cannot be assigned any special significance in this respect, due to the relatively high spontaneous rate and fluctuation of these findings.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

106 mg/kg bw/day

Study duration:

chronic

Species:

mouse

Quality of whole database:

The available information comprises an adequate and reliable study.

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

The available data on carcinogenicity does not meet the criteria for classification according to Regulation (EC) 1272/2008, and is therefore conclusive but not sufficient for classification.