Ferbam

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline available

Principles of method if other than guideline:

Groups of 10-20 dams were treated from gestational Day 16 through postpartum Day 21. The animals were allowed to deliver normally and the pups were examined at birth and on lactational Days 4 and 21.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

other: Charles River CD rats

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, North Wilmington, Massachusetts.
- Fasting period before study:
- Housing: Animals were housed in stainless steel cages with wire screen bottoms or plastic cages with hardwood chip bedding. Six rats were housed per cage during acclimation, two rats per cage before mating and during gestation, and one per cage prior to delivery and thereafter.
- Diet (e.g. ad libitum): free access
- Water (e.g. ad libitum): free access
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 + 2°C
- Humidity (%): 50 + 10% relative humidity
- Photoperiod (hrs dark / hrs light): 7 AM-7 PM photoperiod

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

The experimental diets were prepared in a tumbling feed mixer every 1-2 weeks from a stock concentration of the fungicides and stored in sealed containers. The diets were stable under these conditions, and the ferbam diet showed no increase in thiram content during this time.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

The daily doses of fungicide (milligrams per kilogram) consumed were calculated from the average daily food consumptions. The ferbam doses were corrected for the inactive ingredients present in the formulation

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: one or two female rats with a proven male breeder
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

Groups of 10-20 dams were treated from gestational Day 16 through postpartum Day 21.

Frequency of treatment:

Groups of 10-20 dams were treated from gestational Day 16 through postpartum Day 21.

Duration of test:

Groups of 10-20 dams were treated from gestational Day 16 through postpartum Day 21. The animals were allowed to deliver normally and the pups were examined at birth and on lactational Days 4 and 21.

Dose / conc.:

0.015 other: %

Remarks:

0.015% ferbam in diet corresponds to daily doses of approximately 7.6 mg/kg before birth and 23 mg/kg after birth

Dose / conc.:

0.15 other: %

Remarks:

The diet that contained 0.15 % ferbam provided a daily dose of approximately 41 mg/kg of ferbam before birth and 152 mg/kg after birth.

No. of animals per sex per dose:

Groups of 10-20 dams per dose

Control animals:

yes, concurrent vehicle

Details on study design:

A group whose food intake was restricted to the least amount consumed by a fungicide-treated group during treatment was included to evaluate the effects of malnutrition on the growth and viability of pups.

Maternal examinations:

Feed intake, dam body weight on lactation days 0, 4 and 21

Fetal examinations:

Viability index, lactation index, pup body weight on lactation days 0, 4 and 21.
Pups were exchanged immediately after birth between control and four ferbam-treated dams in cross-fostering experiments.

Statistics:

The Fisher exact probability test (Siegel, 1956) and a two-sample rank test (Mann and Whitney, 1947) were used to evaluate the data. Values were reported as the means ± SE or the means. The level of significance was chosen as p < 0.05.

Indices:

Viability (pups alive at Day 4/pups alive at birth x 100), and lactation (pups alive at Day 21/pups alive at Day 4 x 100) indices were used to summarize the observations on reproduction.

Historical control data:

not specified

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Dams given the high dose of ferbam consumed less feed and gained less weight than control dams (Table 1).

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Dams given the high dose of ferbam consumed less feed and gained less weight than control dams (Table 1).

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Dams given the high dose of ferbam consumed less feed than control dams (Table 1).

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 examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Number of abortions:

not specified

Pre- and post-implantation loss:

not specified

Total litter losses by resorption:

not examined

Early or late resorptions:

not examined

Dead fetuses:

no effects observed

Description (incidence and severity):

The report states that the parturition was normal.

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

The average length of gestation was between 21 and 22 days, and parturition was normal.

Changes in number of pregnant:

not examined

Dose descriptor:

dose level:

Effect level:

0.15 other: %

Based on:

test mat.

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

Pups from dams given the high dose of ferbam (0.15 %) weighed less than control pups (see below, Table 2).

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

effects observed, treatment-related

Description (incidence and severity):

Pups from dams given the high dose of ferbam (0.15%) weighed less than control pups (see below, Table 2).

Changes in postnatal survival:

effects observed, treatment-related

Description (incidence and severity):

Pups from dams given the high dose of ferbam (0.15%) had reduced viability (see below, Table 2).

External malformations:

not examined

Skeletal malformations:

not examined

Visceral malformations:

not examined

Dose descriptor:

dose level:

Effect level:

0.15 other: % in diet

Based on:

test mat.

Sex:

not specified

Basis for effect level:

fetal/pup body weight changes

changes in postnatal survival

Developmental effects observed:

yes

Lowest effective dose / conc.:

0.15 other: % in diet

Treatment related:

yes

Relation to maternal toxicity:

developmental effects as a secondary non-specific consequence of maternal toxicity effects

Dose response relationship:

yes

Relevant for humans:

not specified

Table 1. Effect of ferbam administered to adult rats during perinatal and postnatal periods (administered from gestation day 16 to lactation day 21).

Ferbam in diet (%)	Feed intake^b before birth	Feed intake^b after birth	Dam body weight (g) Lactation day 0	Dam body weight (g) Lactation day 4	Dam body weight (g) Lactation day 21
0	32	68	362	354	363
0.015	30	65	354	362	360
0.15	14*	36*	281*	270*	339*
0^a	12	35	336*	291*	312

^a Food restricted to the amount indicated.

^b During the treatment period (g/rat/day)

* Significantly different from control (two-sample rank test).

Table 2. Effect of ferbam on offspring of rats treated during perinatal and postnatal periods ().

Diet (%)^a	Viability index	Lactation index	Pup body weight (g) on lactation day 0	Pup body weight (g) on lactation day 4	Pup body weight (g) on lactation day 21
0	97	94	6.6	10.5	48.5
0.015	89	96	6.2	9.3 b	41.4
0.15	33^b,c	51^b,c	4.9^b,c	4.9^b,c	20.5^b
0^d	88	90	5.6^b	8.1 b	26.9^b
0/0.15^e	43	88	6.3	5.7^b	19.5^b
0.15/0	94	87	4.9^b	7.3 ^b	45.1

^a administration from gestation day 16 to lactation day 21

^b Significantly different from normal control (two-sample rank test).

^c Signifcantly different from food-restricted group (two-sample rank test).

^d Food restricted to the amount indicated in Table 1).

^e Pups from dams fed control diet nursed by high-dose dams.

^f Pups from high-dose dams nursed by control dams.

Conclusions:

The peri- and postnatal administration of ferbam reduced food consumption and decreased body weight of dams. Pup survival and growth were also reduced by ferbam. The impaired survival associated with treatment was not due entirely to poor nutrition, since food restriction of controls did not affect viability of pups in the ferbam study. Cross-fostering experiments indicated that ferbam was most toxic to pups during the nursing period.

Executive summary:

The peri- and postnatal toxicity of ferbam was studied in rats. Groups of 10-20 dams were treated from gestational Day 16 through postpartum Day 21. The animals were allowed to deliver normally and the pups were examined at birth and on lactational Days 4 and 21. A group whose food intake was restricted to the least amount consumed by a ferbam-treated group during treatment was included to evaluate the effects of malnutrition on the growth and viability of pups. Pups were exchanged immediately after birth between control and four ferbam-treated dams in cross-fostering experiments.

The peri- and postnatal administration of ferbam reduced food consumption and decreased body weight of dams. Pup survival and growth were also reduced by ferbam. The impaired survival associated with treatment was not due entirely to poor nutrition, since food restriction of controls did not affect viability of pups in the ferbam study.

Cross-fostering experiments were conducted to determine whether treatment effects were produced in the prenatal or postnatal period. The body weights of pups from dams fed diets with the high concentration of ferbam were reduced at birth. When these pups were nursed by control dams their survival and body weights approached normal. On the other hand, normal pups that were nursed by dams fed the largest amount of ferbam had reduced body weights. Effects related to treatment with ferbam, which were produced in the prenatal period, were reversible and did not interfere with the growth and survival of the pups. The cross-fostering experiments indicated that ferbam was most toxic to pups during the nursing period. Since ferbam was transmitted to pups through the milk (Hodgson et at., 1975), it is probable that ferbam produces its toxicity by a direct action on the pups rather than indirectly as a result of toxicity to the dam.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

reporting deficiences and shortcomings in selection of doses (only two doses, ten-fold dilution step)

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

1981, study conducted prior to adoption of the OECD TG

Deviations:

yes

Remarks:

only two dose groups

GLP compliance:

not specified

Limit test:

no

Species:

mouse

Strain:

Swiss Webster

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: National Laboratory Animal Company, O'Fallon, Missouri.
- Housing: Animals were housed in stainless steel cages with wire screen bottoms or plastic cages with hardwood chip bedding. Ten mice were housed per cage during acclimation, five mice per cage before mating and during gestation, and one per cage prior to delivery and thereafter.
- Diet (e.g. ad libitum): free access
- Water (e.g. ad libitum): free access
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 + 2°C
- Humidity (%): 50 + 10% relative humidity
- Photoperiod (hrs dark / hrs light): 7 AM-7 PM photoperiod

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on exposure:

VEHICLE
- Amount of vehicle (if gavage): 0.5 % carboxylmethyl cellulose

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: two to five female mice with a proven male breeder
- Length of cohabitation: overnight
- Proof of pregnancy: vaginal plugs referred to as day 0 of pregnancy

Duration of treatment / exposure:

Mice were treated on Days 6-14 of gestation.

Frequency of treatment:

Mice were treated on Days 6-14 of gestation.

Duration of test:

Pregnant mice treated during organogenesis were sacrificed by CO2 on gestational Day 18.

Dose / conc.:

22 mg/kg bw/day (actual dose received)

Dose / conc.:

228 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

27 mice per dose

Control animals:

yes, concurrent vehicle

Maternal examinations:

Gestation body weight change

Ovaries and uterine content:

The uterine content was examined after termination: Yes
Examinations included:
- Number of implantations: Yes
- Number of resorptions: Yes

Fetal examinations:

- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: No data

Statistics:

The Fisher exact probability test (Siegel, 1956) and a two-sample rank test (Mann and Whitney, 1947) were used to evaluate the data. Values were reported as the means ± SE or the means. The level of significance was chosen as p < 0.05.

Indices:

Gestation (confirmed pregnancies with viable fetuses/confirmed pregnancies x 100) indices were used to summarize the observations on reproduction.

Historical control data:

not specified

Clinical signs:

not specified

Mortality:

mortality observed, non-treatment-related

Description (incidence):

Ferbam did not affect the survival of dams during gestation at doses of 23 or 228 mg/kg (see table).

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Ferbam did not affect the body weight change of dams during gestation at doses of 23 or 228 mg/kg (see table).

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 examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

Ferbam did not alter the incidence of resorptions (see table).

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

Ferbam did not alter the litter size (see table).

Early or late resorptions:

no effects observed

Description (incidence and severity):

Ferbam did not alter the litter size (see table).

Dead fetuses:

no effects observed

Description (incidence and severity):

Ferbam did not alter the litter size (see table).

Changes in pregnancy duration:

not examined

Changes in number of pregnant:

not examined

Key result

Dose descriptor:

NOAEL

Effect level:

228 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

mortality

other: litter size

Remarks on result:

other: highest dose tested

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Ferbam did not alter the fetal body weight (see table).

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

Ferbam did not alter the litter size (see table).

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

Ferbam did not alter the litter size or fetal body weight (see table).

Changes in postnatal survival:

not examined

External malformations:

effects observed, treatment-related

Description (incidence and severity):

The incidences of anomalies (fetuses affected/ fetuses inspected) in fetuses from dams given 228 mg/kg ferbam and the corresponding control group were: slight (6/96 vs 0/107), or marked (1/96 vs 0/107) collapsed cranium, extraossification of supraoccipitals (37/96 vs 16/107), and malaligned sternabrae (13/96 vs 6/107).

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

The incidences of anomalies (fetuses affected/ fetuses inspected) in fetuses from dams given 228 mg/kg ferbam and the corresponding control group were: slight (6/96 vs 0/107), or marked (1/96 vs 0/107) collapsed cranium, extraossification of supraoccipitals (37/96 vs 16/107), and malaligned sternabrae (13/96 vs 6/107).

Visceral malformations:

effects observed, treatment-related

Description (incidence and severity):

The incidences of anomalies (fetuses affected/ fetuses inspected) in fetuses from dams given 228 mg/kg ferbam and the corresponding control group were: thick atrial wall (5/88 vs 0/100), thin ventricular wall (8/88 vs 0/100), hydroureter (13/88 vs 1/100), and hydronephrosis (26/88 vs 21/100).

Key result

Dose descriptor:

dose level:

Effect level:

228 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

skeletal malformations

visceral malformations

Dose descriptor:

NOAEL

Remarks on result:

not determinable because of methodological limitations

Remarks:

The design of this study does not allow the derivation of a NOAEL due to the dose selection. There was a ten-fold difference between the doses applied.

Abnormalities:

effects observed, treatment-related

Localisation:

external: cranium

skeletal: sternum

visceral/soft tissue: cardiovascular

Description (incidence and severity):

The incidences of anomalies (fetuses affected/ fetuses inspected) in fetuses from dams given 228 mg/kg ferbam and the corresponding control group were: thick atrial wall (5/88 vs 0/100), thin ventricular wall (8/88 vs 0/100), hydroureter (13/88 vs 1/100), and hydronephrosis (26/88 vs 21/100), collapsed cranium, extraossification of supraoccipitals (37/96 vs 16/107), and malaligned sternabrae (13/96 vs 6/107).

Developmental effects observed:

yes

Lowest effective dose / conc.:

228 mg/kg bw/day (actual dose received)

Treatment related:

yes

Relation to maternal toxicity:

developmental effects as a secondary non-specific consequence of maternal toxicity effects

Dose response relationship:

yes

Relevant for humans:

yes

Table. Effect of ferbam administered to mice during organogenesis.

Ferbam dose (mg/kg)	Total rats dosed	No. of dams dosed	No. of dams alive	Gestation body weight change (%)	Implants (No. per dam)	Fetuses (No. per dam)	Resorptions (%)	Fetal body weight (g)
0	27	24	22	71	11.1 +/- 0.4	9.3 +/- 0.6	16 +/- 3	1.09
23	27	22	20	74	10.9 +/- 0.4	10.1 +/- 0.4	6 +/- 2	1.07
228	27	20	18	71	10.1 +/- 0.5	10.1 +/- 0.5	10 +/- 2	1.10

Conclusions:

In mice, ferbam did not affect the survival or body weight change of dams during gestation at doses of 23 or 228 mg/kg. Ferbam also did not alter the litter size, incidence of resorptions, or fetal body weight. However, treatment of dams with ferbam was associated with cardiovascular defects in fetuses.The authors conclude that most anomalies produced by treatment with ferbam, however, were probably due to depression of growth, since there was no pattern of well-defined anomalies that would suggest a specific teratogenic effect. Therefore, no conclusion on the potential teratogenicity of the test substance ferbam can be drawn from this study.

Executive summary:

The teratogenicity of the test item ferbam was studied in mice in a study comparable to OECD TG 414 (1981). Ferbam was administered to pregnant mice via oral gavage on gestation days d6 - d14.

Ferbam did not affect the survival or body weight change of dams during gestation at doses of 23 or 228 mg/kg. Ferbam also did not alter the litter size, incidence of resorptions, or fetal body weight. The incidences of anomalies (fetuses affected/ fetuses inspected) in fetuses from dams given 228 mg/kg ferbam and the corresponding control group were: thick atrial wall (5/88 vsO/100), thin ventricular wall (8/88 vs 0/100), hydroureter (13/88 vs 1/100), hydronephrosis (26/88 vs 21/100), slight (6/96 vs 0/107), or marked (1/96 vs 0/107) collapsed cranium, extraossification of supraoccipitals (37/96 vs 16/107), and malaligned sternabrae (13/96 vs 6/107).

The authors conclude that most anomalies produced by treatment with ferbam, however, were probably due to depression of growth, since there was no pattern of well-defined anomalies that would suggest a specific teratogenic effect. Therefore, no conclusion on the potential teratogenicity of the test substance ferbam can be drawn from this study. Regulatory dose descripors such as NOAEL and LOAEL were not derived in this study.

Cross-reference 3

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

reporting deficiences and shortcomings in selection of doses (only two doses, ten-fold dilution step)

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

1981, conducted prior to adoption of the OECD TG

Deviations:

yes

Remarks:

only two dose groups

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

other: Charles River CD rats

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, North Wilmington, Massachusetts.
- Housing: Animals were housed in stainless steel cages with wire screen bottoms or plastic cages with hardwood chip bedding. Six rats were housed per cage during acclimation, two rats per cage before mating and during gestation, and one per cage prior to delivery and thereafter.
- Diet (e.g. ad libitum): free access
- Water (e.g. ad libitum): free access
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 + 2°C
- Humidity (%): 50 + 10% relative humidity
- Photoperiod (hrs dark / hrs light): 7 AM-7 PM photoperiod

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on exposure:

VEHICLE
- Amount of vehicle (if gavage): 0.5% carboxylmethyl cellulose

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: one or two female rats with a proven male breeder
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

Rats were treated on Days 6-15 of gestation.

Frequency of treatment:

Rats were treated on Days 6-15 of gestation.

Duration of test:

Pregnant rats treated during organogenesis were sacrificed by CO2 on gestational Day 20.

Dose / conc.:

11 mg/kg bw/day (actual dose received)

Dose / conc.:

114 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

control: 17 animals; 11 mg/kg*d: 18 animals; 114 mg/kg*d: 15 animals

Control animals:

yes, concurrent vehicle

Maternal examinations:

Gestation body weight change

Ovaries and uterine content:

The uterine content was examined after termination: Yes
Examinations included:
- Number of implantations: Yes
- Number of resorptions: Yes

Fetal examinations:

- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: No data

Statistics:

The Fisher exact probability test (Siegel, 1956) and a two-sample rank test (Mann and Whitney, 1947) were used to evaluate the data. Values were reported as the means ± SE or the means. The level of significance was chosen as p < 0.05.

Indices:

Gestation (confirmed pregnancies with viable fetuses/confirmed pregnancies x 100) indices were used to summarize the observations on reproduction.

Historical control data:

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

Rats died at the 114-mg/kg dose level but 75 % of the dams survived.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The total change in body weight during gestation was reduced by ferbam (control: 60 % body weight change; 11 mg ferbam/kg bw: 49% body weight change; 114 mg ferbam/kg bw: 20 % body weight change) and reached significance at 114 mg/kg.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

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 examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Number of abortions:

not specified

Total litter losses by resorption:

effects observed, treatment-related

Description (incidence and severity):

The incidence of resorptions (control: 3 +/- 1 %; 11 mg ferbam/kg bw: 7 +/- 4 %; 114 mg ferbam/kg bw: 21 +/- 11 %) was increased but did not reach significance (see table).

Early or late resorptions:

not specified

Dead fetuses:

not specified

Changes in pregnancy duration:

not specified

Changes in number of pregnant:

not specified

Dose descriptor:

NOAEL

Remarks on result:

not determinable because of methodological limitations

Remarks:

The design of this study does not allow the derivation of a NOAEL due to the dose selection. There was a ten-fold difference between the doses applied.

Key result

Dose descriptor:

conc. level: induction of significant effects

Effect level:

114 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

other: decrease in number of fetuses per dam

Abnormalities:

no effects observed

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

Fetal body weight was decreased by ferbam (see table).

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

effects observed, treatment-related

Description (incidence and severity):

The authors mention that some dams had small litters, and there was a significantly decreased number of fetuses per dam in the high dose group (see table).

Changes in postnatal survival:

not examined

External malformations:

effects observed, treatment-related

Description (incidence and severity):

The incidences of anomalies (fetuses affected/fetuses inspected) in fetuses from dams given 114 mg/kg ferbam and the corresponding control group were: slightly collapsed cranium (7/31 vs 0/76), malformed cranium (2/35 vs 0/90), hydrocephalus (2/35 vs 0/90), and cleft palate (1/35 vs 0/90).

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

The incidences of anomalies (fetuses affected/fetuses inspected) in fetuses from dams given 114 mg/kg ferbam and the corresponding control group were: unossified sternabrae (20/31 vs 9/76), slightly collapsed cranium (7/31 vs 0/76), malformed cranium (2/35 vs 0/90), hydrocephalus (2/35 vs 0/90), hematoma (2/73 vs 0/180), and cleft palate (1/35 vs 0/90).

Visceral malformations:

not specified

Other effects:

effects observed, treatment-related

Description (incidence and severity):

The incidences of anomalies (fetuses affected/fetuses inspected) in fetuses from dams given 114 mg/kg ferbam and the corresponding control group were: hematoma (2/73 vs 0/180).

Key result

Dose descriptor:

dose level: increased incidence of anomalies

Effect level:

114 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

external malformations

skeletal malformations

Dose descriptor:

NOAEL

Remarks on result:

not determinable because of methodological limitations

Remarks:

The design of this study does not allow the derivation of a NOAEL due to the dose selection. There was a ten-fold difference between the doses applied.

Abnormalities:

effects observed, treatment-related

Localisation:

external: cranium

skeletal: skull

skeletal: sternum

Description (incidence and severity):

The incidences of anomalies (fetuses affected/fetuses inspected) in fetuses from dams given 114 mg/kg ferbam and the corresponding control group were: unossified sternabrae (20/31 vs 9/76), slightly collapsed cranium (7/31 vs 0/76), malformed cranium (2/35 vs 0/90), hydrocephalus (2/35 vs 0/90), hematoma (2/73 vs 0/180), and cleft palate (1/35 vs 0/90).

Developmental effects observed:

yes

Lowest effective dose / conc.:

114 mg/kg bw/day (actual dose received)

Treatment related:

yes

Relation to maternal toxicity:

developmental effects as a secondary non-specific consequence of maternal toxicity effects

Dose response relationship:

yes

Relevant for humans:

yes

Table. Effect of ferbam administered to rats during organogenesis.

Ferbam dose (mg/kg)	Total rats dosed	No. of dams dosed	No. of dams alive	Gestation body weight change (%)	Implants (No. per dam)	Fetuses (No. per dam)	Resorptions (%)	Fetal body weight (g)
0	17	13	13	60	14.3 +/- 0.5	13.9 +/- 0.6	3 +/- 1	3.8 +/- 0.1
11	18	13	12	49	14.9 +/- 0.8	13.8 +/- 0.9	7 +/- 4	3.4 +/- 0.2
114	15	12	9	20*	10.0 +/- 1.9	9.1 +/- 2.0*	21 +/- 11	2.9 +/- 0.2*

*Significantly different from control value (two-sample rank test).

Conclusions:

Ferbam produced mortality and reduced weight gained during gestation in rats at doses of 114 mg/kg. There was also a reduction in litter size and fetal body weight at this dose. Treatment of dams with ferbam was associated with hydrocephalus in fetuses. The authors conclude that most anomalies produced by treatment with ferbam, however, were probably due to depression of growth, since there was no pattern of well-defined anomalies that would suggest a specific teratogenic effect. This interpretation is supported by the fact that the dose of ferbam that caused overt toxicity in the dams was required to produce anomalies in rat fetuses.

Executive summary:

The teratogenicity of the test item ferbam was studied in rats in a study comparable to OECD TG 414 (1981). Ferbam was administered to pregnant rats via oral gavage on gestation days d6 - d15.

Rats died at the 114-mg/kg dose level but 75 % of the dams survived. The total change in body weight during gestation was reduced by ferbam. There was a reduction in litter size and an increased incidence of resorptions. In addition, fetal body weight was decreased by ferbam

The incidences of anomalies (fetuses affected/fetuses inspected) in fetuses from dams given 114 mg/kg ferbam and the corresponding control group were: unossified sternabrae (20/31 vs 9/76), slightly collapsed cranium (7/31 vs 0/76), malformed cranium (2/35 vs 0/90), hydrocephalus (2/35 vs 0/90), hematoma (2/73 vs 0/180), and cleft palate (1/35 vs 0/90).

The authors conclude that most anomalies produced by treatment with ferbam, however, were probably due to depression of growth, since there was no pattern of well-defined anomalies that would suggest a specific teratogenic effect. This interpretation is supported by the fact that dose of ferbam that caused overt toxicity in the dams was required to produce anomalies in rat fetuses. Regulatory dose descripors such as NOAEL and LOAEL were not derived in this study.

Data source

Reference

Reference Type:

publication

Title:

Developmental toxicity of ferric dimethyldithiocarbamate and bis(dimethylthiocarbamoyl) disulfide in rats and mice.

Author:

Short RD Jr et al.

Year:

1976

Bibliographic source:

Toxicol Appl Pharmacol. 35(1):83-94.

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Contains elements of OECD Guideline 415, but either male or female rats were dosed prior to mating.

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Ferbam

EC Number:

238-484-2

EC Name:

Ferbam

Cas Number:

14484-64-1

Molecular formula:

C9H18FeN3S6

IUPAC Name:

iron(3+) tris(dimethyldithiocarbamate)

Details on test material:

Ferbam formulation: Stauffer Chemical Company, New York, New York. Lot No. M6O072ET.
The formulation of ferbam contained 76% active and 24% inactive ingredients. Chemical analysis indicated that this preparation contained approximately 13% iron, 1 % thiram, and 0.3 % lead.

Test animals

Species:

rat

Strain:

other: CD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, North Wilmington, Massachusetts.
- Fasting period before study:
- Housing: Animals were housed in stainless steel cages with wire screen bottoms or plastic cages with hardwood chip bedding. Six rats were housed per cage during acclimation, two rats per cage before mating and during gestation, and one per cage prior to delivery and thereafter.
- Diet (e.g. ad libitum): free access
- Water (e.g. ad libitum): free access
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 + 2°C
- Humidity (%): 50 + 10% relative humidity
- Photoperiod (hrs dark / hrs light): 7 AM-7 PM photoperiod

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

The experimental diets were prepared in a tumbling feed mixer every 1-2 weeks from a stock concentration of the fungicides and stored in sealed containers. The diets were stable under these conditions, and the ferbam diet showed no increase in thiram content during this time.

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: one or two female rats with a proven male breeder
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Male rats were treated for at least 13 weeks before mating with untreated females.
Virgin females were treated for at least 14 days, and then mated with untreated males.

Details on study schedule:

Male rats were treated for at least 13 weeks before mating with untreated females. Males were exposed to females until sperm were found in vaginal smears of two females or until five receptive females had been exposed. One-half of the females in each group was sacrificed by CO2 on gestational Day 13, and the uterus and its contents were examined. The remaining animals were allowed to deliver and the pups were examined at delivery, on Day 4, and on Day 21.
Virgin females were divided into groups of 20 animals each, treated for at least 14 days, and then mated with untreated males. After mating, all females were fed the control diet. One-half of the females in each group was sacrificed by CO2 on gestational Day 13 and the uterus and its contents were examined. Pups of the remaining animals were examined at birth and on postpartum Days 4 and 21.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

23 mg/kg bw/day (actual dose received)

Remarks:

male rats, average daily dose during the treatment period (0.05% ferbam in diet)

Doses / concentrations 2

Dose / conc.:

66 mg/kg bw/day (actual dose received)

Remarks:

male rats, average daily dose during the treatment period (0.12% ferbam in diet)

Doses / concentrations 3

Dose / conc.:

109 mg/kg bw/day (actual dose received)

Remarks:

male rats, average daily dose during the treatment period (0.25% ferbam in diet)

Doses / concentrations 4

Dose / conc.:

15 mg/kg bw/day (actual dose received)

Remarks:

female rats, average daily dose during the treatment period (0.04% ferbam in diet)

Doses / concentrations 5

Dose / conc.:

51 mg/kg bw/day (actual dose received)

Remarks:

female rats, average daily dose during the treatment period (0.2% ferbam in diet)

No. of animals per sex per dose:

20 animals per sex per dose

Control animals:

yes, plain diet

Positive control:

not specified

Examinations

Parental animals: Observations and examinations:

mortality, daily food consumption, body weights; indices of fertility, gestation, viability and lactation

Sperm parameters (parental animals):

not specified

Litter observations:

viability at birth, at day 4 and at day 21

Postmortem examinations (parental animals):

not examined

Postmortem examinations (offspring):

not examined

Statistics:

The Fisher exact probability test (Siegel, 1956) and a two-sample rank test (Mann and Whitney, 1947) were used to evaluate the data. Values were reported as the means ± SE or the means. The level of significance was chosen as p < 0.05.

Reproductive indices:

Fertility (confirmed pregnancies/sperm positive females x 100), gestation (confirmed pregnancies with viable fetuses/confirmed pregnancies x 100), viability (pups alive at Day 4/pups alive at birth x 100), and lactation (pups alive at Day 21/pups alive at Day 4 x 100) indices were used to summarize the observations on reproduction.

Offspring viability indices:

viability (pups alive at Day 4/pups alive at birth x 100), and lactation (pups alive at Day 21/pups alive at Day 4 x 100) indices

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Male rats: Six of 24 rats fed the 0.25 % ferbam diet died between the second and sixth week of treatment.

Female rats: no rat died during the treatment.

Mortality:

mortality observed, treatment-related

Description (incidence):

Male rats: six of 24 rats fed the 0.25 % ferbam diet died between the second and sixth week of treatment.

Female rats: no rat died during the treatment.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Male rats: the average body weights of the rats given 23, 66, and 109 mg/kg ferbam were 93, 85, and 70 % of the control value (488 g), respectively, at the end of 13 weeks.

Female rats: the average body weights of rats given an average daily dose of 15, or 51 mg/kg of ferbam were 93 and 85 % of the control value (289 g) at the end of 2 weeks.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Male rats: the average daily food consumption for rats given 23, 66, and 109 mg/kg ferbam was 91, 83, and 64 % of the control value (22 g/rat).

Female rats: the average daily food consumption during 14 days treatment was 85 and 51 % of control value (16 g/rat).

Food efficiency:

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

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Description (incidence and severity):

Male rats: the indices of fertility, gestation, viability, and lactation for untreated females mated with fnales receiving 0.05, 0.12, or 0.25 % ferbam diets were not significantly different from control values.

Female rats: the indices of fertility, gestation, viability, and lactation for rats given 0.04 or 0.2 % ferbam diets were not significantly different from control indices.

Effect levels (P0)

1

Dose descriptor:

dose level: no effects observed

Effect level:

66 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

mortality

2

Dose descriptor:

dose level: no effects observed

Effect level:

51 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Remarks on result:

other: highest tested dose, no adverse effects observed

Target system / organ toxicity (P0)

Critical effects observed:

not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Description (incidence and severity):

Treatment of male rats: the indices of fertility (confirmed pregnancies/sperm positive females x 100), gestation (confirmed pregnancies with viable fetuses/confirmed pregnancies x 100), viability (pups alive at Day 4/pups alive at birth x 100), and lactation (pups alive at Day 21/pups alive at Day 4 x 100) for untreated females mated with males receiving 0.05, 0.12, or 0.25 % ferbam diets were not significantly different from control values.
Treatment of female rats: the indices of fertility, gestation, viability, and lactation for rats given 0.04 or 0.2 % ferbam diets were not significantly different from control indices.

Mortality / viability:

no mortality observed

Description (incidence and severity):

The indices of fertility (confirmed pregnancies/sperm positive females x 100), gestation (confirmed pregnancies with viable fetuses/confirmed pregnancies x 100), viability (pups alive at Day 4/pups alive at birth x 100), and lactation (pups alive at Day 21/pups alive at Day 4 x 100) for untreated females mated with males receiving 0.05, 0.12, or 0.25 % ferbam diets were not significantly different from control values.
Treatment of female rats: the indices of fertility, gestation, viability, and lactation for rats given 0.04 or 0.2 % ferbam diets were not significantly different from control indices.

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not specified

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Effect levels (F1)

1

Dose descriptor:

dose level: no effects observed

Generation:

F1

Effect level:

109 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: highest dose tested in male rats, no adverse effects on reproduction reported

2

Dose descriptor:

dose level: no effects observed

Generation:

F1

Effect level:

51 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: highest dose tested in female rats, no adverse effects on reproduction reported

Target system / organ toxicity (F1)

Critical effects observed:

not specified

Overall reproductive toxicity

Reproductive effects observed:

no

Applicant's summary and conclusion

Conclusions:

In ferbam-treated parental male rats exposed to 109 mg/kg/d, observed signs of toxicity included mortality. Ferbam did not affect reproduction in males treated with doses of 109 mg/kg/d. Reproduction in females was not affected by treatment with ferbam at doses of 51 mg/kg/d, and no female rat died following treament with up to 51 mg/kg/d.

Executive summary:

The reproductive toxicity of the test item ferbam was investigated in a non-guideline study in rats. In this study, male rats were treated for at least 13 weeks before mating with untreated females, or virgin females were treated for at least 14 days and then mated with untreated males. One-half of the females in each group was sacrificed by CO2 on gestational Day 13, and the uterus and its contents were examined. The remaining animals were allowed to deliver and the pups were examined at delivery, on Day 4, and on Day 21.

In this study, signs of toxicity included mortality observed in male rats exposed to 109 mg/kg/d, and reduced feed consumption in both male and female rats which may be caused by decreased palatability.

No treatment-related effects on fertility (confirmed pregnancies/sperm positive females), gestation (confirmed pregnancies with viable fetuses/confirmed pregnancies), viability of pups (pups alive at day 21/pups alive at day 4) and lactation (pups alive at day 21/pups alive at day 4) were observed in male and female rats. Consequently, no adverse effect on reproduction was observed for the test item ferbam in male rats up to the highest examined dose of 109 mg/kg/d, and in female rats up to the highest examined dose of 51 mg/kg/d. Regulatory dose descripors such as NOAEL and LOAEL were not derived in this study.