Zinc EDDHA

Endpoint summary

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Effects on fertility

Description of key information

There is no data available for the registered substance on reproductive toxicity. However, there is data available for the source substances FeNaEDDHMA and zinc salts.

FeNaEDDHMA

OECD 415, GLP, oral, rat, NOAEL = 200 mg/kg bw/day based on a slight decrease in the conception indices and a minimal delay in precoital time noted at the high dose level of 750 mg/kg bw/day.

Zinc chloride

Two generation study, oral gavage, rat, NOAEL (general toxicity) = 7.5 mg/kg bw/day; NOAEL (reproductive toxicity) = 15 mg/kg bw/day was determined for ZnCl2. These NOAELs was converted to the target substance taking into account the Zn content of 7.5 % leading to NOAEL (general toxicity) = 49.8 mg/kg bw/day ; NOAEL (reproductive toxicity) = 99.6 mg/kg bw/day.

Further information can be found under 'Additional information'.

Link to relevant study records

Reference

Reference 1

Endpoint:

one-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

In the 750 mg/kg bw/day group hunched posture, piloerection and emaciated and/or pale appearance were noted. A few males of the 200 mg/kg bw/day group showed hunched posture.

Mortality:

mortality observed, treatment-related

Description (incidence):

In the 750 mg/kg bw/day group, 1/28 males and 4/28 females died during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weight gain was decreased in animals of both sexes at 750 mg/kg bw/day and in males at 200 mg/kg bw/day. This decrease was dose-related. During the lactation period, body weight gain of females at 750 mg/kg bw/day showed a marked increase. Body weight ratios were decreased during the first 5 weeks of treatment for males and during the first 3 weeks for females at 750 mg/kg bw/day.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption was decreased in animals of both sexes at 750 mg/kg bw/day and in males at 200 mg/kg bw/day. Food consumption of males receiving 50 mg/kg/day and of females receiving 50 or 200 mg/kg/day remained in the same range as controls, before and after correction for the body weight.
Food consumption was decreased with statistical significance compared to controls, in males receiving 200 mg/kg/day from day 57 of treatment until termination and in males receiving 750 mg/kg/day from the beginning until the end of treatment. Following correction for the body weight, relative food consumption of males receiving 750 mg/kg/day showed a statistically significant decrease in comparison with control males between days 1 to 36 of treatment.
The food consumption of females treated at 750 mg/kg/day was noted as decreased during the premating period and until the end of the gestation period. During the period of lactation the food consumtion of females treated at 750 mg/kg/day was similar as control females. Relative food consumption was decreased during the premating period and during the first week of the gestation period only. In all cases the difference with control females was statistically significant.

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

There was no histopathological evidence of toxicity or infertility.

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

effects observed, treatment-related

Description (incidence and severity):

A slight delay of the precoital time in the 750 and 200 mg/kg dose groups was observed.
For all males and females that were paired, mating could be confirmed, resulting in 100 percent mating for each dose group. The fertility and conception indices of the 200 and 50 mg/kg dose groups were comparable with the control group. In the 750 mg/kg dose group these indices were considered to be slightly low, although the difference with controls did not achieve a level of statistical significance.
The gestation index was 100% in all treatment groups and were not affected by treatment with FeEDDHMANa.
In the absence of concomitant histopathological findings, a slight decrease of the fertility and conception indices was noted at 750 mg/kg bw/day.

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: systemic toxicity: based on clinical signs, incidences of mortality, and changes in body weight and food consumption at higher dose levels

Dose descriptor:

NOAEL

Effect level:

200 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: reproductive toxicity, fertility: based on a slight decrease in the conception indices and a minimal delay in precoital time at 750 mg/kg bw/day.

Critical effects observed:

no

Clinical signs:

no effects observed

Description (incidence and severity):

There were no unexpected clinical signs seen among pups of any dose group. Signs that were more frequently observed among the pups of all treatment groups during the first litter check (FLC), post partum phase and last litter check (LLC), consisted of hypothermia, no milk in the stomach and small appearance. These signs normally precede the death of non-viable pups and were considered not to represent a distinct toxic effect caused by the test substance.

Mortality / viability:

mortality observed, treatment-related

Description (incidence and severity):

Adverse effects on the F1-offspring consisted of an increased mortality rate during postnatal days 0-4 seen across the treatment groups (please refer to the table 1 in the section "Any other information on results incl.tables". The majority of the post natal loss was attributable to a few litters of each group, including 1, 3 and 3 litters in the low, mid and high dose groups, respectively. For further details, please refer to the table 2 in the section "Any other information on results incl. tables".

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Reduced body weights were noted during days 4 to 21 of lactation in pups of the high dose group (750 mg/kg bw/day).

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no test item related macroscopic findings.

Histopathological findings:

not examined

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

50 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Critical effects observed:

no

Reproductive effects observed:

not specified

Comparison of the relative number of live and dead pups during the various phases of lactation (i.e. first litter check, post partum days 0-4 and post partum days 5-21) revealed a statistically significant increase in post natal loss during days 0-4 in all treatment groups. The Viability Indices of these groups were correspondingly low. However, it was noted that the number of pups found dead at the first litter check (FLC) of control dams, were relatively high in comparison with the treatment groups. In accordance with these findings a relatively low Live Birth Index was noted in control litters. The following number of decedents among the F1-offspring was noted when calculating the total number of deaths during days 0-4 Post partum including the FLC:

Table 1: TOTAL DEAD PUPS DURING FLC & DAYS 0-4 P.P.

	GROUP 1 0 MG/KG	GROUP 2 50 MG/KG	GROUP 3 200 MG/KG	GROUP 4 750 MG/KG
Litters affected	5	8	9	6
Total dead pups	21	24	44	42
Mean	0.9	0.9	1.7	2.2
N (litters)	24	27	26	19

When comparing the total number of dead pups over the first 4 days of lactation, including the FLC, the mean number of dead pups per litter in the 50 mg/kg dose group equals the number in the control group. At the 200 and 750 mg/kg dose level, the mean number of deaths per litter revealed a dose-related increase when compared to the control group. A similar pattern was seen in the Overall Surviving Indices of the treatment and control groups. However, it must be considered that 2 females of the 750 mg/kg dose group died on the first day of lactation and that therefore 26 of 29 of their pups were killed in extremis.

After culling of all litters to 4 male and 4 female pups (if practically possible), the low mortality rate seen among pups of the treatment groups was comparable to that of the control group. This was also reflected by the comparable Weaning indices in control and treated groups.

Table 2: POSTNATAL LOSS AND VIABILITY
Endpoint	Dose Group [mg/kg bw/day]
	0	50	200	750
Dams with total litter loss at FLC [n]	1	0	0	0
(Pups lost [n])	(13)
Dead pups at FLC [n]	19	3	5	3
(Litters [n])	(5)	(3)	(3)	(1)
Postnatal loss PND 0-4 [n]	2	21	39	39
(Litters [n])	(1)	(7)*	(7)	(6)
Viability index (%)	99.4	94.9	90.4	85.4
FLC: first litter check
*: including 1 female with total pup loss (15/15)

CHEMICAL ANALYSIS

For the nominal concentrations of 0, 10, 40 and 150 mg/g, the concentrations analysed were in agreement with the concentrations prepared in this study. The test item was found to be mixed homogeneously through the vehicle and to be stable for 4 hours at ambient temperature.

Conclusions:

Based on the mortality observed in animals of the high dose group, and the reduced body weight gain and food consumption seen in animals of the mid- and high-dose groups, a parental No Observed Adverse Effect Level (NOAEL) of 50 mg/kg was established. Due to the increased post natal loss and reduced viability index in the treatment groups observed on post natal Days 0-4, the developmental NOAEL could, in fact, not be established. However, based on the results of the 28-day and 90-day study with FeEDDHMANa, it cannot be excluded that anaemia and/or impaired renal function may have been present that finally caused the observed litter losses. On the other hand, the finding in the low dose group consisted of only one female with total litter loss (15 pups) and 6 other females with 1 dead pup/litter which was within normal limits and might have occurred by chance. Therefore, a developmental NOAEL of 50 mg/kg might be considered; effects at higher levels were considered to be closely related to (subclinical) maternal toxicity. The same result is expected for the target substance since the nature of the constituents of the source substance is the same and they act via the same mechanism. No differences in the magnitude of the effects are expected. Therefore the same NOAEL is also applicable for the target substance.

Executive summary:

In an one-generation reproduction toxicity study FeEDDHMANa in distilled water was administered to 28 Wistar rats/sex/dose level by single oral gavage (5 mL/kg bw) at dose levels of 50, 200 or 750 mg/kg bw/day. A concurrent control group was treated with the vehicle only. Treatment commenced 10 weeks prior to mating for males and 2 weeks prior to mating for females and continued for both sexes until at least the end of the lactation period. Pregnant females were allowed to litter normally. On day 4 of lactation, each litter was adjusted to 4 males and 4 females or as near as possible. The surviving offspring was euthanised as soon as possible after weaning.

The primary effect of treatment with the test item on parental animals was poor physical condition, resulting in premature mortality, growth reduction and reduced food consumption in male and female animals at 750 mg/kg bw/day. These signs of test item-related toxicity were seen with reduced severity at 200 mg/kg bw/day in males only. Thus, the NOAEL for systemic toxcity in parental animals was 50 mg/kg bw/day under the conditions of this study.

In the offspring, increased post natal loss and reduced viability were noted during PND 0 -4 at 200 and 750 mg/kg bw/day, and with lower incidence at 50 mg/kg bw/day. With special regard to the low incidence and unusual distribution pattern of findings noted at 50 mg/kg bw/day, the NOAEL for developmental toxicity was 50 mg/kg bw/day under the conditions of this study.

Based on a slight decrease in the conception indices and a minimal delay in precoital time at 750 mg/kg bw/day, the NOAEL for reproductive performance/fertility was 200 mg/kg bw/day.

This study is acceptable and satisfies the guideline requirement for a one-generation reproduction toxicity study (OECD 415).

Reference 2

Endpoint:

two-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Species:

rat

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Aggression/hyperactivity throughout the study in both males and females, hair loss behind the ears in males, vaginal discharges in low and high dose females; 0-20 and 12-24 % mortality in males and females respectively.

Mortality:

mortality observed, treatment-related

Description (incidence):

The males experienced 0, 8, 20, and 12% mortality in control, low-, mid- and high-dose groups, respectively. The mortality among the females was 12, 24, 28, and 24% for the control, low-, mid- and high-dose groups, respectively. All unscheduled deaths were confined to the ZnCl2-treated groups, the majority of them probably being related to toxicity, but histomorphologic confirmation of this was not noted.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

All ZnCl2-treated F0 males experienced significant reduction in body weight after the 1st week of dosing and this trend continued up to the end of the experiment. The total weight gain of males was significantly reduced (dose dependent) in the low-, mid- and high-dose groups. In the F0 females, total weight gain and percent reduction in the low- mid- and high-dose groups were not significantly different from the control.
Postpartum dam body weight: The F0 and F1 post-partum dam weights in all dose groups were significantly different from their control groups.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

no effects observed

Description (incidence and severity):

ZnCl2-treatment to F0 and F1 males and females caused no significant effects on their feed efficiencies when compared to their control groups

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Description (incidence and severity):

None of the hemogram or leukogram values of both Fo and F1 males and females among the ZnCl2-treated groups were different from those of the control groups. However, there was a trend toward decreased values of Packed Cell Volume (PCV). The clinical chemistry findings in males and females of both generations did not show any significant difference from those of their controls. However, in mid- and high-dose males of both generations, there seemed to a trend toward elevated values of Amyl, ALK, and GLu.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

The clinical chemistry findings in males and females of both generations did not show any significant difference from those of their controls

Endocrine findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

The most consistent finding was aggression/hyperactivity which was observed throughout the study in both Fo and F1 males and females of ZnCl2-treated groups.

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

In both Fo and F1 males, the most biologically meaningful lesions were found in the reproductive system (prostatic acinar atrophy and inflammation) and the hematopoieticlymphoreticular system (splenic lymphoid depletion and hemosiderosis and thymic atrophy) of ZnCl2-treated groups (data are not shown). No significant changes in clinical pathology values or organ weights correlated with these lesions. None of the microscopic changes in target organs were of great magnitude. All unscheduled deaths were confined to the ZnCl2-treated groups, the majority of them probably being related to toxicity, but histomorphologic confirmation of this was not noted. The histopathology observed among the ZnCl2-treated females of both Fo and F1 generations was similar to that seen in the males, except that no lesions were seen in the reproductive system. The correlations and biological interpretations were also very similar.

Histopathological findings: neoplastic:

no effects observed

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

effects observed, treatment-related

Description (incidence and severity):

In F0 rats, ZnCl2 treatment caused a significant reduction on the fertility, litter size, and the viability indices (Days 0 and 4) were significantly reduced at the high-dose group compared to control.

Dose descriptor:

NOAEL

Effect level:

49.8 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male/female

Basis for effect level:

other: general toxicity

Key result

Dose descriptor:

NOAEL

Effect level:

99.6 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male/female

Basis for effect level:

other: fertility

Critical effects observed:

not specified

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Less frequently seen observation noted that all of the ZnCl2-treated males experienced hair loss behind the ears. Also, some females of the low- and high-dose groups had vaginal discharges.

Dermal irritation (if dermal study):

not specified

Mortality / viability:

mortality observed, treatment-related

Description (incidence and severity):

The males experienced 0, 12, 8, and 4% mortality in the control, low-, mid- and high-dose groups, respectively. The mortality among the F1 females was 0, 8, 12, and 20% in the control, low-, mid- and high-dose groups, respectively.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The F1 males in the mid- and high-dose groups experienced a significant reduction in body weight after the 1st week of dosing and the low-dose group experienced a similar reduction after the 2nd week of dosing. These trends continued up to the end of the experiment. The total weight gain of F1 males was significantly reduced (dose dependent) in the low, mid-, and high-dose groups. The body weights of pups at Day 21 in the high-dose group were significantly lower compared to their control.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

no effects observed

Description (incidence and severity):

ZnCl2-treatment to F0 and F1 males and females caused no significant effects on their feed efficiencies when compared to their control groups

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Description (incidence and severity):

There was a trend toward decreased values of Packed Cell Volume (PCV). In mid- and high-dose males of both generations, there seemed to a trend toward elevated values of Amyl, ALK, and GLu

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

The clinical chemistry findings in males and females of both generations did not show any significant difference from those of their controls

Urinalysis findings:

not specified

Sexual maturation:

not examined

Anogenital distance (AGD):

not specified

Nipple retention in male pups:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

In F1 males, the unadjusted weights of the brain, spleen, and prostate in all ZnCl2-treated groups, the liver, adrenal, testis and seminal vesicles in mid-dose and the kidney in high-dose were significantly different from their controls. When the organ weights of F1 males were adjusted for body weight, the brain, spleen, and prostate in all ZnCl2-treated groups, the liver, adrenal and seminal vesicles in mid-dose group, and kidney in high-dose group remained significantly different from their controls. The unadjusted organ weights of F1 females that were different from their controls included the brain and spleen in low- mid- and high-dose groups and the kidneys in the high-dose group. Following the adjustments of F1 female organ weights for body weight, the brain and spleen in all dose groups and kidneys in high dose groups were significantly different from controls.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Gross findings related to ZnCl2-treatment in males were primarily seen in the target organ systems (digestive, hematopoietic-lymphoreticular, and reproductive) already established for zinc. Digestive system lesions in the gastrointestinal tract (GIT) (distention, discoloration/hemorrhage and ulceration) and pancreas (smaller than usual) were mostly seen in rats given the two highest doses. Hematopoietic-lymphoreticular system lesions (small spleens and thymuses) were also scattered among the groups of ZnCl2-treated males. In the reproductive tract of the males, the only gross changes noted were small prostates and small seminal vesicles (one each) in the high-dose group. Gross lesions in ZnCl2-treated females generally paralleled those observed in their male counterparts.

Histopathological findings:

effects observed, treatment-related

Description (incidence and severity):

In males, the most biologically meaningful lesions were found in the reproductive system (prostatic acinar atrophy and inflammation) and the hematopoietic-lymphoreticular system (splenic lymphoid depletion and hemosiderosis and thymic atrophy) of 30.00 mg/kg/day ZnCl2-treated groups. These results indicated that ZnCl2 exposure has only mild effects on the reproductive performance of rats.
No significant changes in clinical pathology values or organ weights correlated with these lesions. None of the microscopic changes in target organs were of great magnitude. All unscheduled deaths were confined to the ZnCl2-treated groups, the majority of them probably being related to toxicity, but histomorphologic confirmation of this was not noted. The histopathology observed among the ZnCl2-treated females was similar to that seen in the males, except that no lesions were seen in the reproductive system. The correlations and biological interpretations were also very similar.

Other effects:

no effects observed

Description (incidence and severity):

Sex ratio F1: No significant difference was seen in the weaning index and sex ratios in F1 pups.
Reproductive performance F1: In F1 generation rats, ZnCl2 treatment resulted in a significant reduction on fertility, viability (Day 0) and litter size in the high-dose group compared to control. However, ZnCl2 treatment showed no effect on viability index, weaning index and sex ratios of F2 pups.

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

The most consistent finding was aggression/hyperactivity which was observed throughout the study in both Fo and F1 males and females of ZnCl2-treated groups

Developmental immunotoxicity:

not specified

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

49.8 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male/female

Basis for effect level:

other: general toxicity

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

99.6 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male/female

Basis for effect level:

other: fetotoxicity

Critical effects observed:

not specified

Reproductive effects observed:

not specified

Conclusions:

Under the test conditions, administration of test material to adult male and female rats throughout maturation, mating, gestation and early lactation resulted in significant effects on adults and offspring at 30 and 15 mg/kg/d. Although effects were seen at 7.5 mg/kg/d, these were considered to be toxicologically non significant and is therefore considered to be the "No Observed Adverse Effect Level" (NOAEL) for general toxicity. The NOAEL for fertility and fetotoxicity is 15 mg ZnCl2/kg bw/d.

The NOAEL(general toxicity) of ZnCl2 in rats was calculated to be 7.50 mg/kg bw/d (equivalent to 3.73 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL (general toxicity) corresponds to 49.8 mg/kg bw/d.
The NOAEL(fertility & fetotoxicity) of ZnCl2 in rats was calculated to be 15 mg/kg bw/d (equivalent to 7.47 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL (fertility & fetotoxicity) corresponds to 99.6mg/kg bw/d.

Executive summary:

A study was conducted to evaluate the reproductive toxicity potential of test material in rats for two generations.

Male and female rats were administered test material at the doses of 7.50, 15.00 and 30.00 mg/kg/d over two successive generations. Control group animals received deionised water. Exposure of F0 and F1 parental rats to test material showed significant reduction in fertility, viability (days 0 and 4), and the body weight of F1 and F2 pups from the high-dose group but caused no effects on weaning index, and sex ratio. Significant reduction in body weights of F0 and F1 parental males and postpartum dam weights female rats. Exposure of test material to Fo and F1 generation parental animals resulted in non significant change in clinical pathology parameters (except the ALK level). Reduction of brain, liver, kidney, spleen and seminal vesicles weights of males and in the spleen and uterus of females was observed in F0 and F1 rats. Gross lesions were observed in gastro-intestinal (GI) tract, lymphoreticular/ hematopoietic and reproductive tract in parental rats in both generations. Reduced body fat was also recorded in F1 parental rats.

Under the test conditions, administration of test material to adult male and female rats throughout maturation, mating, gestation and early lactation resulted in significant effects on adults and offspring at 30 and 15 mg/kg/d. Although effects were seen at 7.5 mg/kg/d, these were considered to be toxicologically non significant and is therefore considered to be the "No Observed Adverse Effect Level" (NOAEL). The NOAEL for fertility and fetotoxicity is 15 mg ZnCl2/kg bw/d.

The NOAEL (general toxicity) of ZnCl2 in rats was determined to be 7.50 mg/kg bw/d (equivalent to 3.73 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL(general toxicity) corresponds to 49.8mg/kg bw/d.

The NOAEL (reproductive toxicity & fetotoxicity) of ZnCl2 in rats was determined to be 15 mg/kg bw/d (equivalent to 7.47 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL(reproductive toxicity & fetotoxicity) corresponds to 99.6 mg/kg bw/d.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

100 mg/kg bw/day

Study duration:

subacute

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

EDDHA

In an one-generation reproduction toxicity study (NOTOX B.V., 1997), the closely related substance Fe(Na)EDDHMA (EC 405 -420 -1) in distilled water was administered to 28 Wistar rats/sex/dose level by single oral gavage (5 mL/kg bw) at dose levels of 50, 200 or 750 mg/kg bw/day (according to the OECD TG 415). A concurrent control group was treated with the vehicle only. Treatment commenced 10 weeks prior to mating for males and 2 weeks prior to mating for females and continued for both sexes until at least the end of the lactation period. Pregnant females were allowed to litter normally. On day 4 of lactation, each litter was adjusted to 4 males and 4 females or as near as possible. The surviving offspring was euthanized as soon as possible after weaning.

The primary effect of treatment with the test item on parental animals was poor physical condition, resulting in premature mortality, growth reduction and reduced food consumption in male and female animals at 750 mg/kg bw/day. These signs of test item-related toxicity were seen with reduced severity at 200 mg/kg bw/day in males only. Thus, the NOAEL for systemic toxicity in parental animals was 50 mg/kg bw/day under the conditions of this study.

In the offspring, increased post natal loss and reduced viability were noted during PND 0 -4 at 200 and 750 mg/kg bw/day, and with lower incidence at 50 mg/kg bw/day. With special regard to the low incidence and unusual distribution pattern of findings noted at 50 mg/kg bw/day, the NOAEL for developmental toxicity was 50 mg/kg bw/day under the conditions of this study.

Based on a slight decrease in the conception indices and a minimal delay in precoital time at 750 mg/kg bw/day, the NOAEL for reproductive performance/fertility was 200 mg/kg bw/day.

Zinc salts

gavage study in rats (Khan 2007)

A study was conducted to evaluate the reproductive toxicity potential of test material in rats for two generations. Male and female rats were administered test material at the doses of 7.50, 15.00 and 30.00 mg/kg/d over two successive generations. Control group animals received deionised water. Exposure of F0 and F1 parental rats to test material showed significant reduction in fertility, viability (days 0 and 4), and the body weight of F1 and F2 pups from the high-dose group but caused no effects on weaning index, and sex ratio. Significant reduction in body weights of F0 and F1 parental males and postpartum dam weights female rats. Exposure of test material to Fo and F1 generation parental animals resulted in non significant change in clinical pathology parameters (except the ALK level). Reduction of brain, liver, kidney, spleen and seminal vesicles weights of males and in the spleen and uterus of females was observed in F0 and F1 rats. Gross lesions were observed in gastro-intestinal (GI) tract, lymphoreticular/ hematopoietic and reproductive tract in parental rats in both generations. Reduced body fat was also recorded in F1 parental rats. Under the test conditions, administration of test material to adult male and female rats throughout maturation, mating, gestation and early lactation resulted in significant effects on adults and offspring at 30 and 15 mg/kg/d. Although effects were seen at 7.5 mg/kg/d, these were considered to be toxicologically non significant and is therefore considered to be the "No Observed Adverse Effect Level" (NOAEL). The NOAEL for fertility and fetotoxicity is 15 mg ZnCl2/kg bw/d.

The NOAEL(general toxicity) of ZnCl2 in rats was determined to be 7.50 mg/kg bw/d (equivalent to 3.73 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL (general toxicity) corresponds to 49.8 mg/kg bw/d.

The NOAEL (reproductive toxicity & fetotoxicity) of ZnCl2 in rats was calculated to be 15 mg/kg bw/d (equivalent to 7.47 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL (reproductive toxicity & fetotoxicity) corresponds to 99.6 mg/kg bw/d.

feeding study in rats (Pal and Pal 1987)

Anhydrous ZnSO4 was used to test the influence of zinc feeding on conception of rats. Two tests were conducted involving the dosing of female, virgin rats with zinc administration starting either after coitus (test 1) or already 21 to 26 days prior to mating (test 2). In both tests the dosage was continued during the pregnancy until the female rats were sacrificed on day 18 of gestation. Weight of the placenta was not significantly different between the experimental group and their respective control group. Regarding test 1, 12 out of 15 animals of the control group and the treated group were mated, of which 12 and 5 females, respectively, conceived during the study.

In test 2 11 out of 18 animals of the control group and 15 out of 18 animals of the treated group were mated, of which 10 and 14 females, respectively, conceived during the study. So, in test 2 there was no significant difference in incidence of conception between the treated group and the control group.

In test 1 the implanation sites per pregnant female was lower in the zinc treated group (5.0) than in the control rats (7.0), however the difference was not significant (t-test). Implantation sites per mated female were 7.0 in the control group and 2.1 in the zinc fed experimental group. This difference was statistically significant.

In test 2 there was no significant difference between the two groups regarding implantation sites expressed per mated or pregnant female. In both tests no significant difference in the mean fetal and placental weights were identified and no stillbirth or malformation of the fetuses for either of the tests was detected.  

For the female parent, the dose of 4000 ppm zinc showed either no effects (in case of dosage start prior to mating) or a slight effect on reproduction performance (in case of dosage started after coitus). However, the dose of 4000 ppm (= 200 mg/kg bw/day) was regarded as NOAEL as the test design of test 2 (start of dosage prior to mating) is more closely to accepted standard methods (i.e. OECD Guideline 421). For the F1 generation (examination of fetuses) no effect of the dosage of the female parent animal was observed.

The dosage of 4000 ppm zinc corresponds to a target substance concentration of 53333 ppm and 2667 mg/kg bw/day.

gavage study in rats (Johnson 2011)

Reproductive and developmental toxicities of zinc supplementation in F0 rats and F1 progeny were examined. Rats were treated by gavaging with zinc chloride (ZnCl2) at 0.0, 7.5, 15 and 30 mg/kg-d. ZnCl2 treatment was associated with deficient energy imbalances, reduced number of live pups/litter, decreased live birth index, increased mortality and increased fetal resorption. Pregnant females supplemented with 15 or 30 mg/kg-d ZnCl2, gained significantly less weight and had reduced feed conversion efficiency during gestation. This suggests that excess ZnCl2 supplementation is associated with impaired or suppressed appetite during fetal development and may have contributed to a reduction in pregnancy outcomes. In fact, the total number of pups, pups per litter and live pups per litter were significantly reduced in all ZnCl2 supplemented dams. In the case of females exposed to 7.5 mg/kg-d ZnCl2, the number of stillbirths was not significant; however, the implantation efficiency was significantly reduced. In contrast, medium and high ZnCl2 dosages were associated with a significant increase in the number of pups born dead, without affecting implantation efficiency. These results suggest that low ZnCl2 supplementation increased the rate of fetal resorption, whereas more moderate and high ZnCl2 dosages increased the rate of stillbirths. Changes in serum clinical chemistry and hematologic parameters were sex-related. In F0 females, ZnCl2 was associated with increased liver/body weight ratios, reduced creatinine and reduced alkaline phosphatase concentrations. In F0 males, ZnCl2 significantly increased relative liver weight and elevated gamma-GGT. In addition, at birth, F1 males exhibited, a significant (p< 0.05) increase in anogenital distance, whereas ZnCl2 hastened the time of eye opening and incisor eruption in males and females.

Effects on developmental toxicity

Description of key information

There is no data available for the registered substance on developmental toxicity. However, there is data available for the source substances FeNaEDDHA and zinc salts.

Fe(Na)EDDHA

OECD 414, GLP, oral, rats, NOEL = 500 mg/kg bw/day based on the absence of embryo-/foetotoxic or teratogenic effects in the highest dose group

Zinc chloride

Two generation study, oral gavage, rat, NOAEL (fetotoxicity) = 15 mg/kg bw/day was determined for ZnCl2. These NOAELs was converted to the target substance taking into account the Zn content of 7.5 % leading to NOAEL (fetotoxicity) = 99.6 mg/kg bw/day.

Further information can be found under 'Additional information'.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Species:

rat

Strain:

other: Sprague-Dawley derived; Tif:RAIf (SPF); hybrids of RII/1 x RII/2

Clinical signs:

no effects observed

Description (incidence and severity):

There were no treatment-related clinical signs in this study.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

There were no treatment-related deaths in this study. One dam in the mid dose group was sacrificed moribund on day 11 p.c.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

There were no significant differences in mean maternal body weights between groups at any time during the study.
Maternal body weight gain was statistically significantly reduced in the 500 mg/kg group during the second half of the dosing period (days 11 to 16 p.c.). Body weight gain was unaffected by treatment in the 5 and 100 mg/kg groups.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

At 500 mg/kg, there was a statistically significant reduction in food consumption during the second half of the dosing period (days 11 to 16 p.c.). At 5 and 100 mg/kg, values for food consumption were similar to those of the control group throughout the study.

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

Mean carcass weight and gravid uterus weights were not affected by treatment. Net body weight gain was significantly reduced in the 500 mg/kg group.

Gross pathological findings:

no effects observed

Description (incidence and severity):

No macroscopic findings were noted at necropsy of the dams on day 21 p.c.

Number of abortions:

no effects observed

Description (incidence and severity):

There were no dead or aborted fetuses. The number of live fetuses per litter and fetal weights were not affected by treatment.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

Preimplantation losses and early and late postimplantation losses were comparable between groups.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

Preimplantation losses were comparable between groups.

Early or late resorptions:

no effects observed

Description (incidence and severity):

Preimplantation losses were comparable between groups.

Dead fetuses:

no effects observed

Description (incidence and severity):

There were no dead or aborted fetuses. The number of live fetuses per litter and fetal weights were not affected by treatment.

Changes in number of pregnant:

effects observed, non-treatment-related

Description (incidence and severity):

Of the 24 mated animals per group, three, one and three were not pregant in the low, mid and high dose groups, respectively. Thus the number of pregnant animals per group was 24, 21, 23 and 21, respectively. One dam in the mid dose group was sacrificed moribund on day 11 p.c. At necropsy, the number of dams per group with viable fetuses was therefore 24, 21, 22, and 21, respectively.

Details on maternal toxic effects:

There was a reduction in mean food consumption and body weight gain during the second half of the dosing period at 500 mg/kg bw/day.

Dose descriptor:

NOEL

Effect level:

100 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Abnormalities:

not specified

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Mean fetal body weights were not affected by treatment.

Changes in sex ratio:

no effects observed

Description (incidence and severity):

Fetal sex ratios were not affected by treatment.

External malformations:

no effects observed

Description (incidence and severity):

There were no treatment-related external fetal abnormalities.

Skeletal malformations:

effects observed, non-treatment-related

Description (incidence and severity):

There were no treatment-related skeletal malformations. Incidental malformations were seen in two control fetuses (no. 13/3: runt, and no. 5/1: umbilical hernia) and one low dose group fetus (no. 33/3: generalized edema, cleft lower jaw and cleft palate). The overall incidence of external, visceral and skeletal anomalies and variations were not affected by treatment.

Visceral malformations:

effects observed, non-treatment-related

Description (incidence and severity):

No treatment-related findings were observed. Incidental malformations were seen in two control fetuses (no. 13/3: runt, and no. 5/1: umbilical hernia) and one low dose group fetus (no. 33/3: generalized edema, cleft lower jaw and cleft palate). The overall incidence of external, visceral and skeletal anomalies and variations were not affected by treatment.

Details on embryotoxic / teratogenic effects:

There was no indication for test item related embryotoxicity or teratogenic effects under the conditions of this study.

Dose descriptor:

NOEL

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: teratogenicity

Abnormalities:

no effects observed

Developmental effects observed:

no

Chemical Analysis

Administration / Treatment 1:

The mean concentrations of the test item in the vehicle were 88.1 % (0.5 mg/mL) , 94.0 % (10 mg/mL) and 93.3 % (50 mg/mL) of the nominal concentrations for the low mid and high dose groups, respectively. The homogeneity varied in the range from -2 % to 4 % of the mean concentration. The test item was stable in the vehicle.

Administration / Treatment 2:

The mean concentrations of the test item in the vehicle were 94.9 % (0.5 mg/mL) , 93.9 % (10 mg/mL) and 94.1 % (50 mg/mL) of the nominal concentrations for the low mid and high dose groups, respectively. The homogeneity varied in the range from -1 % to 1 % of the mean concentration. The test item was stable in the vehicle.

Conclusions:

Evidence of maternal toxicity, in terms of reduced body weight gain and reduced food consumption, was observed in the high dose group (500 mg/kg). No adverse effects on pregnancy or fetal parameters were observed. On the basis of the results obtained in this study, the no observed effect level (NOEL) was 100 mg/kg body weight/day for the dams and 500 mg/kg body weight/day for the progeny. There was no indication of teratogenic potential. The same result is expected for the target substance since it has the same constituents that act via the same mechanism as the source substance. No differences in the magnitude of the effects are expected. Therefore, the same NOEL is expected also for the target substance.

Executive summary:

In a developmental toxicity study FeNaEDDHA was administered once daily to groups of 24 mated female Sprague-Dawley derived rats by oral gavage at dose levels of 5, 100 or 500 mg/kg bw/day (10 mL/kg bw) from day 6 through day 15 of gestation. Control group females received the vehicle, 0.5 % (w/w) CMC in distilled water, only. The nominal concentrations, homogeneity and stability of the test item in the vehicle were confirmed by chemical analysis of dose formulations. All dams were sacrificed on day 21 of the gestation period and foetuses removed for examination. In dams, there were no treatment-related clinical signs or incidences of mortality. The body weight gain was reduced at 500 mg/kg bw/day for the period of day 6 -16 of gestation, and reduced food consumption was also noted at this dose level. No adverse effects on pregnancy and no embryo-/foetotoxic effects were observed. There was no indication of teratogenic potential. On the basis of these results, the NOEL was 100 mg/kg bw/day for maternal toxicity and 500 mg/kg bw/day for developmental toxicity and teratogenicity.

The developmental toxicity study in the rat is classified as acceptabel and satisfies the requirements of test guideline OECD 414.

Reference 2

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to Read Across Statement attached in Section 13

Reason / purpose for cross-reference:

read-across source

Species:

rat

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Aggression/hyperactivity throughout the study in both males and females, hair loss behind the ears in males, vaginal discharges in low and high dose females; 0-20 and 12-24 % mortality in males and females respectively.

Dermal irritation (if dermal study):

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

The males experienced 0, 8, 20, and 12% mortality in control, low-, mid- and high-dose groups, respectively. The mortality among the females was 12, 24, 28, and 24% for the control, low-, mid- and high-dose groups, respectively. All unscheduled deaths were confined to the ZnCl2-treated groups, the majority of them probably being related to toxicity, but histomorphologic confirmation of this was not noted.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

All ZnCl2-treated F0 males experienced significant reduction in body weight after the 1st week of dosing and this trend continued up to the end of the experiment. The total weight gain of males was significantly reduced (dose dependent) in the low-, mid- and high-dose groups. In the F0 females, total weight gain and percent reduction in the low- mid- and high-dose groups were not significantly different from the control.
Postpartum dam body weight: The F0 and F1 post-partum dam weights in all dose groups were significantly different from their control groups.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

no effects observed

Description (incidence and severity):

ZnCl2-treatment to F0 and F1 males and females caused no significant effects on their feed efficiencies when compared to their control groups

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Description (incidence and severity):

None of the hemogram or leukogram values of both Fo and F1 males and females among the ZnCl2-treated groups were different from those of the control groups. However, there was a trend toward decreased values of Packed Cell Volume (PCV). The clinical chemistry findings in males and females of both generations did not show any significant difference from those of their controls. However, in mid- and high-dose males of both generations, there seemed to a trend toward elevated values of Amyl, ALK, and GLu.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

The clinical chemistry findings in males and females of both generations did not show any significant difference from those of their controls

Endocrine findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

The most consistent finding was aggression/hyperactivity which was observed throughout the study in both Fo and F1 males and females of ZnCl2-treated groups.

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

In F0 males, the unadjusted weights of the brain in the mid- and high-dose groups, the liver and kidney in all ZnCl2-treated groups, the spleen in the high-dose group, and the seminal vesicles in the mid- and high-dose groups were significantly different from the control. When organ weights of F0 males were adjusted for body weight, the brain in the mid- and high-dose groups, the liver and kidney in all ZnCl2-treated groups, the spleen in the high-dose group, and the seminal vesicles in the mid- and high-dose groups remained significantly different from their controls. The unadjusted organ weights of F0 females revealed significant differences for the spleen and uterus in the high-dose group. Following the adjustments of F0 female organ weights for body weight, the spleen and the uterus in the high-dose group remained significantly different from their controls.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Gross findings related to ZnCl2-treatment in males were primarily seen in the target organ systems (digestive, hematopoietic-lymphoreticular, and reproductive) already established for zinc. Digestive system lesions in the gastrointestinal tract (GIT) (distention, discoloration/hemorrhage and ulceration) and pancreas (smaller than usual) were mostly seen in rats given the two highest doses. Hematopoietic-lymphoreticular system lesions (small spleens and thymuses) were also scattered among the groups of ZnCl2-treated males. In the reproductive tract of the males, the only gross changes noted were small prostates and small seminal vesicles (one each) in the high-dose group. Gross lesions in ZnCl2-treated females generally paralleled those observed in their male counterparts.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

In both Fo and F1 males, the most biologically meaningful lesions were found in the reproductive system (prostatic acinar atrophy and inflammation) and the hematopoieticlymphoreticular system (splenic lymphoid depletion and hemosiderosis and thymic atrophy) of ZnCl2-treated groups (data are not shown). No significant changes in clinical pathology values or organ weights correlated with these lesions. None of the microscopic changes in target organs were of great magnitude. All unscheduled deaths were confined to the ZnCl2-treated groups, the majority of them probably being related to toxicity, but histomorphologic confirmation of this was not noted. The histopathology observed among the ZnCl2-treated females of both Fo and F1 generations was similar to that seen in the males, except that no lesions were seen in the reproductive system. The correlations and biological interpretations were also very similar.

Histopathological findings: neoplastic:

no effects observed

Other effects:

not examined

Number of abortions:

not specified

Pre- and post-implantation loss:

not specified

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

not specified

Changes in pregnancy duration:

not specified

Changes in number of pregnant:

not specified

Details on maternal toxic effects:

The F0 and F1 post-partum dam weights in all dose groupswere significantly different from their control groups. In F0 rats, ZnCl2 treatment caused a significant reduction on the fertility, litter size, and the viability indices (days 0 and 4) were significantly reduced at the high-dose group compared to control.

Dose descriptor:

NOAEL

Remarks:

general toxicity

Effect level:

49.8 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Basis for effect level:

behaviour (functional findings)

body weight and weight gain

gross pathology

histopathology: non-neoplastic

mortality

Key result

Dose descriptor:

NOAEL

Effect level:

99.6 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Basis for effect level:

other: fertility, litter size, and the viability indices

Abnormalities:

not specified

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

The body weight of F2 pup at day 21 in the high-dose group were significantly lower compared to the control.

Reduction in number of live offspring:

effects observed, treatment-related

Description (incidence and severity):

In high dose group, live birth index is significantly different from control groups.

Changes in sex ratio:

no effects observed

Description (incidence and severity):

However, no significant difference was seen in the weaning index and sex ratios F1 pups.

Changes in litter size and weights:

effects observed, treatment-related

Description (incidence and severity):

ZnCl2 treatment caused a significant reduction on the fertility, litter size, and the viability indices (days 0 and 4) were significantly reduced at the high-dose group compared to control

Anogenital distance of all rodent fetuses:

not specified

Changes in postnatal survival:

not specified

External malformations:

not specified

Skeletal malformations:

not specified

Visceral malformations:

not specified

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

99.6 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

fetal/pup body weight changes

changes in litter size and weights

Abnormalities:

not specified

Developmental effects observed:

no

Conclusions:

Under the test conditions, administration of test material to adult male and female rats throughout maturation, mating, gestation and early lactation resulted in significant effects on adults and offspring at 30 and 15 mg/kg/d. Although effects were seen at 7.5 mg/kg/d, these were considered to be toxicologically non significant and is therefore considered to be the "No Observed Adverse Effect Level" (NOAEL) for general toxicity. The NOAEL for fertility and fetotoxicity is 15 mg ZnCl2/kg bw/d.

The NOAEL (fetotoxicity) of ZnCl2 in rats was calculated to be 15 mg/kg bw/d (equivalent to 7.47 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL (fetotoxicity) corresponds to 99.6 mg/kg bw/d.

Executive summary:

A study was conducted to evaluate the reproductive toxicity potential of test material in rats for two generations. Male and female rats were administered test material at the doses of 7.50, 15.00 and 30.00 mg/kg/d over two successive generations. Control group animals received deionised water. Exposure of parental group to test material showed significant reduction in fertility, viability (days 0 and 4). The offspring showed changes in litter sizes, the body weight and reduction of number of live offspring in the high-dose. No abnormality was observed in offspring group. Therefore NOAEL for fetotoxicity was determined 15 mg/kg bw/d and no developmental toxicity observed.

The NOAEL(fetotoxicity) of ZnCl2 in rats was calculated to be 15 mg/kg bw/d (equivalent to 7.47 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL (fetotoxicity) corresponds to 99.6 mg/kg bw/d.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

100 mg/kg bw/day

Study duration:

subacute

Species:

rat

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

EDDHA

In a developmental toxicity study (CIBA-GEIGY, 1995; Report No. 941105), the source substance Fe(Na)EDDHA (CAS 84539 -55 -9) was administered once daily to groups of 24 mated female Sprague-Dawley derived rats by oral gavage at dose levels of 5, 100 or 500 mg/kg bw/day (10 mL/kg bw) from day 6 through day 15 of gestation (according to the OECD Guideline 414). Control group females received the vehicle, 0.5 % (w/w) CMC in distilled water, only. The nominal concentrations, homogeneity and stability of the test item in the vehicle were confirmed by chemical analysis of dose formulations. All dams were sacrificed on day 21 of the gestation period and foetuses removed for examination. In dams, there were no treatment-related clinical signs or incidences of mortality. The body weight gain was reduced at 500 mg/kg bw/day for the period of day 6 -16 of gestation, and reduced food consumption was also noted at this dose level. No adverse effects on pregnancy and no embryo-/foetotoxic effects were observed. There was no indication of teratogenic potential. On the basis of these results, the NOEL was 100 mg/kg bw/day for maternal toxicity and 500 mg/kg bw/day for developmental toxicity and teratogenicity.

 

Zinc chloride (Khan 2007)

A study was conducted to evaluate the reproductive toxicity potential of test material in rats for two generations. Male and female rats were administered test material at the doses of 7.50, 15.00 and 30.00 mg/kg/d over two successive generations. Control group animals received deionised water. Exposure of parental group to test material showed significant reduction in fertility, viability (days 0 and 4). The offspring showed changes in litter sizes, the body weight and reduction of number of live offspring in the high-dose. No abnormality was observed in offspring group. Therefore, the NOAEL for fetotoxicity was determined 15 mg/kg bw/d and no developmental toxicity observed.

The NOAEL (fetotoxicity) of ZnCl2 in rats was calculated to be 15 mg/kg bw/d (equivalent to 7.47 mg of Zn/kg bw/d). Considering the Zn concentration of max. 7.5 % in the target substance, the NOAEL (fetotoxicity) corresponds to 99.6 mg/kg bw/d.

Zinc sulfate

Female CD-1 mice (25-30 animals/group) received daily doses of 0.3, 1.4, 6.5 and 30 mg unspecified ZnSO4/kg bw by gavage during days 6-15 of gestation. A control group was included. All animals were observed daily for appearance and behaviour with particular attention to food consumption and body weight. Body weights were recorded on day 0, 6, 11, 15 and 17 of gestation. The females were sacrificed at day 17. The urogenital tract of each animal was examined in detail.

No clearly discernible effects on maternal survival, body weight gains, number of corpora lutea, implantations and resorptions were observed. The number of live litters, live and dead foetuses, the foetus weights and sex ratio were not affected by treatment. No difference in number or kind of abnormalities (in either soft or skeletal tissues) was found between exposed and control groups.

Under the conditions of the test, administration of up to 30 mg/kg bw of unspecified zinc sulphate (ca.12 mg or 6.8 mg Zn2+/kg bw, for anhydrate and heptahydrate, respectively) had no adverse effects on adult mice and their foetuses. Considering the Zn concentration of max. 7.5 % in the target substance, the maximum no adverse effect level of the target substance was determined to be 162 mg/kb bw/d assuming that the test item was anhydrous ZnSO4 (FDRL 1973).

Female Dutch rabbits (14-19 animals/group) received daily doses of 0.6, 2.8, 13 and 60 mg unspecified ZnSO4/kg bw/d by gavage during days 6-18 of gestation. A control group was included. All animals were observed daily for appearance and behaviour with particular attention to food consumption and body weight. Body weights were recorded on day 0, 6, 12, 18 and 29 of gestation. The urogenital tract of each animal was examined in detail. The females were sacrificed at day 29. Between 10 and 12 females were pregnant at term in all groups.

No clearly discernible effects on maternal survival, body weight gains, number of corpora lutea, implantations and resorptions were observed. The number of live litters, live and dead foetuses, the foetus weights and sex ratio were not affected by treatment. No difference in number or kind of abnormalities (in either soft or skeletal tissues) was found between exposed and control groups.

Under the conditions of the test, administration of up to 60 mg/kg bw of unspecified zinc sulphate (ca. 24 mg or 13.6 mg Zn2+/kg bw, for anhydrate and heptahydrate, respectively) had no adverse effects on adult rabbits and their foetuses.

Considering the Zn concentration of max. 7.5 % in the target substance, the maximum no adverse effect level of the target substance was determined to be 324 mg/kb bw/d assuming that the test item was anhydrous ZnSO4 (FDRL 1974).

Justification for classification or non-classification

Based on the findings in the available studies, the test item needs not to be classified according to Regulation (EC) No 1272/2008.