Zinc EDDHA

Endpoint summary

Description of key information

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

The value for the zinc salt was converted to the registered substance under consideration of the maximum percentage of zinc included in the substance. The key value for zinc is based on a 13 week repeated dose toxicity study in rats and mice (Maita 1981). The lowest NOAEL in this study was determined in males rats. Converted to the target substance this value corresponds to 711 mg/kg bw/day for the zinc moiety of the target substance.

For Fe(Na)EDDHA a NOAEL of 10 mg/kg bw/day is calculated from the subchronic oral toxicity study in rats (Novartis Crop Protection AG, 1998).

Further information can be found under 'Additional information'.

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

short-term repeated dose toxicity: oral

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

Clinical signs:

no effects observed

Description (incidence and severity):

There were no test item related clinical findings.

Mortality:

no mortality observed

Description (incidence):

No deaths occurred.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Mean body weight was reduced and there was a mean body weight gain depression at 200 and 1000 mg/kg bw/day.
Compared to the control group, the body weight development of animals in groups 3 and 4 (200 and 1000 mg/kg) was impaired. At week 4, the mean weights of group 4 (1000 mg/kg bw) were 25% (males) and 22% (females), and the mean body weight gains (week -1 to week 4) 44% (males) and 54% (females) below that of the control group, respectively. The mean body weights of group 3 (200 mg/kg bw) were 6% (males) and 11% (females), and the mean body weight gains 11% (males) and 27% (females) below that of the control group, respectively. Body weight development in group 2 (50 mg/kg bw) was not affected by treatment.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Overall food consumption (week 1 to 4) was reduced by 29% in males and 26% in females of group 4 (1000 mg/kg bw), and by 10% in males and 8% in females of group 3 (200 mg/kg bw).

Food efficiency:

not examined

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

effects observed, treatment-related

Description (incidence and severity):

The mean water consumption was markedly increased at 1000 mg/kg bw/day.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Anaemia was observed at 200 and 1000 mg/kg bw/day: "It was accompanied by a slight hyperchromasia of red blood cells. The release of reticulocytes from erythropoietic organs was not increased, suggesting a lack of an adaptive response. Furthermore, males of group 4 (1000 mg/kg bw) had slightly lower values of white blood cells, predominantly of lymphocytes and basophils. In addition, males of groups 3 and 4 (200 mg/kg bw and 1000 mg/kg bw) had minimally higher platelet counts. Slightly lower values of prothrombin time, as recorded for males of group 2 (50 mg/kg), and for animals of groups 3 and 4 (200 and 1000 mg/kg bw) are considered without toxicological relevance".

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Minimal or slight changes in several clinical chemistry parameters were noted at 1000 mg/kg bw/day. Minimally increased creatinine concentrations were observed in males at 200 mg/kg bw/day:
"Plasma creatinine concentrations were minimally increased in males of group 3 (200 mg/kg) and slightly increased in males and females of group 4 (1000 mg/kg). In group 4 (1000 mg/kg bw), plasma cholesterol levels were slightly increased in males and females and plasma potassium concentrations were decreased in females. Furthermore, in the high dose group (1000 mg/kg) plasma bilirubin levels were increased in males, plasma albumin concentrations were minimally elevated and plasma globulins were minimally decreased in females, resulting in an increased A/G ratio".

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Excretion of a larger amount of reddish discoloured urine and mild bilirubinuria were observed in males at 1000 mg/kg bw/day. There was no evidence that treatment with the test article had affected other urine parameters investigated.

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

The mean body weight relative weights of the heart, kidneys, adrenals and spleen were changed at 200 and/or 1000 mg/kg bw/day as compared to the concurrent control group:
"At necropsy the mean carcass weight was decreased in group 3 (200 mg/kg; males -8%, females -10%) and in group 4 (1000 mg/kg; males -27%, females -23%), compared to that of the control group.
Heart to body weight ratio was significantly increased in males of group 3 (+12%) and group 4 (+30%), and in females of group 4 (+18%). Kidney to body weight ratio was increased in males of group 3 (+12%) and group 4 (+51%), and in females of group 4 (+31%). Adrenal to body weight ratio was increased in males of group 2 (+11%), group 3 (+13%) and group 4 (+28%). Spleen to body weight ratio was increased in females of group 4 (+24%).
Changes in absolute organ weights of liver, thymus, adrenals, testis and spleen, which attained statistical significances in group 4, are considered consequent to the body weight decrease in this group, and are therefore of no toxicological relevance. Other differences which attained a level of statistical significance were dose-independent and, therefore, not considered of experimental relevance".

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no test item related macroscopical findings.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Microscopical examination revealed cytoplasmic vacuolisation of cortical tubules of the kidneys at 1000 mg/kg bw/day:
"On morphological grounds this lesion was compatible with osmotic nephrosis (C. Gopinath et al, 1987) which is known to be induced in rats by hypertonic sugar solutions including dextran and some chelating agents (P. Greaves, 1990)".

Histopathological findings: neoplastic:

not specified

Dose descriptor:

NOAEL

Basis for effect level:

other: This study was a range finding study for a 90-day repeated dose oral toxicity study (Novartis Crop Protection AG, 1998). The latter study was used for NOEL derivation.

Remarks on result:

not measured/tested

Remarks:

no NOAEL identified

Critical effects observed:

not specified

CHEMICAL ANALYSIS OF DOSE FORMULATIONS

The calculated mean contents of the test item in the dose formulations used for the low, mid and high dose groups were 105, 112 and 107 % of the nominal concentrations, respectively.

Conclusions:

No NOAEL is identified. This study was used as scientific basis for dose level selection for a subsequent 90 -day repeated dose oral toxicity study in the rat. The same result is expected for the organic constituents of target substance since it has the same composition as the source substance.

Executive summary:

In a dose range-finding subacute oral toxicity study (CIBA-GEIGY Limited, 1996), FeNaEDDHA in 0.5 % CMC and 0.1 % Tween 80 in distilled water was administered to 5 Sprague-Dawley derived rats/sex/dose level by oral gavage (10 mL/kg bw) at dose levels of 50, 200 or 1000 mg/kg bw/day for a period of 28 days. Male and female animals of the concurrent control group were treated with the vehicle only. Treatment with the test item resulted in impaired body weight development of rats treated at 200 and 1000 mg/kg bw/day and correspondent lower food intake. An anaemia without erythropoietic response was noted at 200 and 1000 mg/kg bw/day. At the same dose levels, the kidney was revealed as target organ by microscopical examination, by blood chemistry data and by organ weight evaluation. In addition, body weight relative organ weight changes were noted in the heart, adrenals and spleen. However, the relevance of these findings was considered as equivocal. This study was used as scientific basis for dose level selection for a subsequent 90 -day repeated dose oral toxicity study in the rat.

This subacute oral toxicity study in the rat is acceptable and satisfies the requirement for test guideline OECD 407.

Reference 2

Endpoint:

sub-chronic toxicity: oral

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:

no effects observed

Description (incidence and severity):

During this study neither changes to the behavior nor relevant clinical signs were observed.

Mortality:

no mortality observed

Description (incidence):

There was no mortality during this study which was attributed to the treatment with the test article. In the third treatment week one female animal (no. 86) died. However, there were no indications of a test article-related occurrence.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Decreased mean body weights were noted from weeks 5 and 8 onwards at 200 mg/kg bw/day in male and female rats, respectively. The mean body weight gains were decreased by the end of the treatment period in animals treated with 200 mg/kg bw/day. During the recovery period, body weight gain in animals previously treated with 200 mg/kg bw/day was higher as compared to controls.
The body weight development in the other treated groups was not influenced by treatment.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption and food consumption ratios were decreased at 200 mg/kg bw/day in both sexes (decreased food consumption of 13% in males and of 8% in females, compared to the controls). During the recovery period food intake improved.
The mean food consumption of the other treated groups was not influenced by treatment.

Food efficiency:

not examined

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

no effects observed

Description (incidence and severity):

The mean water consumption was not influenced by treatment.

Ophthalmological findings:

no effects observed

Description (incidence and severity):

The examinations of the eyes (lids and surrounds, conjunctiva, pupillary reflex, cornea, sclera, anterior chamber, lens, vitreous, and fundus) towards treatment end (day 87) and towards recovery end (day 115) did not reveal any treatment-related findings.

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

At the end of the treatment period, a normochromic anaemia with lower erythrocyte count, haemoglobin concentration and haematocrit was observed in males and females at 200 mg/kg bw/day and males at 50 mg/kg bw/day. A higher reticulocyte count associated with higher MCV and MCH values and reduced white blood cell, basophil, lymphocyte and monocyte counts were confined to males at 200 mg/kg bw/day. A higher platelet count was recorded for males at 50 and 200 mg/kg bw/day and a higher prothrombin activity was recorded for males and females at 200 mg/kg bw/day. Evidence of reversibility for all the above parameters was apparent after the recovery period.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Several clinical chemistry parameters including creatinine, urea, protein, globulin, cholesterol and sodium concentration were increased at 50 and/or 200 mg/kg bw/day. Lower potassium levels were noted in males at 200 mg/kg bw/day. All values were similar to the control group values after the 4-week recovery period.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Excretion of more acidic red-brown (males) or yellow-brown (females) discoloured urine was observed at 200 mg/kg bw/day. More acidic urine was also excreted by males at 50 mg/kg bw/day. By the end of the recovery period, the colour and pH of the urine excreted by male and females previously treated at 200 mg/kg bw/day was similar to that of control group animals.

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

The mean carcass weights were decreased at the end of the treatment period at 200 mg/kg bw/day. Males at 200 mg/kg bw/day showed an elevated mean heart to body weight ratio which still was higher than the concurrent control value at the end of the recovery period.

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no test item related findings.

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

There were no test item related findings.

Histopathological findings: neoplastic:

not specified

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: haematology parameters (anaemia) The NOAEL was estimated based on the LOAEL of 50 mg/kg bw/day applying an assessment factor of 5.

Critical effects observed:

not specified

CHEMICAL ANALYSIS OF DOSE FORMULATIONS

The calculated overall mean contents of the test item in the dose formulations used for the low, mid and high dose groups were 96.9, 104.2 and 101.0 % of the nominal concentrations, respectively (RCC project no. 651688). In a previous 28 -day dose range finding study with the same test item and vehicle, the stability and homogeneity of dose formulations were within the limits of acceptance (RCC project no. 393322).

Estimation of NOAEL:

A more realistic NOAEL was estimated from the LOAEL of 50 mg/kg bw/day applying an assessment factor of 5. This method is applicable and scientifically justified for this test, as only slight adverse effects were observed at 50 mg/kg bw/day (haematology parameters - anaemia). To take the relatively large concentration gap between 5 (clear NOEL) and 50 mg/kg bw/day into account, 5 mg/kg bw/day was not taken as NOAEL, but extrapolated form the LOAEL. The guidance on information requirements and CSA, R.8 (ECHA, 2008 -2010) recommends a factor between 3 and 10 for extrapolation from LOAEL to NOAEL. An assessment factor of 5 seems to be approprate and conservative enough for the current study as only slight effects were observed at the LOAEL of 50 mg/kg bw/day.

Conclusions:

NOEL of 5 mg/kg bw was established in this study (for males and females). NOAEL of 10 mg/kg bw was derived based on LOAEL of 50 mg/kg bw. The same result is expected for the organic constituents of target substance since it has the same composition as the source substance.

Executive summary:

In a subchronic toxicity study (Novartis Crop Protection AG, 1998), FeNaEDDHA in 0.5 % CMC and 0.1 % Tween 80 in distilled water was administered to 10 Sprague-Dawley derived rats/sex/dose level by oral gavage (10 mL/kg bw) at dose levels of 5, 50 or 200 mg/kg bw/day for a period of 90 days. Male and female animals of the concurrent control group were treated with the vehicle only. Additional 10 animals/sex of the high dose and control group were kept on control diet for a 4 -week recovery period before sacrifice. Treatment with the test item resulted in lower food intake and impaired body weight development of rats treated at 200 mg/kg bw/day. Reversible effects on the red blood cell (normochromic anaemia) and white blood cell parameters, and higher values of platelets and prothrombin activity were noted at 50 and/or 200 mg/kg bw/day. In addition, there were changes of blood chemistry and urine parameters concerning the liver and kidneys. The body weight relative heart weight was increased in males at 200 mg/kg bw/day. Under the conditions of this study, the NOAEL for FeNaEDDHA when administered by daily oral gavage for three months was 10 mg/kg bw/day (estimated from the LOAEL).

This subchronic toxicity study in the rat is acceptable and satisfies the guideline requirement for a subchronic oral study (OECD 408).

Estimation of NOAEL:

A more realistic NOAEL was estimated from the LOAEL of 50 mg/kg bw/day applying an assessment factor of 5. This method is applicable and scientifically justified for this test, as only slight adverse effects were observed at 50 mg/kg bw/day (haematology parameters - anaemia). To take the relatively large concentration gap between 5 (clear NOEL) and 50 mg/kg bw/day into account, 5 mg/kg bw/day was not taken as NOAEL, but extrapolated form the LOAEL. The guidance on information requirements and CSA, R.8 (ECHA, 2008 -2010) recommends a factor between 3 and 10 for extrapolation from LOAEL to NOAEL. An assessment factor of 5 seems to be approprate and conservative enough for the current study as only slight effects were observed at the LOAEL of 50 mg/kg bw/day. Consequently a NOAEL of 10 mg/kg bw/day is calculated for this study.

Reference 3

Endpoint:

sub-chronic toxicity: oral

Type of information:

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

Adequacy of study:

weight of evidence

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 mice, dead or moribund animals in the 30000 ppm group showed depressed spontaneous motility and unkempt fur a little while before death or sacrifice.

Mortality:

mortality observed, treatment-related

Description (incidence):

In mice, four males and one female in the 30000 ppm group were found dead or killed in extremis during the study. Mortality was 33.3% in males and 8.3% in females

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Mice of both sexes in the 30000 ppm group showed a more prominently retarded growth resulting in smaller body size than did those of other groups. A significant but very slight depression of weight gain was seen in females of the 300 ppm group for a week after commencement, followed by a rapid recovery to the control level.
In rats of the 30000 ppm group a depressed weight gain and dwarfism similar to that observed in mice was seen in males. Weight gain of females in this group was slightly depressed during the study with significant differences to control animals in the 1st to 5th weeks of the study.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

The food intake of male and female mice in the 30000 ppm group was depressed during the first week of the study in comparison to that of the controls but showed a tendency to recover afterwards. Average intake of these animals then remained at only a slightly lower level than that of the control group. In rats, the food intake of males decreased after the third week of the study in the 30000 ppm group. A similar reduction was seen in females of this group during the 1st to 6th weeks but then disappeared. A slightly lower value of average food intake was disclosed in only males.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Food efficiencies of of male and female mice in the 30000 ppm group were markedly lower than those of the control group during the first week of the study, corresponding to the decrease in food intake. The overall average food efficiency in the 30000 ppm group was much lower than the control group. While there were some fluctuations in food efficiency of rats in each group, a slight reduction in overall average value was shown only in males of the 30000 ppm group.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Male and female mice in the 30000 ppm group showed moderately lower values in hematocrit and hemoglobin concentration than those of the control group; the leukocyte count in males also decreased moderately.
In rats, a moderate reduction in leukocyte count was shown in both sexes in the 30000 ppm group; males also disclosed a slight decrease in hematocrit and hemoglobin concentration. There were no remarkable changes in animals in the less than 3000 ppm group, but there was a slight increment of hemoglobin concentration in females in the 3000 ppm group.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Mice of both sexes in the 30000 ppm group showed a slight to moderate decrease in total protein, glucose and cholesterol and a moderate to marked increase in alkaline phosphatase and urea nitrogen. Additional significant changes occurring in these animals were depression of GPT level and increase in calcium level in females, and an increase of GOT level in males.
Significant reductions or reductive tendencies were seen in rats in the following parameters: GOT and GPT in all male chemically fed groups, total protein, cholesterol and calcium levels in males in the 30000 ppm group and calcium level in females in both the 3000 and 30000 ppm groups.

Urinalysis findings:

not examined

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

Male and female rats in the 30000 ppm group showed a symptom of discarding the diet from the food jar by picking it out with their fore-limbs. This symptom began a week after commencement of the experiment and persisted throughout the study.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Organ weight analysis of the mice revealed that coincidental increase in absolute and relative weight was found in the thyroids of males and the kidneys of females in the 30,000 ppm group.
In the organ weights of the rats, a slight or moderate decrease in absolute and relative weights was seen in the liver and kidney among males in the 30000 ppm group.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

In mice, marked emaciation, ischemic discoloration of the kidney and thyroid, strophy of the pancreas, edematous thickening of the upper small intestine and slight splenomegaly were recorded in the 30000 ppm group at necropsy, in addition to several cases of forestomach ulcer.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Mice (30000 ppm): impairment of the urinary tract and regressive changes in the exocrine gland of the pancreas. Morphological changes of erythrocyte, anisocytosis, polychromatophilia and poikilocytosis, were seen in 6 males and 4 females which were reported by necropsy or microscopic observation to have fore-stomach ulcers. There were lesions attributable to the treatment in the pancreas, upper intestine, stomach, spleen and kidney from mice in the 30000 ppm group. The pancreatic acinar cells had swollen nuclei with an increased number of clarified nucleoii and whirl-like profiles in their cytoplasm which were more basophilically stained than the controls. Single cell necrosis of the acinar cells was also a common feature in these animals. Moreover, a decrease in the number of acinus and ductulelike metaplasia of acinar cells was demonstrated. There were mucosal catarrh in the upper intestine with proliferation of epithelial cells and edema at lamina propria, slight to moderate ulcerative lesions in the boundary of the fore-stomach and proliferation of erythropoietic immature cells in the splenic red pulp of these animals. Regressive changes of the renal cortex were observed in the females.
In rats, pancreatic lesions similar to those in mice were seen in the 30000 ppm group, as well as degeneration and necrosis of the acinar cells, clarification of centroacinar cells and interstitial fibrosis. No other lesions attributable to the treatment were found in rats.

Histopathological findings: neoplastic:

no effects observed

Dose descriptor:

NOEL

Remarks:

mice and rats

Effect level:

9 120 ppm

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male/female

Basis for effect level:

clinical biochemistry

gross pathology

haematology

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Dose descriptor:

NOEL

Remarks:

mice

Effect level:

1 392 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male

Basis for effect level:

clinical biochemistry

gross pathology

haematology

organ weights and organ / body weight ratios

Dose descriptor:

NOEL

Remarks:

mice

Effect level:

1 456 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

female

Basis for effect level:

clinical biochemistry

gross pathology

haematology

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Dose descriptor:

NOEL

Remarks:

rats

Effect level:

711 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

male

Basis for effect level:

clinical biochemistry

gross pathology

haematology

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Dose descriptor:

NOEL

Remarks:

rats

Effect level:

739 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

converted to target substance

Sex:

female

Basis for effect level:

clinical biochemistry

gross pathology

haematology

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Critical effects observed:

no

The target substance contains 7.5 % Zn ions. Therefore, the hazard value for Zn ion is converted to the target substance considering a Zn content of 7.5 %.

NOEL (mice & rat, m/f) (ZnSO4.7H2O) = 3000 ppm

NOEL (mice & rat, m/f) (Zn; ZnSO4.7H2O*0.228) = 684 ppm

NOEL (mice & rat, m/f) (target substance; Zn/0.075) = 9120 ppm

NOEL (mice; m) (ZnSO4.7H2O) = 458 mg/kg bw/day

NOEL (mice; m) (Zn; ZnSO4.7H2O*0.228) = 104.42 mg/kg bw/day

NOEL (mice; m) (target substance; Zn/0.075) = 1392.32 mg/kg bw/day

NOEL (mice; f) (ZnSO4.7H2O) = 479 mg/kg bw/day

NOEL (mice; f) (Zn; ZnSO4.7H2O*0.228) = 109.21 mg/kg bw/day

NOEL (mice; f) (target substance; Zn/0.075) = 1456.16 mg/kg bw/day

NOEL (rat; m) (ZnSO4.7H2O) = 234 mg/kg bw/day

NOEL (rat; m) (Zn; ZnSO4.7H2O*0.228) = 53.35 mg/kg bw/day

NOEL (rat; m) (target substance; Zn/0.075) = 711.36 mg/kg bw/day

NOEL (rat; f) (ZnSO4.7H2O) = 243 mg/kg bw/day

NOEL (rat; f) (Zn; ZnSO4.7H2O*0.228) = 55.40 mg/kg bw/day

NOEL (rat; f) (target substance; Zn/0.075) = 738.72 mg/kg bw/day

Conclusions:

Considering the Zn concentration of max. 7.5 % in the target substance, the maximum no-effect level of the target substance was determined to be 9120 ppm, which is approximately equivalent to the following milligram doses: mice: male 1392 mg/kg/day, female 1456 mg/kg/day, rats; male 711 mg/kg/day, female 739 mg/kg/day.

Executive summary:

ICR mice and Wistar rats of both sexes were fed a diet containing ZnSO4 at 0, 300, 3000 and 30000 ppm for 13 weeks. Animals in the 30000 ppm group showed retarded growth along with low food intake, abnormal values in a few hematological parameters and regressive changes of the pancreatic exocrine gland. In addition, mice had decreased water intake and significant deviations in biochemical parameters, toxic lesions appeared in the stomach, intestine and spleen of both sexes and in the kidney of females. Four males and one female mouse were found dead or moribund during the study. The maximum no-effect level of ZnSO4 was determined to be 3000 ppm, which is approximately equivalent to the following milligram doses: mice: male 458 mg/kg/day, female 479 mg/kg/day, rats: male 234 mg/kg/day, female 243 mg/kg/day.

Considering the Zn concentration of max. 7.5 % in the target substance, the maximum no-effect level of the target substance was determined to be 9120 ppm, which is approximately equivalent to the following milligram doses: mice: male 1392 mg/kg/day, female 1456 mg/kg/day, rats; male 711 mg/kg/day, female 739 mg/kg/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

10 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

EDDHA

The subchronic toxicity of Fe(Na)EDDHA (CAS 84539 -55 -9) by oral route was investigated in rats (Novartis Crop Protection AG, 1998). The test item was administered to 10 Sprague-Dawley derived rats/sex/dose level by oral gavage at 5, 50 or 200 mg/kg bw/day for 90 days. A concurrent control group was treated with the vehicle only. Additional 10 animals/sex of the high dose and control group were kept on control diet for a 4 -week recovery period before sacrifice. Treatment with the test item resulted in lower food intake and impaired body weight development at 200 mg/kg bw/day. Reversible effects on red blood cell (normochromic anaemia) and white blood cell parameters, and higher values of platelets and prothrombin activity were noted at 50 and/or 200 mg/kg bw/day. In addition, changes of blood chemistry and urine parameters concerning the liver and kidneys were noted. The body weight relative heart weight was increased in males at 200 mg/kg bw/day. Under the conditions of this study, the NOAEL for Fe(Na)EDDHA when administered daily by oral gavage for three months was 10 mg/kg bw/day (estimated from the LOAEL).

Estimation of NOAEL:

A more realistic NOAEL was estimated from the LOAEL of 50 mg/kg bw/day applying an assessment factor of 5. This method is applicable and scientifically justified for this test, as only slight adverse effects were observed at 50 mg/kg bw/day (haematology parameters - anaemia). To take the relatively large concentration gap between 5 (clear NOEL) and 50 mg/kg bw/day into account, 5 mg/kg bw/day was not taken as NOAEL, but extrapolated from the LOAEL. The guidance on information requirements and CSA, R.8 (ECHA, 2008 -2010) recommends a factor between 3 and 10 for extrapolation from LOAEL to NOAEL. An assessment factor of 5 seems to be appropriate and conservative enough for the current study as only slight effects were observed at the LOAEL of 50 mg/kg bw/day. Consequently a NOAEL of 10 mg/kg bw/day is calculated for this study.

In a dose range-finding subacute oral toxicity study (CIBA-GEIGY Limited, 1996a), Fe(Na)EDDHA was administered to 5 Sprague-Dawley derived rats/sex/dose level by oral gavage at 50, 200 or 1000 mg/kg bw/day for 28 days. A concurrent control group was treated with the vehicle only. Treatment with the test item resulted in impaired body weight development at 200 and 1000 mg/kg bw/day and correspondend lower food intake. Anaemia without erythropoietic response was noted at 200 and 1000 mg/kg bw/day. At the same dose levels, the kidney was revealed as target organ by microscopical examination, by blood chemistry data evaluation and by organ weight evaluation. In addition, body weight relative organ weight changes were noted in the heart, adrenals and spleen. However, the relevance of these findings was considered as equivocal. This study was used as scientific basis for dose level selection for the above-mentioned 90 -day repeated dose oral toxicity study in the rat.

13 weeks feeding study (Maita 1981)

ICR mice and Wistar rats of both sexes were fed a diet containing ZnSO₄ at 0, 300, 3000 and 30000 ppm for 13 weeks. Animals in the 30000 ppm group showed retarded growth along with low food intake, abnormal values in a few hematological parameters and regressive changes of the pancreatic exocrine gland. In addition, mice had decreased water intake and significant deviations in biochemical parameters, toxic lesions appeared in the stomach, intestine and spleen of both sexes and in the kidney of females. Four males and one female mouse were found dead or moribund during the study. The maximum no-effect level of ZnSO4 was determined to be 3000 ppm, which is approximately equivalent to the following milligram doses: mice: male 458 mg/kg/day, female 479 mg/kg/day, rats: male 234 mg/kg/day, female 243 mg/kg/day.

Considering the Zn concentration of max. 7.5 % in the target substance, the maximum no-effect level of the target substance was determined to be 9120 ppm, which is approximately equivalent to the following milligram doses: mice: male 1392 mg/kg/day, female 1456 mg/kg/day, rats; male 711 mg/kg/day, female 739 mg/kg/day.

Justification for classification or non-classification

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