Tin disulphide

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was conducted with a similar substance according to standard methods and GLP, therefore it is considered reliable and relevant, but in isolation, not adequate for classification. However, as various anchor points demonstrated a similar structural and physicochemical characteristics and comparable toxicological profile ( various acute toxicity, genotoxicity and local tolerance endpoints), these read-across results are also considered adequate for classification regarding repeated dose toxicity of Tin disulfide.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tin sulfide CAS 1314-95-0

IUPAC Name:

Tin sulfide CAS 1314-95-0

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Bio Test s.r.o., Czech Republic
- Age at study initiation: 7-8 weeks at treatment start; 6-7 weeks on delivery
- Weight at study initiation: Main Study: Males 166-188g; Females 126-140g
- Fasting period before study: Not provided
- Housing: 2-3 animals of the same sex/cage in Macrolon 2000P cages (Tecniplast), Tier Wohl Classic (JRS, Germany) was used as bedding
- Diet (e.g. ad libitum): Standard pelletized diet NOE H4 (Racio Breclav, CZ), ad libitum, feed containers were changed and sanitized at least once weekly.
- Water (e.g. ad libitum): Water of monitored quality, ad libitum; water containers were changed and sanitized at least once weekly.
- Acclimation period: 5 days (DRF); 6 days (Main study)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24°C
- Humidity (%): 30-70%
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5% methylcellulose

Details on oral exposure:

Four groups of rats were daily administered with the test item suspension in 0.5% CMC orally by gavage for 90 days.

PREPARATION OF DOSING SOLUTIONS: For the preparation of a homogenous suspension the following procedure was adopted: at first the weighted amount of the respective substance was ground in a grinding mortar with a small volume of carrier liquid. Then the content of the mortar is transferred into a calibrated vessel. Another amount of carrier liquid is poured into the mortar, stirred and the mortar with the pestle is rinsed, the rinsing liquid being added into the same calibrated vessel. This rising is repeated once more. Then the volume in the calibrated vessel is made up with the carrier liquid to the required volume and mixed on magnetic stirrer using 1000 rpm for 10 minutes. Immediately before the application, the suspension is again stirred by means of an electromagnetic stirrer.
Each rat in a dose group received the appropriate dose of the Test item as methylcellulose suspension in volume of 1 mL per 100g of body weight per day, by gavage for 14 (DRF) or 90 (90-Day Subchronic Toxicity Study) consecutive days. Control animals were administered by vehicle in the same volume and the same way.
Individual doses were adjusted according to the weekly body weight.
The first day of dosing was designated as Day 1 of each part of the study.


VEHICLE
methylcellulose is used as vehicle in this study in a concentration of 0.5%
- Lot/batch no. (if required): 3.12.2010

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

See full study report

Duration of treatment / exposure:

90 days

Frequency of treatment:

Daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

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

Remarks:

orally by gavage

Doses / concentrations 2

Dose / conc.:

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

Remarks:

orally by gavage

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Remarks:

orally by gavage

No. of animals per sex per dose:

4 (DRF)
10 (Main Study)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The oral route of administration is described by the guideline OECD 408. Doses for the DRF study were proposed by the Sponsor and were based on following study results.
Insoluble tin compounds were demonstrated to have minimal toxic effects in rats when administered for 28 days in the diet. Feeding rats on diets containing 0.0, 0.03, 0.10, 0.30 or 1.00% of Tin sulfide did not result in adverse effects on mortality, body weight change, diet utilization, measurements of blood, urine and biochemical parameters, organ weights and gross and micropathology. The amount of 1% in the diet was calculated to correspond with approximately 670 mg/kg body weight/day on average basis. Therefore, the maximum dose to be tested was proposed to be 1000 mg/kg body weight/day in the dose range finding experiment.
References:
- WHO Food Additives Series Vol:46 (2001) pp 307-60;
- de Groot A. P., Feron V. J., Til H. P. Short-term toxicity studies on some salts and oxides of tin in rats. Food and Cosmetics Toxicology, Volume 11, Issue 1, February 1973, ppPages 19-30.
Based on above mentioned data doses for the DRF study were 500 and 1000mg/kg. Dose levels for 90-Day Toxicity Study were established based on the results of the DRF study in which doses of 500 and 1000 mg/kg administered daily for 14 day were without any signs of toxicity.
- Rationale for animal assignment (if not random): Animals were sorted according to the body weight, and allocated to the dose group taking animals from each range group according to SOP SN-TOX-00.

Positive control:

No

Examinations

Observations and examinations performed and frequency:

All animals were checked daily for clinical signs. Individual body weight and food consumption were recorded weekly.Before the first administration (day -1) and at the end of the study (day 90) blood and urine samples were taken from all animals for hematology, clinical chemistry and urinalysis examinations. Ophthalmoscopy was also performed initially and termininally on all animals. At the end of the study (day 90), gross necropsy of all rats was performed and organ and tissue samples according to study plan were taken for histopathological examinations.

CAGE SIDE OBSERVATIONS: Yes
All rats were observed for clinical signs, morbidity or mortality.
Onset, duration and severity of any signs were recorded. Dead animals were removed, sacrificed and examined histopathologically.
- Time schedule: daily in the acclimation and administration period in the DRF Study and twice a day during the acclimation and administration period in the 90-Day Subchronic Toxicity Study.

DETAILED CLINICAL OBSERVATIONS: Yes
Signs noted include, but were not limited to: changes in skin, fur, eyes, mucous membranes, occurrence of secretions and excretions, autonomic activity (e.g. lacrimation, piloerection, pupil size, and unusual respiratory pattern). Changes in gait, posture, response to handling, presence of clonic or tonic movements, stereotypes (e.g. excessive grooming, repetitive circling) or bizarre behavior (e.g. self mutation, walking backwards) were recorded. Observed changes were recorded using scoring system (SOP: SN-TOX-00, STU-12-00).
- Time schedule: before the first exposure and then once a week.

BODY WEIGHT: Yes
- Time schedule for examinations: at delivery, before the first administration, then weekly during the administration period and before the necropsy.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
Individual food consumption was recorded weekly during the study period


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: Both eyes of each animal were examined by direct and indirect ophthalmoscopy (Ophthalmoscope KEELER Professional, UK) during pre-treatment, and at the end of the administration period (Day-2, Day 86).
- Dose groups that were examined: each animal

HAEMATOLOGY: Yes
- Time schedule for collection of blood: before administration and at the end of administration period.
- Anaesthetic used for blood collection: Yes , slight ether anesthesia from the retro-orbital venous plexus into tubes Vacuette, Greiner bio-one, containing K3EDTA (hematology), sodium citrate (for coagulation) and into TAPVAL (without anti-coagulant for serum clinical chemistry).
- Animals fasted: Yes , approx. 12-18 hours before blood sampling, but water was provided ad libitum
- How many animals: all animals
- Parameters checked in table No.7-15(DRF) ; 49-64 (Main Study) were examined.
Erythrocyte count, Hemoglobin, Hematocrit, Mean corpuscular volume, Mean corpuscular hemoglobin, Mean corpuscular hemoglobin concentration, Leukocyte count, Platelet count, Nucleated RBC, Differential leukocyte count, Activated partial thromboplastin time, Prothrombine time, Differential count of bone marrow cells(M/E ratio).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: before administration and at the end of administration period.
- Animals fasted: Yes , approx. 12-18 hours before blood sampling, but water was provided ad libitum
- How many animals: all animals
- Parameters checked in table No.16-21 (DRF); 65-74 (Main Study) were examined.
Glucose, Sodium, Potassium, Phosphorus, Chloride, Calcium, Urea, Creatinine, Alkaline phosphatase, Alanine amino transferase, Aspartate amino transferase, Lactate Dehydrogenase, Gamma-Glutamyl Transpeptidase, Triglycerides, Bilirubin total, Cholesterol, Protein total, Albumin, Globulin, Albumin/Globulin ratio.

URINALYSIS: Yes . Macroscopic analysis and semi-quantitative biochemical analysis (Automatic Analyzer Aution MINI, ARKRAY, Japan) were performed.
- Time schedule for collection of urine: before administration and at the end of administration period.
- Metabolism cages used for collection of urine: Yes , after previous oral administration of distilled water.
- Animals fasted: No data
- Parameters checked in table No.22-24 (DRF); 75-78 (Main Study) were examined.
Appearance/ color, Specific gravity, pH, Protein, Bilirubin, Urobilinogeen, Blood, Ketones, Nitrite, Leucocytes, Glucose

Sacrifice and pathology:

At the end of the study (day 90), gross necropsy of all rats was performed and organ and tissue samples according to study plan were taken for histopathological examinations.
GROSS PATHOLOGY: Yes (Tables 79-86; 95)
HISTOPATHOLOGY: Yes (Tables 87-94; 96)

Other examinations:

Organ weights; Organ weights and terminal body weights were used for the calculation of organ-to-body weight ratios. (Tables 97-112 (individual values Main Study); Tables 113-116 (statistics Main Study))

Statistics:

DRF Study
Data of body weight, food consumption, hematology including bone marrow smears and clinical chemistry as well as gross pathology were not statistically processed in the DRF study. Group mean values and SD values were counted only.
90-Day Subchronic Toxicity Study
Group mean and standard deviations were calculated for body weights, food consumption, clinical pathology (except for urinalysis) values and organ weights (absolute and relative weights). Absolute and relative organ weights for test article treated groups were compared to those of controls (D1, D2 and D3 versus C) using the Student’s t-Test. In addition, body weights, food consumption and clinical pathology values were subjected to analysis of variance (ANOVA) followed by Dunnett’s Test, if applicable; additional statistical analyses (Kruskall-Walis) were performed as required by the data. Statistical evaluation was performed using Graph Pad Prism software, version 4, validated on September 22, 2009.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Details on results:

Results: Tin sulfide orally administerd in rats for 90 consecutive days caused a slight increase in food consumption, associated with slight increases in body weight and serum glucose concentrations in females dosed at 1000 mg/kg. These were however not considered as adverse affects. Slight dose dependent decreases in serum Na and Cl, varying within physiological range, were observed. Except for the above mentioned changes, Tin sulfide did not cause any negative effect on body weight, food consumption, ophthalmoscopy, hematology and clinical chemistry parameters and organ weights. Tin sulfide further did not cause any organ weight changes nor gross or histopathological changes in the liver, kidneys, gastrointestinal tract or other organs of survived animals indicate of a toxic effect. Under the test conditions used, 90 - day administration of the test item Tin sulfide to rats was safe and well tolerated up to the dose of 1000 mg/kg bw/day. The NOAEL was defined at 1000 mg/kg and the NOEL at 300 mg/kg

Main study
CLINICAL SIGNS AND MORTALITY
All rats were daily observed for clinical signs, morbidity or mortality during the acclimation and administration period. Onset, duration and severity of any signs were recorded.
Three rats from different groups did not survive till their scheduled necropsy. Rat F108 (group D3) died on February 28, 2010 (day 53), rat M76 (group D2) died on March 19, 2010 (day 71) and rat F48 (group C) died on April 2, 2010 (day 87). Cause of the death most probably was incorrect Test item administration leading to oesophagus perforation. Death of all three rats was not related to the treatment. Detailed description of the findings is presented in section 4.2.2.
In several cases slight reversible loss of fur was observed. This loss of fur was probably not treatment related.
No signs of toxicity were recorded in all other administered animals of all tested groups during observation period.

BODY WEIGHT AND WEIGHT GAIN
The body weights of all animals of control and dosed groups increased during the study. When compared to the control group, we observed a slight decrease in mean body weight of males of the D3 group in the first week and a slight increase in mean body weight of the males of the D1 and D2 groups in the third week of the administration period . In females we observed a slight decrease in body weight of the D2 group in the first week of the study versus the control group. There was a statistically significant increase (9-10%) in body weight of females of group D3 versus the control group, starting from week 9 onwards and persisting till the end of the study. In the last week of the study, a slight decrease in mean body weight versus the previous week was observed in all groups of both sexes, most probably caused by more frequent handling of the animals for blood sampling and starvation before sampling and necropsy.
No adverse effects of the Test item administration on body weight of animals of both sexes was proven. Increased body weight of females administered with the highest dose was most probably treatment related, but not considered as adverse effect.

FOOD CONSUMPTION AND COMPOUND INTAKE
A high variability in food consumption was observed in males and females of all dosed and control groups in the course of the study. The males of almost all dosed groups consumed more food in the first three weeks of the study when compared to the control group. At the end of the study, male rats from the D2 and D3 groups consumed statistically significant more food than the control animals. In only one case, we observed a decrease in food consumption of male rats in group D1 in the eleventh week of the study. Female rats consumed comparable or higher amount of food when compared to control animals in the course of the study, except in two cases – D2 in the fifth week and D1 in the seventh week of administration period. In the last week of the study we recorded a decrease in food consumption of both sexes in all groups, correlating with decreased body weight, most probably caused probably by more frequent handling of the animals due to blood sampling.
Tin sulfide at all doses increased food consumption of both sexes, however most pronounced in the highest dosed females, where it was associated with slightly increased body weight. No adverse effect, however, of the Test item administration on food consumption of animals of both sexes was concluded.

OPHTHALMOSCOPIC EXAMINATION
None of the animals showed any pathological changes on the eyes in the course of the study.

HAEMATOLOGY
Red Blood Cells Count (RBC, HGB, HCT, MCV, MCH, MCHC)
Increases in mean RBC, HGB and HCT values compared to the first examination was noted on Day 90 in all monitored groups, except for the D2 females. The mean RBC values even varied slightly above the reference limit1 in C and D1 males and C females. These variations were most probably the reason for statistically significant differences found in mean RBC and HCT values in D1 females (on Day -1) and mean RBC, HGB and HCT values in D1 and D2 females(on Day 90).
The decrease in mean MCV and MCH values was observed in all the groups (slightly below the reference ranges1) as compared to the first examination. Statistically significant differences found in the other red blood parameters were neither dose nor treatment related.

White Blood Cells Count and Differential Leukocytes Count (WBC, SN, BN, EO, BA, LY, MO)
No significant changes were observed in mean WBC values during the study period. All mean WBC values varied within the reference limits 1 and statistically significant differences were found in D1 females (on the Day -1) and D1 and D2 males (on the Day 90) when compared to control group were treatment unrelated. Most of the differential leukocytes parameters varied within the reference limits 1 during the study period, except for the sporadically higher SN and MO counts, which were found only before the administration period. Sporadic statistically significant changes observed were treatment unrelated and biologically insignificant.

Hemostasis and coagulation (PLT, PT, APTT)
No considerable changes were found in mean PLT, PT and APTT values during the study period in all the dose groups as compared to the starting levels. Statistically significantly lower mean PLT values noted in females in group D1 and D2 (Day 90) as compared to the control group were biologically insignificant. All mean PLT values varied within the reference limits1.

Differential bone marrow Count
Physiological cellularity was observed in all the examined smears. All evolutional stages were found in white blood cell granular series and maturation of cells was clearly visible in all the monitored groups. The erythrocyte series included all important stages from proerythroblast to normoblast. Lymphocyte series were represented mainly by matured cells in standard quantity. Statistically significant decrease in prolymphocyte values in D2 animals and D3 females (comparing to control group) were treatment independent.

CLINICAL CHEMISTRY
Increases in mean glucose (Glu) values in D1 males, D2 and especially in D3 animals were observed during the study period. However, all mean glucose levels varied within the reference limits 2. No increase of glucose was found in the control group during the study period. The changes observed in D2 males and D3 females at the end of the administration period were statistically significant as compared to control group. Taking into account the increase of body weight and food consumption in female rats od D3 group, relation of these findings to the treatment is probable, but not considered as adverse effect.
Mean values of serum concentrations such as sodium (Na) and chloride (Cl) slightly decreased during the study period in dosed groups as compared to starting levels. These findings were not observed in the control group. The slight decrease in mean potassium (K) was observed mainly in females. The decrease in mean calcium (Ca) was noted in dosed groups too, except for the high dose group (D3). The decrease of mean phosphorus (P) value recorded at the end of the administration period corresponding to the age of animals was more noticable in dosed groups as compared to control groups (statistically significant differences in females of all the dosed groups and D1 and D2 males). All the other values varied within the reference limits 2. The changes in mineral elements especially in mean Cl and Na concentrations could be dose-dependent.
No considerable changes were recorded in serum urea (Urea) and creatinine (Crea) concentrations in all the monitored groups. All the values varied within the reference limits 2. Statistically significant differences observed before the Test item administration period as compared to control group were treatment unrelated.
No considerable variations were recorded in total bilirubin (Bil) mean values during the study period.
No statistically significant changes in mean serum activities of Lactate dehydrogenase (LDH), Aspartate aminotransferase (AST), Gamma-glutamyl transpeptidase (GGT) and Alkaline phosphatase (ALP) were noted in treated animals as compared to controls at the end of the study. The decrease in mean ALP serum activity in all the monitored groups including control corresponded to the age of animals. Slight increases in mean Alanine aminotransferase (ALT) serum activities were noted in dosed groups but all the mean values varied within the reference limits 2.
Statistically significant differences as compared to control group were found in D2 females. These findings can be considered as treatment independent.
No significant variations of mean cholesterol (Chol) and triglycerides (TAG) values were found.
A statistically lower mean cholesterol value found in D1 males at the end of the administration period was biologically insignificant as well as the statistically significant differences observed in mean cholesterol and TG values before the Test item administration.
No considerable changes were noted in mean total protein (TP), albumine (Alb), globuline (Glo) and ratio Alb/Glo serum values in all the monitored groups.

URINALYSIS
All urine samples were of yellow colour and clear without any signs of turbidity.
Slightly higher individual glucose values were noted before the Test item administration in dosed groups as compared to reference values 3. However, at the end of the Test item administration period (Day 90) all individual glucose levels were within the normal range 3.
Similarly, slightly higher individual protein values were observed in control and dosed animals (males and females) during the first examination. In Examination 2 (Day 90) all these values varied within the reference ranges3.
No treatment related changes were found in bilirubin and urobilinogen values in dose groups as compared to control group.
No considerable differences in pH, specific gravity and nitrites were found between control and dosed groups. Sporadic slightly higher individual ketone values were noted only in the first examination in all the groups including control group.
Sporadic occurrence of blood in urine, predominantly in dosed groups, was detected mainly in the first examination (before the Test item administration period). Presence of leukocytes varied within normal ranges 3 in all the animals during the study period.
The urine volume measured in dose groups was comparable to that in control group.

ORGAN WEIGHTS
No statistically significant differences of mean absolute or relative organ weight were recorded in any of the tested groups in comparison to the controls.

GROSS PATHOLOGY
Prematurely died animals
Three rats prematurely died during the course of the study.
Female F108 (D3) prematurely died after the 52nd drug administration. Traumatic perforation of the esophagus caused by gavage during the oral drug administration was demonstrated at necropsy. This incorrect administration led to development of a paraesophageal abcess and fibrinopurulent inflammation in mediastinum including thymus tissue. Severe venostasis in the lungs, liver, and kidneys of this animal indicated a circulatory failure as the most probable cause of death. Death of this animal was not in direct relation to the Test item administration.
Male M76 (D2) died after hhe 71st drug administration. The cause of its death was considered to be respiratory insufficiency due to incorrect administration of the Test item into lungs. Death of this animal was not in direct relation to the Test item toxicity.
Control female F48 suddenly died 1 hour after the 87th drug administration. Histopathology examination revealed severe atelectasis in the lungs caused most probably by pressure-tight handling during the Test item administration and marked venostasis in parenchymatous organs indicating a circulatory failure as the cause of death. Death of this female was not in relation to the Test item administered.
No Gross pathological changes related to the treatment were found in animals survived till the end of the study.

HISTOPATHOLOGY: NON-NEOPLASTIC
Liver
Focal area(s) of mononuclear cell infiltration in the parenchyma of the liver was noticed in some control and treated animals. This finding appears as one of the most frequent spontaneous microscopic lesions in rat liver (Greaves, 2000).
Remaining findings (venostasis) concerning prematurely died animals is discussed above.
Staining of liver sections with Oil red O for presence of lipid substances did not reveal substantial differences between control and the highest dose group animals.

Kidneys
Findings in the kidneys concerned both control and administered rats (cortical scar, hyaline cast, hydronephrosis, corticomedullary mineralization, tubular basophilia) and were without relation to the treatment.
Venostasis found in prematurely died animals is discussed above.

Lungs
Gross pathology examination revealed multiple grey-green foci in the lungs of four administered rats (M60-D1, M71-D2, F104-D3, F107-D3). Microscopic examination demonstrated the presence of multiple black pigment particles of different size with eosinophilic homogenous masses in lung alveoli. Further frequent foamy macrophages and sporadic giant cells reaction around pigment particles was seen as a manifestation of resorptive reaction. Mentioned black pigment was also found in the mediastinal lymph node of one female (F107-D3). Described black pigment was aspirated Test item.
Small foci of lipidosis characterized by accumulation of foamy macrophages were found in some control and treated animals. Other lesions were solitary (blood aspiration, focal hemorrhage, venostasis) without direct relation to the Tin sulfide administered or they were found in died animals (atelectasis, presence of black pigment in alveoli and bronchi, emphysema, oedema) and are discussed above.

Gastrointestinal tract
There were found no treatment related changes in gastrointestinal tract.

Hematopoietic and lymphatic systems
Focal hemorrhage was the most frequent finding in the lymph nodes of some control and administered animals, bearing no relation to the Tin sulfide tested similarly like presence of hemosiderin in the cervical lymph node of one treated rat.
Thymus tissues of all animals survived to their scheduled necropsy were without any pathological changes except for marked thymus atrophy found in one treated animal (F87-D2) and focal hemorrhage and cyst revealed in some control and treated animals. All lesions were without relation to the tested substance. Venostasis found in thymus of the male M76 (D2) that died was most probably an agonal lesion and the fibrinopurulent inflammation observed in female F108 (D3) is discussed above.
No pathological changes were observed in the spleen of tested animals.

Miscellaneous findings
All pathological changes described in the eye and lacrimal gland were secondary lesions in consequence of previous blood sampling for clinical pathology examination from retroorbital venous plexus so they could not be attributed to the substance tested.
Focal alopecia of small extent was observed during necropsy on the skin of 7 treated animals. Focal hair loss was histologically found in 3 cases, no inflammatory infiltrate was observed in the dermis. As hair loss can result from animal grooming activity (Greaves, 2000) and the fact that it is reversible, we suppose it has a spontaneous origin.

Other histological findings were observed either in control animals only, or in control and administered animals together, or they were of a subsidiary nature, with no relation to the substance tested.

Effect levels

1

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Under the test conditions used, 90 - day administration of the test item Tin sulfide to rats was safe and well tolerated up to the dose of 1000 mg/kg bw/day. The NOAEL was defined at 1000 mg/kg and the NOEL at 300 mg/kg.

2

Dose descriptor:

NOEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Under the test conditions used, 90 - day administration of the test item tin sulfide to rats was safe and well tolerated up to the dose of 1000 mg/kg bw/day. The NOAEL was defined at 1000mg/kg and the NOEL at 300 mg/kg.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Tin sulfide orally administered in rats for 90 consecutive days caused a slight increase in food consumption, associated with slight increases in body weight and serum glucose concentrations in females dosed at 1000 mg/kg. These were however not considered as adverse affects. Slight dose dependent decreases in serum Na and Cl, varying within physiological range, were observed. Except for the above mentioned changes, Tin sulfide did not cause any negative effect on body weight, food consumption, ophthalmoscopy, hematology and clinical chemistry parameters and organ weights. Tin sulfide further did not cause any organ weight changes nor gross or histopathological changes in the liver, kidneys, gastrointestinal tract or other organs of survived animals indicate of a toxic effect. Under the test conditions used, 90 - day administration of the test item Tin sulfide to rats was safe and well tolerated up to the dose of 1000 mg/kg bw/day. The NOAEL was defined at 1000 mg/kg and the NOEL at 300 mg/kg.

Applicant's summary and conclusion

Conclusions:

Tin sulfide showed no effects considered as adverse in a subchronic toxicity study according to OECD guideline 408. The NOAEL was defined at 1000 mg/kg and the NOEL at 300 mg/kg.

Executive summary:

The 90- day study provides information on the possible health hazards likely to arise from repeated exposure over a prolonged period of time covering post-weaning maturation and growth well into adulthood. The study will provide information on the major toxic effects, indicate target organs and the possibility of accumulation, and can provide an estimate of a no-observed-adverse-effect level of exposure which can be used in selecting dose levels for chronic studies and for establishing safety criteria for human exposure.The test substance is orally administered daily in graduated doses to several groups of experimental animals, one dose level per group for a period of 90 days. During the period of administration the animals are observed closely for signs of toxicity. Animals which die or are killed during the test are necropsied and, at the conclusion of the test, surviving animals are also killed and necropsied.

Four groups of rats (male/female wistar rats) were daily administered with the test item suspension in 0.5% Carboxymethylcellulose (CMC) orally by gavage for 90 days.Three treated groups were administered with doses of 100, 300 and 1000 mg/kg bw per day. Control group was administered by the vehicle (0.5%) CMC, only. All animals were checked daily for clinical signs. Individual body weight and food consumption were recorded weekly.Before the first administration (day -1) and at the end of the study (day 90) blood and urine samples were taken from all animals for hematology, clinical chemistry and urinalysis examinations. Ophthalmoscopy was also performed initially and termininally on all animals. At the end of the study (day 90), gross necropsy of all rats was performed and organ and tissue samples according to study plan were taken for histopathological examinations.

Tin sulfide orally administered in rats for 90 consecutive days caused a slight increase in food consumption, associated with slight increases in body weight and serum glucose concentrations in females dosed at 1000 mg/kg. These were however not considered as adverse affects. Slight dose dependent decreases in serum Na and Cl, varying within physiological range, were observed. Except for the above mentioned changes, Tin sulfide did not cause any negative effect on body weight, food consumption, ophthalmoscopy, hematology and clinical chemistry parameters and organ weights. Tin sulfide further did not cause any organ weight changes nor gross or histopathological changes in the liver, kidneys, gastrointestinal tract or other organs of survived animals indicative of a toxic effect. Under the test conditions used, 90 - day administration of the test item Tin sulfide to rats was safe and well tolerated up to the dose of 1000 mg/kg bw/day. The NOAEL was defined at 1000 mg/kg and the NOEL at 300 mg/kg.