Polysulfides, bis[3-(triethoxysilyl)propyl]

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

The key reproductive study with bis[3-(triethoxysilyl)polysulfides (CAS No. 211519-85-6, EC No. 915-673-4) was conducted according to OECD Test Guideline 443 (extended one-generation reproductive toxicity study (EOGRTS)) and in compliance with GLP (Charles River Laboratories, 2022). In this study, four groups of Wistar Han rats were investigated: F0 (parental), F1 pups, F1 Cohort 1A, and F1 Cohort 1B, with the latter added primarily to assess endocrine and reproductive tissues via necropsy and organ weight measurement. Based on the findings, the overall study NOAELs were identified as follows:

- Systemic, males: 300 mg/kg bw/day, based on test item-related and adverse kidney histopathology in F0 males at 1000 mg/kg bw/day

- Systemic, females: 100 mg/kg bw/day, based on test item-related and adverse kidney histopathology in F0 females from 300 mg/kg bw/day

- Reproduction: at least 1000 mg/kg bw/day, based on the lack of test item-related reproductive effects in the F0, F1 Cohort 1A, and F1 Cohort 1B animals, and lack of reproductive / developmental effects in the F1 pups

Link to relevant study records

Reference

Endpoint:

extended one-generation reproductive toxicity - basic test design (Cohorts 1A, and 1B without extension)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2 Dec 2020 (study initiation) to 9 Jul 2021 (in-life completion)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 443 (Extended One-Generation Reproductive Toxicity Study)

GLP compliance:

yes

Limit test:

no

Justification for study design:

- Premating exposure duration for parental (F0) animals: 10 weeks per OECD Test Guideline 443
- Basis for dose level selection: Based on a previous OECD Test Guideline 414 dose range finder in which the maternal and foetal NOAELs were at least 1000 mg/kg bw/day
- Inclusion of F1 Cohort 1B: Primarily to primary assess endocrine and reproductive tissues at necropsy, with tissues process through paraffin blocks for possible histopathology depending on the F1 Cohort 1A findings
- Neurotoxicity F1 Cohorts 1A and 1B (treated PNDs 21-90 or 97) Changes in gait and posture, presence of clonic or tonic movements, stereotypy or bizarre behaviour were assessed as part of the detailed clinical observations
- Immunotoxicity F1 Cohort 1A (treated PNDs 21-90): Spleen immunophenotyping was performed at necropsy
- Route of administration: Oral gavage selected since expected route of human exposure
- Species / strain: Han Wistar rat chosen since this strain is an accepted rodent species for non-clinical toxicity testing by regulatory agencies
- Vehicle: Justification not specifically specified, but the test item was shown to be stable and homogeneous in olive oil at 21 °C
- Number of animals: At (F1 cohorts, 20/sex/dose) or slightly higher than (F0 parents, 25/sex/dose) than specified in OECD Test Guideline 443

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK, Margate, Kent, UK
- Females: F0 sexually mature, F1 Cohort 1A and 1B aged PND 21 (assessed for sexual maturation)
- Age at study initiation (dosing): F0 males: 8-9 weeks, F0 females: 7-8 weeks; F1 Cohorts 1A and 1B: PND 21
- Weight at study initiation (dosing): F0 males: 228-342 g, F0 females: 142-204 g; F1 Cohort 1A males: 39-66 g, F1 Cohort 1A females: 33-68 g; F1 Cohort 1B males: 37-69 g, F1 Cohort 1B females: 32-63 g
- Fasting period before study: No
- Housing: For all animals, appropriately sized polycarbonate cages with solid bottoms, appropriate bedding provided
> F0, Cohort 1A, 1B animals: Up to 3/sex/dose together
> F0 males few days prior to mating: Transferred to individual solid bottomed cages
> F0 females for mating: Transferred to male individual cages
> F0 males after mating: Re-housed with their original cages mates until termination from Study Day (SD) 114.
> F0 females after either positive mating sign or at end mating period: Transferred to individual solid bottomed cages and retained in this type of cage until termination LDs 22-24. Appropriate nesting material provided
> F1 pups: Housed with their dams until litter culling on PND 4 (culled pups terminated), with F1 pups selected for F1 Cohorts 1A and 1B on PND 21 housed
- Diet, F0, F1 Cohorts 1A and 1B: Special Diet Services VRF-1, ad libitum except during designated procedures
- Water F0, F1 Cohorts 1A and 1B: Public supply tap water, ad libitum via water bottles except during designated procedures
- F1 pups: Nursing PNDs 0-21
- Acclimation period: Two weeks prior to start of dosing

ENVIRONMENTAL CONDITiONS
- Temperature (°C): 17-36
- Humidity (%): 30-129, excursions outside 30-70 transient, did not affect integrity or outcome of study
- Air changes (per hr): Ten (10) or more
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1 Dec 2020 To: 9 Jul 2021

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Dose formulations were prepared at least weekly, with the aliquots removed from the freezer and allowed to warm to room temperature and stirred for at least 30 minutes before dosing. The doses were given via syringe with an attached gavage cannula. If a female was found to be in the process of littering or had recently littered at the time of scheduled dose administration, the animal was not dosed on that day.

VEHICLE
- Justification for use and choice of vehicle: Stability and homogeneity testing - Dose selection rationale: Based on OECD Test Guideline 414 dose range finder, with a maternal and foetal NOAELs of at least 1000 mg/kg bw/day (See “Justification for study design” above)
- Rationale for animal assignment: Random
- Fasting period before blood sampling for clinical biochemistry: No
- Dosing concentrations: 0, 25, 75, 250 mg/mL
- Amount of vehicle: Amount needed to derive dosing concentrations, dosing volume of 4 mL/kg for all F0 and F1 cohort groups.

Details on mating procedure:

F0 pairing was on a 1 male to 1 female basis. During the evening (after 5 pm) of Day 71 of dosing, females were housed with their allocated co-group male partner for up to 14 days. The day of detection of a copulatory plug in situ and/or of sperm in the lavage was designated Gestation Day 0. If evidence of mating was not observed by the end of the 14-day pairing period, the female was separated from the male the morning following the last night of pairing and treated as if mating had occurred during that night. F1 Cohort 1A and 1B animals were not mated.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

For each dose/stratum as relevant, five formulation samples were collected for all groups on Day 1, Week 12 and Week 25, with two samples analysed via ultra-performance liquid chromatography (UPLC) using a validated analytical procedure. The control samples were obtained from the middle stratum, while those for the treated groups were take from the top, middle, and bottom strata.

Duration of treatment / exposure:

- F0, males: 10 weeks prior to mating and continuing throughout and after mating until the day before termination from SD 114
- F0, females: 10 weeks prior to mating and continuing throughout mating and gestation until at least Lactation Day (LD) 21
- F1 pups (PNDs 0-21) were potentially exposed in utero or during lactation
- F1 Cohort 1A: From PND 21 until the day before necropsy (at least PND 90)
- F1 Cohort 1B: From PND 21 until the day before necropsy (at least PND 97)

Frequency of treatment:

Once daily

Details on study schedule:

F1 litter standardisation, PND 4:
- Litter size was standardised to 8 pups per litter (and if possible, comprised of 4 males and 4 females). Any additional pups were selected at random for use in blood sample or necropsy procedures. Culled pups were terminated on PND 4, after (as relevant) any clinical chemistry.

Cohort 1A and 1B selection, F1 PND 21:
- Among the non-culled F1 pups, 40 males and 40 females were selected at random on PND 21 and identified on that day for post-weaning treatment and assessments (F1 Cohorts 1A and 1B), nominally up to 4 males and 4 females from each litter.
- Selected pups were removed from their mother on PND 21 and housed in their new cages
- Unselected pups remained with their dam until maternal (and pup) termination on LDs 22-24.

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

300 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

- F0: 25/sex/dose
- F1 pups after PND 4 cull, 8 pups//litter, with ideally comprised of 4/sex//litter
- Cohort 1A: 20/sex/dose
- Cohort 1B: 20/sex/dose

Control animals:

yes

Details on study design:

- Dose selection rationale: Based on OECD Test Guideline 414 dose range finder, with a maternal and foetal NOAELs of at least 1000 mg/kg bw/day (See “Justification for study design” above)
- Rationale for animal assignment: Random
- Fasting period before blood sampling for clinical biochemistry: No

Parental animals: Observations and examinations:

The in-life parameters evaluated included mortality, clinical observations (cageside, pre- and post-dosing, and detailed), body weights, food consumption, water consumption (visual), oestrous cycles, data to determine reproductive (mating, fertility, and pregnancy) indices, gestation length, and deficiencies in maternal care, and clinical pathology (haematology, clinical chemistry, coagulation, T4 and thyroid stimulating hormone TSH levels, and urinalysis). The urinalysis performed was during the last week of dosing, with the blood samples for the other clinical pathology obtained prior to necropsy.

For the F0 parental animals, please see Table 1 below for the general in-life assessments.

Table 2 below provides a summary of the clinical pathology sample collection for the F0 animals (as well as the F1 pups and F1 Cohort 1A animals).

Additional F0 tables below include:
- Table 3: Haematology parameters (also applicable to F1 Cohort 1A animals)
- Table 4: Clinical chemistry parameters (“ ”)
- Table 5: Urinalysis parameters (“ “).

Oestrous cyclicity (parental animals):

Per end of Table 1 below, the oestrus cycles of F0 females were evaluated.

Sperm parameters (parental animals):

SPERM ANALYSIS
At F0 necropsy, sperm were analysed for count, motility and, for the 0 and 1000 mg/kg bw/day groups, morphology.

At terminal euthanasia, the right cauda epididymis was placed in 0.3% BSA in Medium 199 and the sperm were allowed to “swim out” into the medium. An appropriate dilution of the sperm solution was prepared and examined using a Hamilton Thorne sperm motility analyser.

The cauda epididymis was minced and suspended. Dilutions of this sperm suspension were counted using a haemocytometer to obtain a total sperm count which was expressed per cauda epididymis and per gram of cauda epididymis.

From the sperm suspensions, a sperm smear was prepared and stained with eosin Y solution. At least two hundred sperm per animal were evaluated for morphological abnormalities. Morphology analysis was conducted only for the 0 and 1000 mg/kg bw/day groups.

SPERMATID ANALYSIS:
At F0 necropsy, the right testis was decapsulated and homogenised. The homogenate was sonicated to reduce tissue debris etc, if required. The number of homogenisation resistant spermatids in dilutions of this suspension were counted using a haemocytometer to obtain a total spermatid count which was expressed per testis and per gram of testis.

Litter observations:

F1 PUPS:
For the F1 pups (litters as specified), the following parameters were evaluated: numbers of live and dead pups (live birth index), sex ratio as soon as possible after birth on PND 0, daily number of live pups through PND 21 (litter size, viability index), daily presence/absence of milk in pup stomachs through PND 21 (as feasible), visible external abnormalities daily through PND 4 and then PNDs 7, 14, and 21, body weights on PNDs 1, 4, 7, 14, and 21, anogenital distance (AGD) on PND 1, male nipple retention on PND 13, and number of pups surviving to LD 21 (lactation index).

F1 COHORT 1A:
The in-life parameters evaluated included mortality, clinical observations (cageside, pre- and post-dosing, and detailed), body weights, food consumption, water consumption (visual), oestrous cycles and sexual maturation, and clinical pathology (haematology, clinical chemistry, coagulation, T4 and TSH levels, and urinalysis). The urinalysis performed was during the last week of dosing, with the blood samples for the other clinical pathology obtained the day of necropsy.

Sexual maturation:
For the F1 cohorts, females were examined daily for vaginal opening from PND 28. The day on which the vagina becames open was recorded, as was the body weight on that day.

F1 cohort males were examined daily for balano preputial separation from PND 35. The day on which separation occurred was recorded, as was the body weight on that day.

For the F1 Cohort 1A animals, please see Table 6 below for the general in-life assessments.

Please also see these tables previously referenced for the F0 animals:
- Table 2: Clinical pathology sample collection (F0 animals, F1 pups, and F1 Cohort 1A animals)
- Table 3: Haematology parameters (F0 and F1 Cohort 1A animals)
- Table 4: Clinical chemistry parameters (“ ”)
- Table 5: Urinalysis parameters (“ “).

F1 COHORT 1B:
The in-life parameters evaluated included mortality, clinical observations (cageside, pre- and post-dosing, and detailed), body weights, food consumption, water consumption (visual), and oestrous cycles and sexual maturation.

As referenced for the F1 Cohort 1A animals, please see Table 8 below for the general in-life assessments for both of these cohorts.

Postmortem examinations (parental animals):

SACRIFICE:
At terminal sacrifice, F0 animals were euthanased by exposure to carbon dioxide, followed by recording of terminal body weight, then exsanguination.

POST-MORTEM EXAMINATIONS:
At necropsy, a full list of organ / tissues was subject to organ weights, gross pathology, histology and histopathology. Sperm motility, sperm and spermatid counts, and sperm morphology were also analysed (see description under “Sperm parameters” above). Bone marrow smears were collected, fixed and stained, but not evaluated.

Please also see these tables below:
- Table 7: F0 terminal procedures
- Table 8: F0 tissues / organs subjected to necropsy procedures, histology, and histopathology

Postmortem examinations (offspring):

F1 PUPS:
The culled F1 pups on PND 4 were necropsied on the same day, while the pups not selected for the F1 cohorts on PND 21 were necropsied on PNDs 22-24. For subsets of the culled and unselected F1 pups, T4 and/or TSH levels were determined at necropsy. In addition, a subset of tissues was collected and the organs weighed for the same subset of F1 unselected pups as the T4 and TSH sample collection / analysis.

Please see these tables below.
- Table 2: Clinical pathology sample collection (F0 animals, F1 pups, and F1 Cohort 1A animals)
- Table 9: F1 pup terminal procedures
- Table 10: F1 pup tissues subjected to necropsy procedures

F1 COHORT 1A:
At necropsy, a full list of organ / tissues was subject to organ weights, gross pathology, histology and histopathology at necropsy. Sperm motility, sperm and spermatid counts, and sperm morphology were also analysed (see description under F0 “Sperm parameters” above). Ovarian follicle counts also were obtained and spleen immunophenotyping was performed:
- The examination of the ovaries included at the very least the quantification of primordial and small growing (primary) follicles and the confirmation of the presence or absence of the corpora lutea. For each ovary, 6 step serial sections at circa 5 µm were taken at intervals of 25 µm. The first section was stained with haematoxylin and eosin for routine evaluation and the remaining 5 sections stained for IHC staining using PCNA marker for enumeration of primordial and primary follicles.
- For the immunophenotyping, approximately half of the spleen was taken from 10 rats per sex per group at necropsy, collected into tubes containing RPMI-1640 medium, and placed immediately on wet ice until processed. These samples were transferred on the day of collection to the Test Facility analytical laboratory. The immune cell population counts were determined, and expressed as a percentage of total lymphocytes.

Bone marrow smears were collected, fixed and stained, but not evaluated.

Please see Table 11 (F1 Cohort 1A terminal procedures) below. The F1 Cohort 1A tissues subjected to necropsy procedures, histology, and histopathology were the same as for the F0 animals (Table 7 below).

F1 COHORT 1B:
At necropsy, a subset of organs / tissues (primarily endocrine and reproductive but also, for example, the kidney) was subject to organ weights and gross pathology, with tissues collected and processed to paraffin blocks for possible histopathologic examination. Since the in-life phase for this study ended on 21 July 2021 (at approximately the same time as ECHA issued its “Critical aspects for designing and conducting extended one-generation reproductive toxicity (EOGRT) studies under REACH”, the F1 Cohort 1B processed tissue samples were retained, but not subject to a microscopic examination (e.g., for the kidney) was not performed.

Table 12 below presents the terminal procedures for this cohort, while the subset of tissues subjected to necropsy procedures is provided as Table 13.

Statistics:

Any data collected during the F0 pre-dose period was tabulated, summarised or statistically analysed. As appropriate by study phase and endpoint, the means, standard deviations (or % coefficient of variation or standard error), ratios, percentages, numbers, and/or incidences were reported. All statistical analyses were performed within the respective study phase, unless otherwise noted. Numerical data collected on scheduled occasions were summarised and statistically analysed according to sex and occasion, or by litter, as relevant.

Constructed variables included:
- Body weight changes: Calculated between each scheduled interval
- Food consumption: Calculated between appropriate intervals
- Organ weight relative to body weight: Calculated against the terminal body weight for scheduled occasions
- Organ weight relative to brain weight: Calculated against the brain weight for scheduled occasions

All statistical tests were conducted at the 5% significance level. All pairwise comparisons (the control group versus each treated group) were performed using two-sided tests and were reported at the 1% and 5% levels, unless otherwise noted. Across the study parameters, the statistical methods using for the inter-group comparisons included: Levene’s test, one-way ANOVA F-test, Kruskal-Wallis test, Dunnett’s or Dunn’s test, and/or Fisher’s exact test.

Reproductive indices:

Female Mating Index = Number of Females with Evidence of Pairing (or No Confirmed Mating Date but Pregnant) / Number of Females Paired

Female Fertility Index = Number of Pregnant Females / Number of Females with Evidence of Pairing (or No Confirmed Pairing Date but Pregnant)

Female Pregnancy Index = Number of Pregnant Females / Number of Females Paired

Male Mating Index = Number of Males with Evidence of Pairing (or female partner confirmed pregnant) / Number of Males Paired

Male Fertility Index = Number of Males Impregnating a Female / Number of Males with Evidence of Pairing (or Female Partner Confirmed Pregnant)

Male Pregnancy Index = Number of Males Impregnating a Female / Number of Males Paired

Gestation Index (%) = Number of Animals with Live Offspring / Number of Animals Pregnant x 100, where gestation length is calculated from GD 0 to the day the first pup is observed

Post-Implantation Loss (%) = (Number of Implantations – Total Newborn Pups) / Number of Implantations x 100

Offspring viability indices:

Live Birth Index (%) = Number of Live Pups PND 0 / Number of Newborn Pups x 100

Sex Ratio (% males) = Number of Live Male Pups PND 0 / Total Number of Live Pups PND 0 x 100

Viability Index (%) = Number of Live Pups on PND 4 / Number of Live Pups on PND 0 x 100

Lactation Index = Number of Live Pups on PND 21 / Number of Live Pups on PND 4 (post-culling) x 100

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Test item related but non-adverse F0 clinical signs were observed at 300 and 1000 mg/kg bw/day, but not at 100 mg/kg bw/day.

There was an increase in the incidence of:
- Ploughing at 1000 mg/kg bw/day
- Salivation at 300 and 1000 mg/kg bw/day

Both of these signs were predominantly observed immediately post-dose, with only a few instances at the 0-1 hour post-dosing timepoint. These findings were most likely due to the taste of the formulations, and thus were considered non-adverse.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

There were no unscheduled deaths in F0 animals.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

No test item-related effects on body weight or body weight gain were observed in the F0 animals up to 1000 mg/kg bw/day. Any statistical significance seen was due to individual variation within dose groups.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

No test item-related effects on food consumption were identified in the F0 animals up to 1000 mg/kgbw/day.

Food efficiency:

not examined

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

no effects observed

Description (incidence and severity):

Water consumption by F0 animals was monitored by visual inspection of the water bottles. No inter-group differences were noted.

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Description (incidence and severity):

There were no effects on haematology parameters in the F0 animals up to 1000 mg/kg bw/day. All values were within normal biological variation when compared with the control group.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

There were no effects on clinical chemistry parameters in the F0 animals up to 1000 mg/kg bw/day. All values were within normal biological variation when compared with the control group.

Endocrine findings:

no effects observed

Description (incidence and severity):

No test item-related effects on T4 concentrations in plasma were observed in the F0 animals up to 1000 mg/kg bw/day. The F0 TSH findings will be added when available.

Urinalysis findings:

no effects observed

Description (incidence and severity):

There were no effects on urinalysis parameters in the F0 animals up to 1000 mg/kg bw/day. All values were within normal biological variation when compared with the control group.

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

For the F0 animals, there were no behaviour changes mentioned in the study results for these parameters: gait and posture, presence of clonic or tonic movements, stereotypy, or bizarre behaviour up 1000 mg/kg bw/day, as assessed as part of the detailed clinical examinations.

Immunological findings:

not examined

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 the F0 animals, there were test item-related and adverse effects in the kidney at 1000 mg/kg bw/day in both sexes and at 300 mg/kg bw/day in females, primarily based on the tubular basophilia. The collective renal findings across both doses included tubular basophilia (minimal to moderate), tubular dilatation (minimal to mild), mononuclear cell infiltration (minimal to mild), papillary cellular debris (minimal), mineralisation (minimal to mild), and (in males only and not relevant to humans) minimal to mild accumulation of hyaline droplets in cortical tubules.

Tubular basophilia comprised cortical tubules lined by epithelial cells with cytoplasm that was reduced in amount and/or more basophilic than normal, with nuclei that were larger than normal with dispersed chromatin and with occasional degenerate cells. There also was fibrosis in the basement membranes and surrounding interstitial tissue. Some foci included interstitial mononuclear cell infiltration and/or dilatation of basophilic tubules, that were recorded as separate findings. Papillary cellular debris comprised amorphous or globular, slightly eosinophilic deposits in the lumen of papillary tubules, and/or focal increased cellularity of the epithelium of individual papillary tubules.

Tubular basophilia in the kidney at the mild or moderate grades (considered adverse at mild or higher) occurred only at 1000 mg/kg bw/day in both sexes and at 300 mg/kg bw/day in females. Noting, the average grade of tubular basophilia at 300 and 1000 mg/kg bw/day was higher in females than in males, and papillary cellular debris was more prevalent in females at these doses.

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Description (incidence and severity):

Coagulation findings:
There were no effects on coagulation parameters in the F0 animals up to 1000 mg/kg bw/day. All values were considered to be within normal biological variation when compared with the control group.

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

No test item-related effects on maternal oestrous cycles were identified for the F0 animals up to 1000 mg/kg bw/day.

Reproductive function: sperm measures:

no effects observed

Description (incidence and severity):

No test item-related effects on sperm motility, sperm or spermatid counts, or sperm morphology were seen in the F0 males up to 1000 mg/kg bw/day.

Reproductive performance:

no effects observed

Description (incidence and severity):

No test item-related effects on maternal reproduction performance or maternal care were observed in the F0 animals up to 1000 mg/kg bw/day, as based on male and female reproductive (mating, fertility, and pregnancy) indices, gestation length, female post-implantation loss, and on observed deficiencies in maternal care.

Key result

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

300 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

read-across polysulphides

Sex:

male

Basis for effect level:

histopathology: non-neoplastic

Remarks on result:

other: Test item-related and adverse renal histopathology at 1000 mg/kg bw/day

Key result

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

100 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysuphides read across

Sex:

female

Basis for effect level:

histopathology: non-neoplastic

Remarks on result:

other: Test item-related and adverse renal histopathology from 300 mg/kg bw/day

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

male/female

Basis for effect level:

other: Reproductive function and performance (males / females treated 10 weeks pre-mating until SD 114+ / LD 21)

Remarks on result:

other: Lack of test item-related effects up to 1000 mg/kg bw/day

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

300 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS:
In the absence of mention in the study report results, the reviewer considers that milk was present in the F1 pup stomachs and there were no external gross abnormalities, based on daily observations through PND 4 and then PNDs 7, 14, and 21 up to 1000 mg/kg bw/day of parental F0 treatment.

F1 COHORTS:
Test item-related but non-adverse clinical signs were observed in the Cohorts 1A and 1B animals at 300 and 1000 mg/kg bw/day, but not at 100 mg/kg bw/day.

There was an increase in the incidence of salivation at 300 and 1000 mg/kg/day in the Cohort 1A and Cohort 1B animals.

This clinical sign was predominantly observed immediately post-dose, with only a few instances at the 0-1 hour post-dosing timepoint. The salivation was most likely due to the taste of the formulations, and thus considered non-adverse.

Dermal irritation (if dermal study):

not specified

Mortality / viability:

no mortality observed

Description (incidence and severity):

F1 PUPS AND COHORTS:
There were no unscheduled deaths in F1 pups or F1 Cohorts 1A and 1B animals up to 1000 mg/kg bw/day treatment (parental F0 or direct cohort).

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Test item-related but non-adverse effects on body weight and body weight gain were noted in male F1 pups at 1000 mg/kg bw/day. The effects in males at 100 and 300 mg/kg bw/day and in females up to 1000 mg/kg bw/day were considered unrelated to the test item.

At 1000 mg/kg bw/day, there was a 7% lower body weight gain for the F0 male pups when compared with the control group, and a 5% lower body weight by LD 21. The study report does not indicate this finding is adverse.

F1 COHORTS:
No test item-related effects on body weight or body weight gain were observed in the F1 Cohort 1A or Cohort 1B animals up to 1000 mg/kg bw/day. Any statistical significance seen was due to individual variation within the dose groups.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

F1 COHORTS:
No test item-related effects on food consumption were identified in the F1 Cohorts 1A or 1B animals up to 1000 mg/kg/day.

F1 PUPS:
Not relevant (nursing).

Food efficiency:

not examined

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

no effects observed

Description (incidence and severity):

F1 COHORTS:
Water consumption by F1 Cohort 1A and 1B animals was monitored by visual inspection of the water bottles. No inter-group differences were noted.

F1 PUPS:
Not relevant (nursing).

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Description (incidence and severity):

F1 COHORT 1A:
There were no effects on haematology parameters in the F1 Cohort 1A animals up to 1000 mg/kg bw/day. All values were within normal biological variation when compared with the controls.

F1 PUPS AND F1 COHORT 1B:
Not examined.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

There were no effects on clinical chemistry parameters in the F1 Cohort 1A animals up to 1000 mg/kg bw/day. All values were within normal biological variation when compared with the controls.

F1 PUPS AND F1 COHORT 1B:
Not examined.

Urinalysis findings:

no effects observed

Description (incidence and severity):

F1 COHORT 1A:
There were no effects on urinalysis parameters in the F1 Cohort 1A animals up to 1000 mg/kg bw/day. All values were within normal biological variation when compared with the controls.

F1 PUPS AND F1 COHORT 1B:
Not examined.

Sexual maturation:

no effects observed

Description (incidence and severity):

F1 COHORTS:
There were no test-item related effects on sexual maturation or the time to first oestrous cycle in F1 Cohorts 1A or 1B up to 1000 mg/kg bw/day.

F1 PUPS:
Not relevant / examined.

Anogenital distance (AGD):

no effects observed

Description (incidence and severity):

F1 PUPS:
No test item-related effects on AGD in either sex were observed on PND 1 up to 1000 mg/kg bw/day of parental F0 treatment..

F1 COHORTS:
Not relevant / examined for the F1 Cohort 1A and 1B animals.

Nipple retention in male pups:

no effects observed

Description (incidence and severity):

F1 PUPS:
No test item-related effects on nipple retention in male pups were observed on PND 13 up to 1000 mg/kg bw/day of parental F0 exposure.

F1 COHORTS 1A and 1B:
Not relevant / examined for the F1 Cohort 1A and 1B animals.

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS:
No test item-related mean organ weight differences were seen in the F1 pups up to 1000 mg/kg bw/day of parental F0 treatment, as compared to the control group. The kidneys were not required to be weighed in these pups.

F1 COHORT 1A:
Test item-related but non-adverse mean kidney and liver weight findings were noted in females at 300 and 1000 mg/kg bw/day. The findings in males up to 1000 mg/kg bw/day and in females at 100 mg/kg bw/day were assessed as unrelated to the test item.

For the kidney, the mean weight was higher at 300 and 1000 mg/kg bw/day in females, correlating with the minimal or mild tubular basophilia seen histologically (adverse at a mild grade at 1000 mg/kg bw/day). The maximum difference from controls in weight relative to body weight was +15% in females at 1000 mg/kg bw/day.

The mean liver weight was higher at all doses in males and at 300 and 1000 mg/kg bw/day in females, correlating with the hepatocellular basophilia and hypertrophy seen histologically (examined at 1000 mg/kg bw/day). The maximum difference from controls in weight relative to body weight was +15% in females.

The kidney and liver weight findings are not identified as adverse in the study or pathology reports.

Please see Table 16 below.

F1 COHORT 1B:
There were test item-related but non-adverse mean kidney weights in females at 1000 mg/kg bw/day, liver weights in females at all doses, and liver weights in males at 1000 mg/kg bw/day. Male kidney weights up to 1000 mg/kg bw/day and all organ weights, except for the female liver, at 100 and 300 mg/kg bw/day were considered unrelated to the test item.

For the kidney, the mean weight was higher in females at 1000 mg/kg bw/day. The maximum difference from controls in weight relative to body weight was +13% at this dose.

The mean liver weight was higher in females at all doses and in males at 1000 mg/kg bw/day. The maximum difference from controls in weight relative to body weight was +21% in females at 1000 mg/kg bw/day.

These kidney and liver weight findings are not identified as adverse in the study or pathology reports. Noting that, per protocol, F1 Cohort 1B tissue samples were collected and processed to paraffin blocks, but not subject to microscopic examination.

Please see Table 17 below.

Gross pathological findings:

no effects observed

Description (incidence and severity):

F1 PUPS: [no effects observed]
There were no gross abnormalities in the pups culled / necropsied on PND 4 or in the F1 unselected pups necropsied on PNDs 22-24.

F1 COHORTS:
No test item-related gross findings were identified for the F1 Cohort 1A and 1B animals up to 1000 mg/kg bw/day. Any findings were generally of the nature commonly observed in this strain of rat at the ages concerned, most were infrequent, and none had a microscopic correlate.

Histopathological findings:

effects observed, treatment-related

Description (incidence and severity):

F1 COHORT 1A:
In the F1 Cohort 1A animals, there were test item-related and adverse effects in the kidney at 1000 mg/kg bw/day in females, primarily based on minimal to mild tubular basophilia (considered adverse at mild or higher). At this dose, the collective kidney findings across both sexes included tubular basophilia (minimal to mild), tubular dilatation (minimal to mild), mononuclear cell infiltration (minimal), papillary cellular debris (minimal), medullary mineralisation (minimal) and, in males only and not relevant to humans, minimal accumulation of hyaline droplets in cortical tubules.

Test item-related increases in tubular basophilia and medullary mineralisation occurred at 300 and 1000 mg/kg bw/day (in a dose level-related fashion). Tubular basophilia was assigned minimal or mild grade (adverse at mild or higher), indicating this finding was less severe than in the F0 animals. Medullary mineralisation comprised basophilic, non-birefringent amorphous deposits in the epithelium of, or between, tubules of the medulla, occasionally involving the outer papilla. The other kidney findings were increased at 1000 mg/kg bw/day only. Tubular basophilia at the mild grade and papillary cellular debris at the minimal grade occurred only in females at 1000 mg/kg bw/day indicating that the kidney findings were more apparent in females, as also evident in the F0 animals.

F1 PUPS AND F1 COHORT 1B:
Not examined, noting that F1 Cohort tissue samples were collected and processed to paraffin blocks for possible microscopic examination.

Other effects:

no effects observed

Description (incidence and severity):

COAGULATION FINDINGS:
F1 COHORT 1A: [no effects observed]
There were no effects on coagulation parameters in the F1 Cohort 1A animals up to 1000 mg/kg bw/day. All values were considered to be within normal biological variation when compared with the controls.

F1 PUPS AND F1 COHORT 1B:
Not examined.

ENDOCRINE FINDINGS:
F1 PUPS AND COHORTS:
No test item-related effects on T4 concentrations in plasma were observed in the F1 pups or in the Cohorts 1A or 1B animals up to 1000 mg/kg bw/day (parental F0 or cohort). The cohort animal TSH findings will be added when available. Samples for TSH analysis were not collected from the F1 pups.

OESTRUS CYCLE FINDINGS:
F1 COHORT 1A:
There were no test item-related effects on maternal oestrous cycles for the Cohort 1A animals up to 1000 mg/kg bw/day.

F1 AND F1 COHORT 1B:
Not examined.

SPERM FINDINGS:
F1 Cohort 1A:
There were no test item-related effects on sperm motility, sperm or spermatid counts, or sperm morphology in the F1 Cohort 1A males up to 1000 mg/kg bw/day.

F1 PUPS AND F1 COHORT 1B:
Not examined.

OVARIAN FOLLICLE COUNTS:
F1 COHORT 1A:
There were no test item-related effects on the ovarian follicle counts in the F1 Cohort 1A females up to 1000 mg/kg bw/day.

F1 AND F1 COHORT 1B:
Not examined.

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

F1 COHORTS:
For the F1 Cohort 1A and 1B animals, no behaviour changes were mentioned in the study results for these parameters: gait and posture, presence of clonic or tonic movements, stereotypy, or bizarre behaviour up 1000 mg/kg bw/day, as assessed as part of the detailed clinical examinations.

F1 PUPS:
Not examined, see clinical signs for the F1 pups.

Developmental immunotoxicity:

no effects observed

Description (incidence and severity):

F1 COHORT 1A:
No test item-related effects on immunophenotypic expression in the spleen were observed in F1 Cohort 1A animals treated up to 1000 mg/kg bw/day, as compared to the control group. No dose- or sex-dependent effects were observed for any immune cell populations, as expressed as a percentage of total lymphocytes.

F1 PUPS AND F1 COHORT 1B:
Not examined.

Key result

Dose descriptor:

NOAEL

Remarks:

systemic

Generation:

F1

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

male/female

Basis for effect level:

other: F1 pup systemic (potentially exposed in utero / during lactation PNDs 0-21)

Remarks on result:

other: Lack of test item-related and adverse effects up to 1000 mg/kg bw/day of parental treatment

Key result

Dose descriptor:

NOAEL

Remarks:

reproductive / developmental

Generation:

F1

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

male/female

Basis for effect level:

other: F1 pup reproductive function / developmental (potentially exposed in utero / during lactation PNDs 0-21)

Remarks on result:

other: Lack of test item-related effects up to 1000 mg/kg bw/day of parental treatment.

Key result

Dose descriptor:

NOAEL

Remarks:

systemic

Generation:

F1 (cohort 1A)

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

male

Basis for effect level:

other: Systemic (treated PNDs 21-90)

Remarks on result:

other: Lack of test item-related and adverse effects up to 1000 mg/kg bw/day

Key result

Dose descriptor:

NOAEL

Remarks:

systemic

Generation:

F1 (cohort 1A)

Effect level:

300 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

female

Basis for effect level:

histopathology: non-neoplastic

Remarks on result:

other: Test item-related and adverse renal histopathology at 1000 mg/kg bw/day

Key result

Dose descriptor:

NOAEL

Remarks:

reproductive

Generation:

F1 (cohort 1A)

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

male/female

Basis for effect level:

other: Reproductive function (treated PNDs 21-90)

Remarks on result:

other: Lack of test item-related effects up to 1000 mg/kg bw/day

Key result

Dose descriptor:

NOAEL

Remarks:

systemic

Generation:

F1 (cohort 1B)

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

male/female

Basis for effect level:

other: Systemic (treated PNDs 21-97)

Remarks on result:

other: Lack of test item-related and adverse effects up to 1000 mg/kg bw/day

Key result

Dose descriptor:

NOAEL

Remarks:

reproductive

Generation:

F1 (cohort 1B)

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

polysulphides read across

Sex:

male/female

Basis for effect level:

other: Reproductive function (treated PNDs 21-97)

Remarks on result:

other: Lack of test item-related effects up to 1000 mg/kg bw/day

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

1 000 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Key result

Reproductive effects observed:

no

Table 14. F0: Summary group mean organ weight data at scheduled euthanasia

	Males				Females
Group:	1	2	3	4	1	2	3	4
Dose (mg/kg/day):	0	100	300	1000	0	100	300	1000
No. animals examined:	25	25	25	25	25	25	25	25
Terminal Body Weight (No. weighed)	(25)	(25)	(25)	(25)	(21)	(23)	(23)	(23)
Absolute value (g)	490	499	478	465	284	277	281	287
Kidney (No. weighed)	(25)	(25)	(25)	(25)	(21)	(23)	(23)	(24)
Absolute value (g)	2.82	2.81	2.74	3.14**	2.16	2.08	2.28	2.76++
% of body weight	0.576	0.567	0.576	0.675**	0.758	0.755	0.812**	0.963**
% of brain weight	132	131	129	147	110	107	117	144
Liver (No. weighed)	(25)	(25)	(25)	(25)	(21)	(23)	(23)	(24)
Absolute value (g)	16.9	18.0	17.7	18.4	15.8	15.6	16.1	17.9**
% of body weight	3.43	3.61	3.69*	3.94**	5.56	5.65	5.74	6.21++
% of brain weight	787	841	831	863	806	805	826	930

Anova & Dunnett: * = p ≤ 0.05; ** = p ≤ 0.01

Kruskal-Wallis & Dunn: ++ = p ≤ 0.01

% of brain weight not analysed statistically

Group mean values are rounded to 3 significant figures. Statistical significance is based on unrounded data.

 

Table 15. F0: Summary group test item-related microscopic findings at scheduled euthanasia

	Males				Females
Group:	1	2	3	4	1	2	3	4
Dose (mg/kg/day):	0	100	300	1000	0	100	300	1000
No. animals examined:	25	25	25	25	25	25	25	25
Kidney (No. Examined)	(25)	(25)	(25)	(25)	(25)	(25)	(25)	(25)
Tubular basophilia^a	10	7	20	25	0	2	25	25
Minimal	10	7	20	6	0	2	15	0
Mild	0	0	0	18	0	0	10	17
Moderate	0	0	0	1	0	0	0	8
Mononuclear cell infiltration	13	18	19	25	5	7	25	25
Minimal	13	18	19	24	5	7	25	25
Mild	0	0	0	1	0	0	0	0
Tubular dilatation	6	9	11	18	1	0	3	24
Minimal	5	9	11	16	1	0	3	22
Mild	1	0	0	2	0	0	0	2
Cellular debris, papilla, minimal	0	0	1	5	0	0	17	25
Mineralisation, papilla	1	2	1	8	2	3	5	6
Minimal	1	2	1	7	2	3	5	6
Mild	0	0	0	1	0	0	0	0
Accumulation, cortical, hyaline droplets	0	10	7	17	0	0	0	0
Minimal	0	8	4	9	0	0	0	0
Mild	0	2	3	8	0	0	0	0
Liver (No. Examined)	(25)	(5)	(9)	(25)	(25)	(1)	(1)	(25)
Centrilobular hepatocellular hypertrophy, minimal	0	0	0	4	2	0	0	14
Increased hepatocellular basophilia, minimal	1	0	0	6	2	0	0	12
Jejunum (No. Examined)	(25)	–	–	(25)	(25)	–	–	(25)
Villous vacuolation	0	–	–	21	0	–	–	20
Minimal	0	–	–	12	0	–	–	15
Mild	0	–	–	8	0	–	–	5
Moderate	0	–	–	1	0	–	–	0
Ileum (No. Examined)	(25)	–	–	(25)	(25)	–	–	(25)
Villous vacuolation	0	–	–	2	0	–	–	0
Mild	0	–	–	1	0	–	–	0
Moderate	0	–	–	1	0	–	–	0
Mesenteric lymph node (No. Examined)	(25)	–	–	(25)	(25)	(2)	(2)	(25)
Vacuolation	0	–	–	5	0	0	1	9
Minimal	0	–	–	5	0	0	1	3
Mild	0	–	–	0	0	0	0	5
Moderate	0	–	–	0	0	0	0	1
Gut-associated lymphoid tissue (No. Examined)	(24)	–	–	(23)	(23)	–	–	(23)
Vacuolation, minimal	0	–	–	0	0	–	–	1

^a Reported as adverse for males at 1000 mg/kg bw/day and females from 300 mg/kg bw/day

Table 16. F1 Cohort 1A: Summary group mean organ weight data at scheduled euthanasia

	Males				Females
Group:	1	2	3	4	1	2	3	4
Dose (mg/kg/day):	0	100	300	1000	0	100	300	1000
No. animals examined:	20	20	20	20	20	20	20	20
Terminal Body Weight (No. weighed)	(20)	(19)	(19)	(20)	(20)	(20)	(20)	(20)
Absolute value (g)	414	405	396	384	223	219	220	225
Kidney (No. weighed)	(20)	(20)	(20)	(20)	(20)	(20)	(20)	(20)
Absolute value (g)	2.75	2.64	2.55	2.73	1.61	1.61	1.68	1.87**
% of body weight	0.665	0.656	0.643	0.712	0.723	0.738	0.762*	0.828**
% of brain weight	133	129	124	133	85.9	86.8	89.2	99.2
Liver (No. weighed)	(20)	(20)	(20)	(20)	(20)	(20)	(20)	(20)
Absolute value (g)	16.6	17.3	17.0	17.7	8.92	8.89	9.40	10.4**
% of body weight	4.02	4.25*	4.25*	4.59**	4.01	4.06	4.27*	4.62**
% of brain weight	805	842	825	862	475	478	500	554

Anova & Dunnett: * = p ≤ 0.05; ** = p ≤ 0.01

% of brain weight not analysed statistically

Group mean values are rounded to 3 significant figures. Statistical significance is based on unrounded data.

Table 17. F1 Cohort 1B: Summary group mean organ weight data at scheduled euthanasia

	Males				Females
Group:	1	2	3	4	1	2	3	4
Dose (mg/kg/day):	0	100	300	1000	0	100	300	1000
No. animals examined:	20	20	20	20	20	20	20	20
Terminal Body Weight (No. weighed)	(20)	(20)	(20)	(20)	(20)	(20)	(20)	(19)
Absolute value (g)	414	422	413	387	226	223	226	226
Kidney (No. weighed)	(20)	(20)	(20)	(20)	(20)	(20)	(20)	(20)
Absolute value (g)	2.68	2.60	2.65	2.66	1.62	1.64	1.67	1.84**
% of body weight	0.649	0.617	0.645	0.686	0.718	0.738	0.738	0.816**
% of brain weight	130	127	130	130	86.5	87.5	88.5	98.1
Liver (No. weighed)	(20)	(20)	(20)	(20)	(20)	(20)	(20)	(20)
Absolute value (g)	16.2	17.2	16.8	17.1	8.77	9.41	9.44	10.6**
% of body weight	3.91	4.07	4.08	4.41**	3.87	4.23*	4.16*	4.66**
% of brain weight	785	840	822	839	467	502	500	565

Anova & Dunnett: * = p ≤ 0.05; ** = p ≤ 0.01

% of brain weight not analysed statistically

Group mean values are rounded to 3 significant figures. Statistical significance is based on unrounded data.

Table 18. F1 Cohort 1A: Summary test item-related microscopic findings at scheduled euthanasia

	Males				Females
Group	1	2	3	4	1	2	3	4
Dose (mg/kg/day)	0	100	300	1000	0	100	300	1000
No. animals examined	25	25	25	25	25	25	25	25
Kidney (No. Examined)	(25)	(25)	(25)	(25)	(25)	(25)	(25)	(25)
Tubular basophilia^a	10	7	20	25	0	2	25	25
Minimal	10	7	20	6	0	2	15	0
Mild	0	0	0	18	0	0	10	17
Moderate	0	0	0	1	0	0	0	8
Mononuclear cell infiltration	13	18	19	25	5	7	25	25
Minimal	13	18	19	24	5	7	25	25
Mild	0	0	0	1	0	0	0	0
Tubular dilatation	6	9	11	18	1	0	3	24
Minimal	5	9	11	16	1	0	3	22
Mild	1	0	0	2	0	0	0	2
Cellular debris, papilla, minimal	0	0	1	5	0	0	17	25
Mineralisation, papilla	1	2	1	8	2	3	5	6
Minimal	1	2	1	7	2	3	5	6
Mild	0	0	0	1	0	0	0	0
Accumulation, cortical, hyaline droplets	0	10	7	17	0	0	0	0
Minimal	0	8	4	9	0	0	0	0
Mild	0	2	3	8	0	0	0	0
Liver (No. Examined)	(25)	(5)	(9)	(25)	(25)	(1)	(1)	(25)
Centrilobular hepatocellular hypertrophy, minimal	0	0	0	4	2	0	0	14
Increased hepatocellular basophilia, minimal	1	0	0	6	2	0	0	12
Jejunum (No. Examined)	(25)	–	–	(25)	(25)	–	–	(25)
Villous vacuolation	0	–	–	21	0	–	–	20
Minimal	0	–	–	12	0	–	–	15
Mild	0	–	–	8	0	–	–	5
Moderate	0	–	–	1	0	–	–	0
Ileum (No. Examined)	(25)	–	–	(25)	(25)	–	–	(25)
Villous vacuolation	0	–	–	2	0	–	–	0
Mild	0	–	–	1	0	–	–	0
Moderate	0	–	–	1	0	–	–	0
Mesenteric lymph node (No. Examined)	(25)	–	–	(25)	(25)	(2)	(2)	(25)
Vacuolation	0	–	–	5	0	0	1	9
Minimal	0	–	–	5	0	0	1	3
Mild	0	–	–	0	0	0	0	5
Moderate	0	–	–	0	0	0	0	1
Gut-associated lymphoid tissue (No. Examined)	(24)	–	–	(23)	(23)	–	–	(23)
Vacuolation, minimal	0	–	–	0	0	–	–	1

^a Reported as adverse for females at 1000 mg/kg bw/day

Conclusions:

In the EOGRTS for bis[3-(triethoxysilyl)propyl]polysulfides conducted according to OECD Test Guideline 443 and in compliance with GLP, four groups of Wistar Han rats were investigated: F0 (parental), F1 pups, F1 Cohort 1A, and F1 Cohort 1B, with the latter added to primarily assess endocrine and reproductive tissues via necropsy and organ weights. The F0 and cohort groups were administered the test substance at 0, 100, 300, and 1000 mg/kg bw/day (corn oil vehicle), with the F1 pups potentially exposed in utero or during lactation. Based on the findings, the overall study NOAELs were identified as follows:
- Systemic, males: 300 mg/kg bw/day, based on test item-related and adverse kidney histopathology in F0 males at 1000 mg/kg bw/day
- Systemic, females: 100 mg/kg bw/day, based on test item-related and adverse kidney histopathology in F0 females from 300 mg/kg bw/day
- Reproduction: At least 1000 mg/kg bw/day, based on the lack of test item-related: reproductive effects in the F0, F1 Cohort 1A, and F1 Cohort 1B animals, and reproductive / developmental effects in the F1 pups.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Based on the reliable OECD Test Guideline 443 study

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

In the key EOGRTS study with bis[3-(triethoxysilyl)polysulfides (CAS No. 211519-85-6, EC No. 915-673-4) conducted according to OECD Test Guideline 443 and in compliance with GLP (Charles River Laboratories, 2022), Wistar Han rats (F0, F1 Cohort 1A, and F1 Cohort 1B) were administered the test substance at 0, 100, 300, and 1000 mg/kg bw/day (corn oil vehicle), with 25 animals/sex/dose in the F0 cohort and 20 animals/sex/dose in the two F1 cohorts. The F1 pups were culled on Postnatal Day (PND 4) to yield litters of 4/sex/litter (as feasible), with the two F1 cohorts selected on PND 21. The treatment durations varied by F0 and cohort group as follows, with F1 pups potentially exposed in utero and during lactation until PND 21:

- F0, males: 10 weeks prior to mating and continuing throughout and after mating until the day before necropsy from Study Day (SD) 114

- F0, females: 10 weeks prior to mating and continuing throughout mating and gestation until at least Lactation Day (LD) 21, necropsied LDs 22-24

- F1 Cohort 1A: From PND 21 until the day before necropsy (at least PND 90)

- F1 Cohort 1A: From PND 21 until the day before necropsy (at least PND 97)

 

For all three adult cohorts, the parameters evaluated included mortality, clinical observations (cageside, pre- and post-dosing, and detailed), body weights, food consumption, water consumption (visual), oestrous cycles, and a complete macroscopic examination. Additional parameters by cohort(s) included:

- F0: Data to determine reproductive indices (mating, fertility, and pregnancy), female post-implantation loss, gestation length, and any deficiencies in maternal care

- F0 and F1 Cohort 1A, both sexes: Haematology, clinical chemistry, coagulation, serum thyroxine (T4) and/or thyroid stimulating hormone (TSH) levels (TSH results not yet available), and urinalysis

. At necropsy, a full list of organ / tissues was subject to organ weights, gross pathology, histology and histopathology.

- F0 and F1 Cohort 1A, males: Sperm motility, sperm and spermatid counts and, at 0 and 1000 mg/kg bw/day, sperm morphology analysis

- F1 Cohorts 1A and 1B: Sexual maturation

- F1 Cohort 1A only: Ovarian follicle counts, spleen immunophenotyping

- F1 Cohort 1B only: At necropsy, a subset of organ / tissues (primarily endocrine and reproductive but also, for example, the kidney) was subject to organ weights and gross pathology, with tissues collected and processed to paraffin blocks for possible histopathologic examination. Since the in-life phase for this study ended on 21 July 2021 (at approximately the same time as ECHA issued its “Critical aspects for designing and conducting extended one-generation reproductive toxicity (EOGRT) studies under REACH”, processed tissue samples were retained for possible histopathology, but a microscopic examination for the kidney in F1 Cohort 1B animals was not performed (see F1 Cohort 1A kidney results below).

 

In F1 litters or pups, the following parameters were evaluated: numbers of live and dead pups (liver birth index), sex ratio, daily number of live pups (litter size, viability index), daily presence/absence of milk in pup stomachs (as feasible), visible external abnormalities, body weights, anogenital distance (AGD), male nipple retention, serum thyroxine (T4) and/or thyroid stimulating hormone (TSH) levels in subsets of the culled pups necropsy on PND 4 and the unselected pups at necropsy on PNDs 22-24, number of pups surviving to LD 21 (lactation index), external exam prior to necropsy, macroscopic exam for the culled pups and unselected pups, and organ weights for the same subset of unselected pups as the T4 / TSH analysis.

 

The systemic findings considered test item-related and adverse (kidney histopathology in the F0 cohort and females in F1 Cohort 1A) are discussed below. For all other parameters in the three cohorts (F0, F1 Cohort 1A, F1 Cohort 1B) and for the F1 pups, there were no effects observed or the findings were considered unrelated to the test item.

 

In the F0 animals, there was adverse histopathology (mild or higher tubular basophilia) in the kidney of both sexes at 1000 mg/kg/day and of females at 300 mg/kg bw/day, primarily based on the tubular basophilia. The collective renal findings across both doses included tubular basophilia (minimal to moderate), tubular dilatation (minimal to mild), mononuclear cell infiltration (minimal to mild), papillary cellular debris (minimal), mineralisation (minimal to mild), and (in males only and not relevant to humans) minimal to mild accumulation of hyaline droplets in cortical tubules. Tubular basophilia comprised cortical tubules lined by epithelial cells with cytoplasm that was reduced in amount and/or more basophilic than normal, with nuclei that were larger than normal with dispersed chromatin and with occasional degenerate cells. There also was fibrosis in the basement membranes and surrounding interstitial tissue. Some foci included interstitial mononuclear cell infiltration and/or dilatation of basophilic tubules, which were recorded as separate findings. Papillary cellular debris comprised amorphous or globular, slightly eosinophilic deposits in the lumen of papillary tubules, and/or focal increased cellularity of the epithelium of individual papillary tubules. The tubular basophilia in the kidney (mild or moderate; mild and above considered adverse) was identified as adverse in both sexes at 1000 mg/kg bw/day and in females from 300 mg/kg bw/day. Noting, the average grade of tubular basophilia in females at 300 and 1000 mg/kg bw/day was higher in females than in males, and papillary cellular debris was more prevalent in females at these doses.

 

In the F1 Cohort 1A animals, there was adverse histopathology (mild tubular basophilia) in the female kidney at 1000 mg/kg bw/day. At this dose, the collective kidney findings across both sexes included tubular basophilia (minimal to mild), tubular dilatation (minimal to mild), mononuclear cell infiltration (minimal), papillary cellular debris (minimal), medullary mineralisation (minimal) and, in males only and not relevant to humans, minimal accumulation of hyaline droplets in cortical tubules. Test item-related tubular basophilia and medullary mineralisation were increased at 300 and 1000 mg/kg/day (in a dose level-related fashion). However, the tubular basophilia did not exceed the mild grade except for females at 1000 mg/kg bw/day, indicating that the changes for this sex and dose were adverse, but less marked than in the F0 animals (up to moderate at 1000 mg/kg bw/day). Medullary mineralisation in both sexes at all doses (no clear dose-response) comprised basophilic, non-birefringent amorphous deposits in the epithelium of, or between, tubules of the medulla, occasionally involving the outer papilla. The other findings in the kidney were increased only at 1000 mg/kg bw/day. Tubular basophilia at the mild grade and minimal papillary cellular debris only occurred in females at this dose, indicating that the kidney findings (apart from male hyaline droplet accumulation) were more apparent in females, as was seen in the F0 animals. Except for the mild tubular basophilia in females at 1000 mg/kg bw/day, the observed renal histology for the F1 Cohort 1A was considered non-adverse.

 

For the F1 Cohort 1B animals, no test item-related and adverse kidney findings (necropsy, organ weights) were observed up to 1000 mg/kg bw/day. As previously indicated, tissue samples including the kidney were collected and processed but, per protocol (prior to July 2021), a renal microscopic examination was not performed for these animals.

 

In summary, the overall study NOAELs in the EOGRTS (OECD Test Guideline 443) for bis[3-(triethoxysilyl)polysulfides in Han Wistar rats across the four cohorts (F0, F1 pups, F1 Cohort 1A, F1 Cohort 1A) were identified as follows:

- Systemic, males: 300 mg/kg bw/day, based on test item-related and adverse kidney histopathology in F0 males at 1000 mg/kg bw/day

- Systemic, females: 100 mg/kg bw/day, based on test item-related and adverse histopathology findings in F0 females from 300 mg/kg bw/day

- Reproduction: At least 1000 mg/kg bw/day, based on the lack of: reproductive findings in the F0, Cohort 1A, and Cohort 1B animals and reproductive / developmental findings in the F1 pups.

Effects on developmental toxicity

Description of key information

In a prenatal developmental toxicity study in pregnant female Wistar rats conducted according to OECD Test Guideline 414 and in compliance with GLP,  the NOAELs for maternal toxicity and fetal toxicity were concluded to be 1000 mg/kg/day based on no major toxicological findings in the females or fetuses treated orally by gavage from gestation day 5 to 19 (BSL Bioservice 2013).

In a prenatal developmental toxicity study in rabbits conducted according to OECD Test Guideline 414 and in compliance with GLP, the NOAELs for maternal toxicity and developmental toxicity were concluded to be at least 1000 mg/kg bw/day based on no observed adverse effects in pregnant New Zealand White female rabbit treated orally by gavage from days 7 to days 28 post-coitum as well as in any of the fetuses (Charles River Laboratories 2021)

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January to July 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Germany
- Age at study initiation: 11 to 12 weeks
- Weight at study initiation: Males 296-344g Females 187-222g
- Fasting period before study: No
- Housing: individually in IVC cages (except during the mating period when two females were paired with one male), type III H, polysulphone cages
- Diet: Altromin 1324 maintenance diet ad libitum
- Water: tap water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 45-65
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To: 10 January 2013 to 15 May 2013

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was weighed into a tared plastic vial on a precision balance and then dissolved in olive oil.

VEHICLE
- Justification for use and choice of vehicle: The vehicle was selected as suggested by the sponsor based on the test item’s characteristics and testing guideline
- Concentration in vehicle: 0, 25, 75, 250 mg/ml
- Amount of vehicle (if gavage): 4 ml/kg
- Lot/batch no. : BCBH9319V

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The assessment of homogeneity as well as a determination of the nominal concentration of the test item in the vehicle was performed at various intervals.
Samples for analysis of the dose formulations of the test item in the vehicle (nominal concentration) were taken from all groups in the first and last week of the study for all doses (8 samples in total).
Samples for homogeneity were taken from the top, middle and bottom of the high dose and low dose preparation. Samples were taken in the first and last week of the study (18 samples in total).
Samples for stability analysis were taken in the first week of the study, 0 hours after the preparation and another sample 6 hours after the preparation (at room temperature), from high, medium, and low dose formulations (6 samples).
From all formulation samples aliquots of 10 mL were stored at -20° C and were analysed after completion of the in-life phase of the study.

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage: 1:2
- Length of cohabitation: not stated
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- Any other deviations from standard protocol: not stated

Duration of treatment / exposure:

From gestational day 5 to gestational day 19 inclusive.

Frequency of treatment:

Once daily

Duration of test:

< 28 days

Dose / conc.:

100 mg/kg bw/day

Remarks:

Low Dose (LD)

Dose / conc.:

300 mg/kg bw/day

Remarks:

Medium Dose (MD)

Dose / conc.:

1 000 mg/kg bw/day

Remarks:

High Dose (HD)

No. of animals per sex per dose:

25

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The highest dose level was chosen with the aim of inducing toxic effects, but not death or severe suffering. Thereafter, a descending sequence of dose levels was selected with a view to demonstrate any dose-related response and a NOAEL.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: gestational days 0, 5, 8, 11, 14, 17 and 20

FOOD CONSUMPTION: Yes
- Time schedule for examinations: gestational days 5, 8, 11, 14, 17 and 20


WATER CONSUMPTION: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: general macroscopic examination

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: Yes: [half per litter]

Statistics:

A statistical assessment of the results of the body weight, food consumption was performed by comparing values of dosed with control animals using a one-way ANOVA and a post-hoc Dunnett's Test. Fetal evaluation parameters including external, visceral, craniofacial and skeletal parameters were analysed using a Chi-square test.

Clinical signs:

no effects observed

Description (incidence and severity):

No test item-related clinical signs were observed in any of the treated groups compared with controls. A few spontaneous clinical signs, including alopecia on the front leg or abdomen and moderate salivation, occurred infrequently, similarly in the control group, and/or in a manner that was not dose-related.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

All animals survived to the scheduled necropsy.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Body weight and body weight gain were unaffected by test item administration during gestation when compared to controls, with the exception of a statistically significant increase in body weight gain during gestation day interval 17-20 in LD and HD groups.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

No treatment-related effect on food consumption was observed during gestation compared with controls. Food consumption increased during the course of the study in all groups, consistent with the increases seen in body weight and body weight gain.

Food efficiency:

not examined

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

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

No statistically significant treatment-related effects were observed for terminal body weight, gravid uterine weight, and adjusted maternal weight.

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Description (incidence and severity):

No statistically significant treatment-related effects were observed for group mean number of live fetuses and dead fetuses

Changes in pregnancy duration:

no effects observed

Changes in number of pregnant:

no effects observed

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: No effects attributable to treatment noted at any dose.

Key result

Abnormalities:

no effects observed

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

No statistically significant treatment-related effects were observed for group mean number of live fetuses and dead fetuses

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

no effects observed

External malformations:

no effects observed

Description (incidence and severity):

Fetal external examination on the day of terminal sacrifice revealed a domed head in one fetus of the LD group. No external treatment-related effects were observed in any of the other treated or control group fetuses or the remaining fetuses from the LD group.

Skeletal malformations:

effects observed, non-treatment-related

Description (incidence and severity):

An increase in the incidence of incomplete ossification of frontal skull in MD and HD, interparietal skull in LD and MD, parietal skull in LD, MD and HD, 1st sternebra in LD, 4th Sternebra in LD and HD and xiphoid in LD was observed when compared with controls. There were also statistically significant increase in the incidence of unossified 4th metacarpal (B) in LD, all forelimb phalanx (B) in LD and MD, all hindlimb phalanx (B) in LD and HD, 1st metatarsal (B) in LD and HD and statistically significant decrease in fused parietal and frontal skull in LD, MD and HD. Due to the lack of dose dependency and consistency in these findings, these observations are not considered adverse or treatment-related.
A decrease in the incidence of hemorrhagic ear- cochlea (B) in HD and slightly enlarged lateral ventricles (B) in MD group. Since, these findings were considered to be minor variations and frequencies were even less in numbers compared to controls. Therefore, these findings are not to be considered as treatment-related and solely spontaneous in nature.

Visceral malformations:

effects observed, non-treatment-related

Description (incidence and severity):

An increase in the incidence of hemorrhagic bladder wall and convoluted right ureter in the MD group and statistically significant decrease in hemorrhagic heart in LD and extra tissue at median liver lobe in LD and HD. Since these visceral abnormalities were not observed to occur in a dose-response relationship, these findings were considered to be spontaneous in nature.

Other effects:

not specified

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: No findings attributable to treatment noted at any dose.

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Conclusions:

In a prenatal developmental toxicity study in pregnant female Wistar rats with bis[3-(triethoxysilyl)polysulfides conducted according to OECD Test Guideline 414 and in compliance with GLP, the NOAEL for maternal toxicity and fetal toxicity was concluded to be 1000 mg/kg/day based on no major toxicological findings in the females or fetuses treated orally by gavage from gestation day 5 to 19.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Species:

other: rats and rabbits

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

The key prenatal developmental toxicity study in rats with bis[3-(triethoxysilyl)propyl]polysulfides was conducted according to OECD Test Guideline 414 and in compliance with GLP. In this study, the test material was administered orally to pregnant female Wistar rats at doses of 0, 100, 300 or 1000 mg/kg bw/day from gestation day 5 to 19. All maternal animals survived to the scheduled necropsy. No test item-related clinical signs were observed in any of the treated groups compared with controls. Body weight and body weight gain were unaffected by test item administration during gestation when compared to controls, with the exception of a statistically significant increase in body weight gain during gestation day interval 17-20 in the low dose and high dose groups. No treatment-related effect on food consumption was observed during gestation compared with controls. Food consumption increased during the course of the study in all groups, consistent with the increases seen in body weight and body weight gain. No statistically significant treatment-related effects were observed for terminal body weight, gravid uterine weight, adjusted maternal weight, number of corpora lutea and implantations, and percent preimplantation loss compared with controls. No statistically significant treatment-related effects were observed for group mean number of live fetuses and dead fetuses, resorptions, post implantation loss, male and female fetuses or sex ratio compared to controls. No statistically significant treatment-related effects were observed on a per litter basis including group litter mean weight, number of males, number of females, total number of pups, sex ratio, total litter weight, male litter weight and female litter weight when compared to controls. Significant changes in foetal morphology were observed but due to the lack of dose dependency and consistency, there were not considered to be adverse or treatment-related. The NOAELs for both maternal toxicity and foetal toxicity in Wistar rats were therefore determined to be at least 1000 mg/kg/day (BSL Bioservice, 2013).

 

In the key prenatal developmental toxicity study with bis[3-(triethoxysilyl)propyl]polysulfides in rabbits conducted according to OECD Test Guideline 414 and in compliance with GLP, the test material was administered orally to time-mated female New Zealand White rabbits from Days 7 to 28 post-coitum, inclusive. The dose levels were selected to be 0, 100, 300, and 1000 mg/kg bw/day based on the results of the dose range finder. Two females were sacrificed in extremis during the study period, due to circumstances unrelated to treatment with the test item. No maternal or developmental toxicity was observed in any of the dose groups, with the NOAELs for these endpoints concluded to be at least 1000 mg/kg bw/day (Charles River Laboratories, 2021).

Toxicity to reproduction: other studies

Link to relevant study records

Reference

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

September 1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Four-Day Uterine Weight Assay, Screening Methods in Pharmacology

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 440: Uterotrophic bioassay in rodents, a short-term screening test for oestrogenic properties

Version / remarks:

2017

Deviations:

yes

Remarks:

Only one treatment group, limited information on the experimental conditions

Principles of method if other than guideline:

Based on the effect of estrogen to increase the protein synthesis and consequently to increase the uterine weights and water retention in the uterine tissue.

GLP compliance:

yes

Type of method:

in vivo

Species:

mouse

Strain:

NMRI

Sex:

female

Details on test animals or test system and environmental conditions:

animal weights: 10 - 12 g

Route of administration:

oral: gavage

Vehicle:

peanut oil

Details on exposure:

Test substance: 50 ml /kg bw by gavage
Positive control: 0.001 /kg bw estradiol (as estradiolbenzoate) intramuscular
Negative control: 50 ml / kg bw peanut oil by gavage
Negative control: 10 ml /kg bw peanut oil intramuscular

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

3 days

Frequency of treatment:

3 times, each after 24 h

Duration of test:

4 days

Dose / conc.:

50 other: ml/kg bw

Remarks:

Basis:
nominal conc.
test substance (oral)

Dose / conc.:

0.001 other: µg / kg bw estradiol

Remarks:

Basis:
nominal conc.
estradiol as positive control (i.m.)

Dose / conc.:

50 other: ml/kg bw

Remarks:

Basis:
nominal conc.
peanut oil as negative control (oral)

Dose / conc.:

10 other: ml/kg bw

Remarks:

Basis:
nominal conc.
peanut oil as negative control (i.m.)

No. of animals per sex per dose:

10 animals

Control animals:

yes, concurrent vehicle

other: positive control

Details on study design:

On day 4 the animals were sacrificed. The wet and dry (dried at 100°C , 24h) weights of uteri were determined

Statistics:

Student's t-test

Dose descriptor:

other: uteri weights

Remarks:

mean

Effect level:

12.1 other: mg wet weight (2.2 mg dry)

Based on:

test mat.

Remarks:

oral

Sex:

female

Dose descriptor:

other: uteri weights

Remarks:

mean

Effect level:

12.2 other: mg wet weight (2.0 mg dry)

Based on:

other: negative control

Remarks:

oral

Sex:

female

Dose descriptor:

other: uteri weights

Remarks:

mean

Effect level:

52.7 other: mg wet weight (7.5 mg dry)

Based on:

other: positive control, estradiol

Remarks:

i.m.

Sex:

female

Dose descriptor:

other: uteri weights

Remarks:

mean

Effect level:

14.7 other: mg wet weight (3.2 mg dry)

Based on:

other: vehicle

Remarks:

i.m.

Sex:

female

No effects in the test material and negative control group.
A statistical significant increase in the uteri wet and dry weights in the positive control.

Conclusions:

Based on the results of this four-day uterine weight assay, no increase in uterine weight was determined with the test item compared to the control group.

Additional information

A supporting, non-standard four-day uterine weight assay in mice is available, which reports no detectable increase in uterine weight following oral administration of the registered substance for 4 days (Laboratorium Für Pharmakologie und Toxikologie, 1983). Based on the results of the study, no oestrogenic potential is expected for this substance.

Justification for classification or non-classification

Based on the available data, bis[3-(triethoxysilyl)polysulfides is not classified for reproductive (fertility or developmental) toxicity according to Regulation (EC) No. 1272/2008.