Reaction mass of (2,4,6-trioxo-1,3,5-triazine-1,3,5(2H,4H,6H)-triyl)tri-2,1-ethanediyl triacrylate and 2-Propenoic acid, 1,1'-[[dihydro-5-(2-hydroxyethyl)-2,4,6-trioxo-1,3,5-triazine-1,3(2H,4H)-diyl]di-2,1-ethanediyl] ester

Endpoint summary

Description of key information

Data on Reaction mass og THEICTA and THEICDA target substance is not available. Thus, read-across has been applied using data from the source substance TMPTA (S2).

Oral exposure:

TMPTA was tested in an oral OECD 422 rat study from which a NOAEL of 30 mg/kg bw/day for local toxicity and a NOAEL of 300 mg/kg bw/day for systemic toxicity was observed for parental toxicity. LOAEL for local toxicity was 100 mg/kg bw/d based on adverse local effect in the stomach and forestomach of the animals. These effects were considered to be due to local irritation of the substance. 

For tris(2-hydroxyethyl) isocyanurate (may be formed by hydrolysis of THEICTA and THEICDA) a NOAEL of 1000 mg/kg bw/d was found from an OECD 422 oral rat study.

Based on these findings and due to the close structural relationship to TMPTA the NOAEL values for TMPTA are consider valid for Reaction mass of THEICTA and THEICDA (T) as well.

Thus, considering these data for read-across any further repeated dose toxicity testing of Reaction mass of THEICTA and THEICDA (T) is considered scientifically unjustified as gastrointestinal tract irritation of the substance would limit the dose level for testing, and as for TMPTA a dose level for achieving systemic toxicity would most probably not be achieved.

Dermal exposure: Based on long-term dermal toxicity studies in rats and mice using dose levels of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body, 5days/week for 2 years the following NOAELS were observed: NOAEL (systemic, rats and mice): ≥ 3 g/kg bw; LOAEL (local, rats): 0.3 mg/kg/d.

As TMPTA has been tested on two long-term studies according to the NTP standard protocol for long term/ carcinogenicity testing. Thus, valid NOAEL values for dermal toxicity have been generated for this substance.

As for oral testing of TMPTA the adverse local effect at the site of application limit the use of higher dose levels causing systemic effects.

Based on these findings and due to the close structural relationship the NOAEL value for TMPTA for local effect is considered applicable for Reaction mass of THEICTA and THEICDA as well

.

Inhalation:

No data or study available 

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Data on target substance not available. Thus, read-across has been applied using data from the source substance TMPTA (S2).
See further read-acoss justification in attached document to section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Se remarks:

Critical effects observed:

not specified

Executive summary:

No data is available for Reaction mass of THEICTA and THEICDA (T).

TMPTA (S2) was tested in an oral OECD 422 rat study from which a NOAEL of 30 mg/kg bw/day for local toxicity while a NOAEL of 300 mg/kg bw/day for systemic toxicity was observed for parental toxicity. LOAEL for local toxicity was 100 mg/kg bw/d based on adverse local effect in the stomach and forestomach of the animals. These effects were considered to be due to local irritation of the substance. 

For tris(2-hydroxyethyl) isocyanurate (S3) a NOAEL of 1000 mg/kg bw/d was found from an OECD 422 oral rat study.

Based on these findings and due to the close structural relationship the NOAEL values for TMPTA are considered applicable for Reaction mass of THEICTA and THEICDA as well.

Thus, considering these data for read-across any further repeated dose toxicity testing of Reaction mass of THEICTA and THEICDA is considered scientifically unjustified as gastrointestinal tract irritation of the substance would limit the dose level for testing, and as for TMPTA a dose level for achieving systemic toxicity would not be achieved.

Based on these findings and due to the close structural relationship to TMPTA the NOAEL value for TMPTA for systemic effect of 300 mg/kg bw/d is considered valid for of Reaction mass of THEICTA and THEICDA (T) as well.

Reference 2

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-03-02 to 2015-04-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed in accordance to OECD testing guideline with no deviation to study plan (See attached study report)

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

Principles of method if other than guideline:

NA

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

other: Rat: Crl:WI(Han) (outbred, SPF-Quality). Nulliparous and non-pregnant females and untreated animals were used at initiation of the study.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany (This species and strain of rat has been recognized as appropriate for general and reproduction toxicity studies. WIL Research Europe B.V. has general and reproduction/developmental historical data in this species from the same strain and source).
- Age at study initiation: Approximately 10-12 weeks
- Weight at study initiation: 220 g (female); 320 (male)
- Fasting period before study: no

- Housing:
- Pre-mating: Animals were housed in groups of 5 animals/sex/cage in Macrolon plastic cages (MIV type, height 18 cm).
- Mating Females: were caged together with males on a one-to-one-basis in Macrolon plastic cages (MIII type, height 18 cm).
- Post-mating: Males were housed in their home cage (Macrolon plastic cages, MIV type, height 18 cm) with a maximum of 5 animals/cage. Females were in dividually housed in Macrolon plastic cages (MIII type, height 18 cm).
- Lactation Pups were kept with the dam until termination in Macrolon plastic cages (MIII type, height 18 cm). During locomotor activity monitoring of the
dams the pups were kept warm in their home cage using bottles filled with warm water. In order to avoid hypothermia of pups, pups were not left without their dam or a bottle filled with warm water for longer than 30-40 minutes.

- Diet (ad libitum): pelleted rodent diet (SM R/M-Z from SSNIFF®Spezialdiäten GmbH, Soest, Germany).
- Water (ad libitum): Free access to tap-water
- Acclimation period: At least 5 days prior to start of treatment.
- Other: Diet, water, bedding and cage-enrichment/nesting material evaluation for contaminants and/or nutrients was performed according to facility standard procedures.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 24°C
- Humidity (%): 40 to 70%,
- Air changes (per hr): 10 room air changes/hour
- Photoperiod (hrs dark / hrs light): 12 hour light / 12 hour dark

Sterilized sawdust as bedding material (Lignocel S 8-15, JRS - J.Rettenmaier & Söhne GmbH + CO. KG, Rosenberg, Germany) and paper as cage-enrichment/nesting material (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom) were supplied. During locomotor activity monitoring, animals were housed individually in a Hitemp polycarbonate cage (Ancare corp., USA; dimensions: 48.3 x 26.7 x 20.3 cm) without cage-enrichment, bedding material, food and water.

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Remarks:

Polyethylene glycol 400, specific gravity 1.125

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
Formulations (w/w) were prepared daily within 5 hours prior to dosing and were homogenized to a visually acceptable level. Adjustment was made for specific gravity of the test substance and vehicle. No correction was made for the purity/composition of the test substance. Formulations were placed on a magnetic stirrer during dosing.

VEHICLE
- Concentration in vehicle: 6, 20, 60 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg bw
- Lot/batch no.: Polyethylene glycol 400, specific gravity 1.125 (Merck, Darmstadt, Germany).

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of dose preparations were taken at the Test Facility on two occasions during the treatment period (formulations were prepared and sampled on 04 and 31 March 2015). The samples were dispatched on dry ice to ABL where they were analyzed to assess accuracy of preparation (all groups) and homogeneity (lowest and highest concentration). In addition, stability in vehicle over 5 hours at room temperature protected from light was determined on samples (lowest and highest concentration) taken on 04 March 2015.

The accuracy of preparation was considered acceptable if the mean measured concentrations were 90-110% of the target concentration. Homogeneity was demonstrated if the coefficient of variation was ≤ 10%. Formulations were considered stable if the relative difference before and after storage was maximally 10%.

Duration of treatment / exposure:

Males were exposed for 29 days, i.e. 2 weeks prior to mating, during mating, and up to the day prior to scheduled necropsy. Females were exposed for 41-55 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation (up to the day prior to scheduled necropsy).

Frequency of treatment:

Once daily for 7 days per week, approximately the same time each day with a maximum of 6 hours difference between the earliest and latest dose.

Remarks:

Doses / Concentrations:
0, 30. 100, 300 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

10/sex/group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were selected based on the outcome of the previous dose range finding study with Wistar Han rats (Project 507633). TMPTA was administered by oral gavage, once daily for 14 consecutive days at dose levels of 100, 300 or 1000 mg/kg/day (5 animals/sex/dose level). Concurrent controls (5 animals/sex) received the vehicle, polyethylene glycol 400, alone. The most relevant effects in this 14-days dose range finding study included lower body weights in males at 1000 mg/kg/day, local toxicity at the stomach in both males and females from 100 mg/kg/day onwards, and slightly higher liver weights in females at 1000 mg/kg/day. Based on these data, the dose levels selected for the current, definitive study (Project 507632) were 30, 100 and 300 mg/kg/day.

- Rationale for animal assignment (if not random): random
- Rationale for selecting satellite groups: none included
- Post-exposure recovery period in satellite groups: NA
- Section schedule rationale (if not random): random

Positive control:

None included in the study design

Observations and examinations performed and frequency:

Parental animals (F0):

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
Each male and female was also observed for signs of toxicity immediately following dosing and at approximately 1 hour following dose administration.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily from treatment onwards up to the day prior to necropsy, detailed clinical observations were made for all animals. Once prior to start of
treatment and at weekly intervals during the treatment period this was also performed outside the home cage in a standard arena. These clinical observations were at least conducted immediately (0-30 min) after dosing, i.e. on the peak period of anticipated effects after dosing based on results of the dose range finding study (Project 507633). In this pilot study salivation was noted shortly after dosing. The time of onset, grade and duration of any observed sign was recorded. Signs were graded for severity and the maximum grade was predefined at 3 or 4. Grades were coded as slight (grade 1), moderate (grade 2), severe (grade 3) and very severe (grade 4). For certain signs, only its presence (grade 1) or absence (grade 0) was scored. In the data tables, the scored grades were reported, as well as the percentage of animals affected in summary tables.


BODY WEIGHT: Yes
- Time schedule for examinations: Males and females were weighed on the first day of exposure and weekly thereafter. Mated females were weighed on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum and on Days 1 and 4 of lactation.


FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
Weekly, except for males and females which were housed together for mating and for females without evidence of mating. Food consumption of mated females was measured on Days 0, 4, 7, 11, 14, 17 and 20 postcoitum and on Days 1 and 4 of lactation.


FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No


WATER CONSUMPTION:Subjective appraisal was maintained during the study, but no quantitative investigation was introduced as no treatment related effect was suspected.


OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the scheduled necropsies (study day 28 for males and lactation day 5 for females)
- Anaesthetic used for blood collection: isoflurane
- Animals fasted: Yes
- How many animals: 5 animals/sex/group
- Parameters were examined: Total leukocyte count (WBC), Erythrocyte count (RBC), Hemoglobin (HGB), Hematocrit (HCT), Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), Mean corpuscular hemoglobin concentration (MCHC), Platelet count (PLATELET), Prothrombin time (PT), Activated partial thromboplastin time (APTT), Reticulocyte count, Percent (RETIC), Absolute (RETIC ABSOLUTE), Mean Platelet Volume (MPV), Red cell distribution width (RDW), Hemoglobin Distribution Width (HDW), Differential leukocyte count: (Percent and absolute): Neutrophil (NEU), Lymphocyte (LYMPH), Monocyte (MONO), Eosinophil (EOS), Basophil (BASO), Large unstained cell (LUC), Platelet estimatea, Red cell morphology (RBC MORPHOLOGY).


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the scheduled necropsies (study day 28 for males and lactation day 5 for females)
- Animals fasted: Yes
- How many animals: 5 animals/sex/group
- Parameters were examined: Albumin, Total protein, Globulin [by calculation], Albumin/globulin ratio (A/G Ratio) [by calculation], Total bilirubin (Total Bili), Urea nitrogen, Creatinine, Alkaline phosphatase (ALP), Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Gamma glutamyltransferase (GGT), Glucose, Total cholesterol (Cholesterol), Calcium, Chloride, Phosphorus, Potassium, Sodium, Triglycerides (Triglyceride), Bile acids.


URINALYSIS: No


NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: FOB assessments were recorded for 5 animals/sex/group. The selected males were tested during Week 4 of treatment and the selected females were tested towards the end of the scheduled lactation period (all before blood sampling). These tests were performed after observation for clinical signs (incl. arena observation, if applicable).

The following tests were performed:
- hearing ability, pupillary reflex and static righting reflex (score 0 = normal/present, score 1 = abnormal/absent).
- fore- and hind-limb grip strength were recorded as the mean of three measurements (Series M4-10, Mark-10 Corporation, J.J. Bos, Gouda, The Netherlands).
- locomotor activity (recording period: 1-hour under normal laboratory light conditions, using a computerized monitoring system, Kinder Scientific LLC, Poway, USA). Total movements and ambulations were reported. Ambulations represent movements characterized by a relocation of the entire body position like walking, whereas total movements represent all movements made by the animals, including ambulations but also smaller or more fine movements like grooming,
weaving or movements of the head.

Pups:
Each litter was examined to determine the following, if practically possible:
- Mortality / Viability The numbers of live and dead pups were determined on Day 1 of lactation and daily thereafter. If possible, defects or cause of death were
evaluated.
- Clinical signs At least once daily, detailed clinical observations were made for all animals.
- Body weights Live pups were weighed on Days 1 and 4 of lactation.
- Sex was determined for all pups on Days 1 and 4 of lactation.

Sacrifice and pathology:

Parental animals (F0)

SACRIFICE: All surviving F0 adults were euthanized by carbon dioxide inhalation. Males were euthanized following completion of the mating period. Females that delivered were euthanized on lactation day 5 or within 24 hours of total litter loss; the numbers of former implantation sites and corpora lutea were recorded. Females that failed to deliver were euthanized on post mating day 25 (females with evidence of mating) or post-cohabitation day 25 (females with no evidence of mating).

GROSS PATHOLOGY: Yes
Uteri with no macroscopic evidence of implantation were opened and subsequently placed in 10 % ammonium sulfide solution for detection of early implantation loss. A gross necropsy was conducted on all animals including the female that was found dead during gestation; the numbers of corpora lutea and implantation sites were recorded and recognizable fetuses were examined externally for gross abnormalities. Necropsies included examination of the external surface, all orifices, the external surface of the brain, and the thoracic, abdominal, and pelvic cavities, including viscera.

ORGAN WEIGHTS: from F0 animals at the scheduled necropsies, the following organs were weighed: Adrenal glands, Ovaries with oviducts, Brain, Spleen, Epididymides, Testes, Heart, Thymus gland, Kidneys, Thyroids with parathyroids, Liver.

HISTOPATHOLOGY: Yes
At the time of necropsy, the following tissues and organs were placed in 10% neutral-buffered formalin: Adrenal glands (2), Lymph node (Axillary, Mesenteric, Mandibular), Aorta, Bone with marrow (sternebrae), Bone marrow smear ( not placed in formalin), Brain (Cerebrum level 1, Cerebrum level 2, Cerebellum with medulla/pons), Ovaries and oviducts (2), Pancreas, Peripheral nerve (sciatic), Pituitary gland, Coagulating glands, Prostate gland, Eyes with optic nerve (2) (in Davidson’s solution), Mandibular salivary glands (2), Gastrointestinal tract (Esophagus, Stomach, Duodenum, Jejunum, Ileum, Cecum, Colon, Rectum), Seminal vesicles (2), Skeletal muscle (rectus femoris), Skin with mammary gland, Spinal cord (cervical), Spleen, Testes with epididymides (2) (fixed in Bouin’s solution), Thymus gland, Thyroids [with parathyroids, if present (2)], Heart, Trachea, Kidneys (2), Urinary bladder, Liver (sections of 2 lobes), Uterus with cervix and vagina (in 10% ammonium sulfide solution), Lungs (including bronchi, fixed by inflation with fixative), All gross lesions.

Microscopic examination was performed on all tissues listed above from all animals in the control and 300 mg/kg/day groups. In addition, the liver, stomach, and all gross lesions from all animals at all dosage levels were examined microscopically. All organ and tissue samples, as defined under Histopathology (following section), were processed, embedded and cut at a thickness of 2-4 micrometers. These slides were stained with haematoxylin and eosin (Klinipath, Duiven, The Netherlands). The additional slides of the testes (to examine staging of spermatogenesis) were stained with PAS/haematoxylin (Klinipath, Duiven, The Netherlands). In addition,

Pups:
Pups surviving to planned termination were killed by decapitation on Day 5 of lactation. Pups found dead during the weekend were fixed in identified containers containing 70% ethanol (from Klinipath, Duiven, The Netherlands). All pups were sexed and descriptions of all external abnormalities were recorded. The stomach of pups not surviving to the scheduled necropsy date was examined for the presence of milk, if possible. If possible, defects or cause of death were evaluated.

Statistics:

The following statistical methods were used to analyze the data:
- If the variables could be assumed to follow a normal distribution, the Dunnett-test (Ref. 2; many-toone t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (Ref. 3; many-to-one rank test) was applied if the data could not be assumed to follow a normal distribution.
- The Fisher Exact-test (Ref. 4) was applied to frequency data.
- The Kruskal-Wallis nonparametric ANOVA test (Ref. 5) was applied to motor activity data to determine intergroup differences.

All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance. Group means were calculated for continuous data and medians were calculated for discrete data (scores) in the summary tables. Test statistics were calculated on the basis of exact values for means and pooled variances. Individual values, means and standard deviations may have been rounded off before printing. Therefore, two groups may display the same printed means for a given parameter, yet display different test statistics values.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

See belwo

Mortality:

mortality observed, treatment-related

Description (incidence):

See belwo

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not specified

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

See below

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

See below

Histopathological findings: neoplastic:

not specified

Details on results:

CLINICAL SIGNS AND MORTALITY:
There were two unscheduled deaths in this study: One control female (no. 46) had to be euthanized on Day 22 post-coitum. Before her death, hunched posture and piloerection were noted. She already had delivered 10 pups (1 dead and 9 alive), and an additional 2 pups (1 dead and 1 alive) were found in her uterus at necropsy. Other necropsy findings included many dark-red foci on the lungs and caecum, and watery-clear fluid in the thoracic cavity. The dark red focus/foci in the caecum correlated to a moderate necrotizing enteritis and was the vehicle alone, there was no relation to treatment with the test substance. One high dose female (no. 79) treated at 300 mg/kg/day was found dead on Day 0 post-coitum (i.e. after 16 days of treatment). When performing vaginal lavage, she was noted with labored respiration and piloerection. Shortly thereafter she was found dead. There were no indications for a bad condition of this female the days before her death. Gross findings at necropsy included irregular surface of the forestomach, many, dark-red foci on the thymus, and uterus containing fluid with its left horn containing reddish fluid. The likely cause of death was a gavage accident as evidenced by the microscopically marked (acute) ulceration in the trachea. Both these deaths were considered incidental and not related to treatment with the test substance.
There were no adverse effects on clinical appearance noted with treatment up to 300 mg/kg/day. Salivation seen after dosing at 30, 100 and 300 mg/kg/day was considered not toxicologically relevant, considering the nature and minor severity of the effect and its time of occurrence (i.e. after dosing). This sign was considered to be a physiological response related to taste and/or irritating properties of the test substance rather than a sign of systemic toxicity. One female at 30 mg/kg/day (no. 55) had swelling of the right axillary region during the last week of the study. At necropsy, a tan hard nodule was found which turned out to be an adenoma of the mammary gland. This rare benign neoplasm was considered to be a spontaneous finding with no relation to treatment. Rales were noted for two females at 100 mg/kg/day (nos. 62 and 65), and two males (nos. 33 and 37) and one female (no. 77) at 300 mg/kg/day over 1-7 days during the treatment period. In addition, female no. 62 had slight lethargy, hunched posture, piloerection and a lean appearance for 1-2 days, together with reduced water consumption (subjective appraisal, taken from study daybook) and slight body weight loss on Day 17 post-coitum. Other incidental observations included piloerection or swelling of the throat region noted for one female each at 300 mg/kg/day during 2 and 5 days, respectively. At the limited incidence observed and because these signs were transient, they were not considered to be adverse.

BODY WEIGHT AND WEIGHT GAIN:
No toxicologically or statistically significant changes in body weights and body weight gain were noted.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
NA

FOOD EFFICIENCY:
No toxicologically relevant changes in food consumption before or after allowance for body weight were noted. For males at 300 mg/kg/day, food consumption (absolute and relative) was slightly, but not statistically significantly, lower during the first week of treatment (Days 1-8 pre-mating). No toxicological significance was attributed to this as changes compared to the control group were only slight and occurred transiently.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study):
NA

OPHTHALMOSCOPIC EXAMINATION:
NA

HAEMATOLOGY:
There were no differences noted in haematological parameters between control and treated rats that were considered to be related to treatment with TMPTA.
For males at 300 mg/kg/day, the percentage of reticulocytes was statistically significantly higher compared to the concurrent control group. This finding was not considered to be toxicologically relevant as all individual values remained within the normal range of biological variation. At the individual level, a relatively high reticulocyte count with a concurrent lower red blood cell count and a high value for red blood cell distribution width (RDW) was found for one control female (no. 48). This finding correlated with a relatively high spleen weight (absolute and relative to body weight) and markedly increased extramedullary hematopoiesis in the spleen at the microscopic level. Since this was a female in the control group, a relation to treatment with the test substance could be excluded.

CLINICAL CHEMISTRY:
No toxicologically relevant changes occurred in clinical biochemistry parameters of treated rats. The following statistically significant changes in clinical biochemistry parameters were noted for treated rats as compared to controls: decreased potassium at 30 mg/kg/day (males), decreased calcium at 30 and 100 mg/kg/day (males), and increased calcium at 300 mg/kg/day (females). No toxicologically relevance was attached to these findings as values remained within the normal range of biological variation, the differences from the control group were not accompanied by relevant changes in other clinical biochemistry parameters and/or corroborative histopathological changes, and/or a dose-related response was absent. At the individual level, relatively high concentrations of urea, bile acids and/or inorganic phosphate were found for two females at 300 mg/kg/day (nos. 72 and 74). In the absence of corroborative histopathological findings, it was not considered to be toxicologically relevant.

URINALYSIS:
NA

NEUROBEHAVIOUR:
Hearing ability, pupillary reflex, static righting reflex and grip strength were not affected by treatment. The slightly lower grip strength of the fore- and hindlegs recorded for females at 300 mg/kg/day was not considered to be toxicologically relevant as changes were relative slight and values remained within the normal range of biological variation. The variation in motor activity did not indicate a relation with treatment. All groups showed a similar habituation profile with high activity in the first interval that decreased over the duration of the test period.

ORGAN WEIGHTS:
No toxicologically relevant changes were noted in organ weights and organ to body weight ratios. Statistically significant changes comprised lower absolute adrenal weight in males at 30 mg/kg/day, higher relative heart weight in males at 300 mg/kg/day, and higher absolute and relative thymus weight in females at 100 mg/kg/day, when compared to control. These changes were considered to be of no toxicological relevance as they remained within the range considered normal for rats of this age and strain and/or occurred in the absence of a treatment-related distribution. The relatively high ovaries weight for one female at 300 mg/kg/day (no. 75) was caused by a wateryclear cyst (10x15 mm) on her left ovary. This cyst was considered to be a chance finding and not treatment-related. It is seen incidentally in female rats of this age and strain.

GROSS PATHOLOGY:
Test item-related macroscopic findings were present in the non-glandular part of the stomach (i.e. forestomach) in the form of irregular surface (correlating microscopic observation: squamous cell hyperplasia forestomach) in 5/10 males treated at 100 mg/kg/day, and 7/10 males and 7/10 females (including the female that died spontaneously) at 300 mg/kg/day. No macroscopic findings were noted in the forestomach of males and females treated at 30 mg/kg/day, and in females treated at 100 mg/kg/day. Incidental findings among control and treated animals were within the background range of findings that are encountered among rats of this age and strain, and did not show a dose-related trend. These necropsy findings were therefore considered to be unrelated to treatment.


HISTOPATHOLOGY: NON-NEOPLASTIC:
Test item-related microscopic findings present in the non-glandular part of the stomach (i.e. forestomach) included:
- Inflammation of the forestomach was present in males and females treated at 100 and 300 mg/kg/day up to a moderate degree.
- Hyperplasia squamous cell of the forestomach was present in males and females treated at 100 and 300 mg/kg/day up to a marked degree.
- Ulceration of the forestomach was present in a single female treated at 300 mg/kg/day at a slight degree.
These microscopic changes (inflammation, squamous cell hyperplasia and/or ulceration) correlated to the macroscopic observation of irregular surface in the forestomach. There were no other test substance-related histologic changes. The remainder of the recorded microscopic findings were within the range of background pathology encountered in rats of this age and strain. There was no test substance-related alteration in the prevalence, severity, or histologic
character of those incidental tissue alterations.

HISTOPATHOLOGY: NEOPLASTIC (if applicable):
NA

HISTORICAL CONTROL DATA (if applicable):
Available

OTHER FINDINGS:
NA

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Critical effects observed:

not specified

Chemical analyses:

Analysis of dose preparations showed that no test substance was detected in the Group 1 formulations (control group). The concentrations analysed in the formulations of Groups 2, 3 and 4 prepared for use on 04 and 31 March 2015 were in agreement with the target concentrations (i.e. mean accuracies between 90% and 110%). The formulations of Group 2 and Group 4 prepared for use on 04 and 31 March 2015 were homogeneous (i.e. coefficient of variation ≤ 10%). Formulations at the entire range were stable when stored at room temperature protected from light for at least 5 hours (i.e. relative difference ≤ 10%). The long term storage samples were stable at ≤-70°C for at least 34 days. It should be noted that the tested storage period was slightly shorter than the maximum storage period in this study which was 37 days for the formulation samples taken on treatment Day 28. Data from the accuracy measurement of these samples showed no degradation of the test substance in formulation after storage in the freezer, thereby supporting stability over the longer period. Overall, formulation analysis showed that the formulations were prepared accurately and homogenously, and were stable when stored at room temperature protected from light for at least 5 hours.

Conclusions:

The repeated dose toxicity (28-day) of TMPTA was evaluated in a combined 28-day repeated dose toxicity study with the reproduction/developmental toxicity screening test in accordance with OECD 422. TMPTA was administered by daily oral gavage to male and female Wistar Han rats at dose levels of 30, 100 and 300 mg/kg/day. A NOAEL of 30 mg/kg bw/day for local toxicity and a NOAEL of 300 mg/kg bw/day for systemic toxicity could be derived for parental toxicity (F0). No higher doses could be tested due to test substance related local toxicity on the non-glandular part of the stomach (i.e. the forestomach) at doses of 100 mg/kg/day and higher.

Executive summary:

The repeated dose toxicity (28-day) of TMPTA was evaluated in a combined 28-day repeated dose toxicity study with the reproduction/developmental toxicity screening test in accordance with OECD 422. TMPTA was administered by daily oral gavage to male and female Wistar Han rats at dose levels of 30, 100 and 300 mg/kg/day. Males were exposed for 2 weeks prior to mating, during mating, and up to termination (for 29 days). The females were exposed for 2 weeks prior to mating, during mating, during gestation, and at least 4 days of lactation (for 41-55 days).

Treatment with TMPTA at dose levels of 30, 100 and 300 mg/kg/day revealed parental toxicity at 100 and 300 mg/kg/day (both sexes). There were only adverse local morphologic alterations in the non-glandular part of the stomach, the forestomach, which represented a local irritating effect of the test substance rather than a systemic effect. No treatment-related toxicologically significant changes were noted in any of the remaining parental parameters investigated in this study (i.e. clinical appearance, functional observations, body weight, food consumption, clinical laboratory investigations and organ weights).

Based on these results, a NOAEL of 30 mg/kg bw/day for local toxicity and a NOAEL of 300 mg/kg bw/day for systemic toxicity could be derived for parental toxicity (F0). No higher doses could be tested due to test substance related local toxicity on the non-glandular part of the stomach (i.e. the forestomach) at doses of 100 mg/kg/day and higher.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

High quality study perforned according to OECD 422.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to GLP, following NTP standard protocol

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

not specified

Principles of method if other than guideline:

NA

GLP compliance:

yes

Limit test:

no

Species:

other: Mice and rats

Strain:

other:

Sex:

male/female

Type of coverage:

other: Dermal

Vehicle:

acetone

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Dose formulations were analyzed approximately every 3 months. All formulations analyzed (35 for rats, 37 for mice) were within 10% of the target concentration. Samples taken from the animal room were generally high due to evaporation of acetone during dosing.

Duration of treatment / exposure:

104 to 105 weeks (rats); 105 to 106 weeks (mice) interim evaluations performed after 2, 13, 52 weeks

Frequency of treatment:

5 times per week

Remarks:

Doses / Concentrations:
0.3, 1.0, 3.0mg/kg
Basis:

No. of animals per sex per dose:

65

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: In the 2-week and 3-month dermal toxicity studies (NTP, 2005), the skin was the only target organ identified for trimethylolpropane triacrylate. Therefore, the dose levels for the trimethylolpropane triacrylate 2-year studies were selected based on the severity of the skin lesions. Doses were selected to avoid significant skin irritation, and to preclude adverse effects on survival and growth of animals. Based upon the histologic data from the 3-month studies, 3 mg/kg was considered the likely maximum tolerated dose and an acceptable high dose for the 2-year toxicity and carcinogenicity studies. Thus, the doses selected for both rats and mice were 0, 0.3, 1.0, and 3.0 mg trimethylolpropane triacrylate /kg body weight in acetone.

Positive control:

None included in the study design

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: every 4 weeks

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: at 2, 13, and 52 weeks, skin from the site of application was collected from interim evaluation animals (5 per sex and dose), fixed in formalin, and examined microscopically.

BODY WEIGHT: Yes
- Time schedule for examinations: weekly for the first 13 weeks, every 4 weeks thereafter

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: No

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes. The following organs were fixed in 10% formalin, embedded in paraffin and stained with hematoxylin and eosin:
In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone, brain, clitoral gland, esophagus, eyes, gallbladder (mice), Harderian gland, heart and aorta, large intestine (cecum, colon, rectum), small intestine (duodenum, jejunum, ileum), kidney, liver, lung and mainstem bronchi,lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin (site of application and control site), spleen, stomach (forestomach and glandular), testis with epididymis and seminal vesicle, thymus, thyroid gland, trachea, urinary bladder, and uterus.

Other examinations:

No

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

See below

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Details on results:

No differences in body weights or survival of dosed animals compared to the vehicle controls. There were no clinical findings of toxicity related to TMPTA administration.

TMPTA increased the incidences of epidermal hyperplasia, characteristic of tumor promotion, at the site of application in a dose-dependent manner in rats and mice at all the time points examined. Dose dependent, significant increases in the incidences of hyperkeratosis at the site of application were observed in male and female rats. Both hyperplasia and hyperkeratosis are characteristics of chronic irritant contact dermatitis. These results are consistent with the dermal irritant effect of TMPTA reported. Skin irritation is an inflammatory response affecting all stages of carcinogenesis.

In conclusion, dermal application of TMPTA for 2 years resulted in increased incidences of nonneoplastic lesions in the skin (site of application) of male and female rats and mice. No systemic toxicity was observed in rats and mice.

Key result

Dose descriptor:

LOAEL

Effect level:

0.3 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Local effects

Sex:

male/female

Basis for effect level:

other: The LOAEL was identified for female rats. (NOAEL of 0.3 mg/kg bw/d could be identified for male rats and male/female mice)

Critical effects observed:

not specified

Conclusions:

The chronic toxicity of TMPTA dermally applied to mice and rats was examined in an NTP study (2012). Groups of 65 male and 65 female mice and rats received dermal applications of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body weight in acetone, 5 days per week for 105 to 106 weeks (core study). At 2 weeks, 13 weeks, and 12 months, five animals per sex per dose group were randomly selected for histological examination of skin tissue. Survival and mean body weights of all dosed groups were similar to those of the vehicle control groups. Local effects on skin was observed at 0.3 mg/kg/d in rats , whereas 0.3 mg/kg/d in mice was found as a NOAEL.

Executive summary:

The chronic toxicity of TMPTA dermally applied to mice and rats was examined in an NTP study (2012). Groups of 65 male and 65 female mice and rats received dermal applications of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body weight in acetone, 5 days per week for 105 to 106 weeks (core study). At 2 weeks, 13 weeks, and 12 months, five animals per sex per dose group were randomly selected for histological examination of skin tissue. Survival and mean body weights of all dosed groups were similar to those of the vehicle control groups. There were no clinical findings of toxicity related to TMPTA administration.

TMPTA increased the incidences of epidermal hyperplasia, characteristic of tumor promotion, at the site of application in a dose-dependent manner in rats and mice at all the time points examined. Dose dependent, significant increases in the incidences of hyperkeratosis at the site of application were observed in male and female rats. Both hyperplasia and hyperkeratosis are characteristics of chronic irritant contact dermatitis. These results are consistent with the dermal irritant effect of TMPTA reported. Skin irritation is an inflammatory response affecting all stages of carcinogenesis. In conclusion, dermal application of TMPTA for 2 years resulted in increased incidences of nonneoplastic lesions in the skin (site of application) of male and female rats and mice. No systemic toxicity was observed in rats and mice.

In conclusion, local effects on skin was observed at 0.3 mg/kg/d in rats (LOAEL) , whereas 0.3 mg/kg/d in mice was found as a NOAEL.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

3 mg/kg bw/day

Study duration:

subchronic

Species:

other: Rats and Mice

Quality of whole database:

In a NTP-study using rats and mice dermal application during 2 years caused no systemic effects at highest dose level of 3 mg/kg/d.

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to GLP, following NTP standard protocol

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

not specified

Principles of method if other than guideline:

NA

GLP compliance:

yes

Limit test:

no

Species:

other: Mice and rats

Strain:

other:

Sex:

male/female

Type of coverage:

other: Dermal

Vehicle:

acetone

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Dose formulations were analyzed approximately every 3 months. All formulations analyzed (35 for rats, 37 for mice) were within 10% of the target concentration. Samples taken from the animal room were generally high due to evaporation of acetone during dosing.

Duration of treatment / exposure:

104 to 105 weeks (rats); 105 to 106 weeks (mice) interim evaluations performed after 2, 13, 52 weeks

Frequency of treatment:

5 times per week

Remarks:

Doses / Concentrations:
0.3, 1.0, 3.0mg/kg
Basis:

No. of animals per sex per dose:

65

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: In the 2-week and 3-month dermal toxicity studies (NTP, 2005), the skin was the only target organ identified for trimethylolpropane triacrylate. Therefore, the dose levels for the trimethylolpropane triacrylate 2-year studies were selected based on the severity of the skin lesions. Doses were selected to avoid significant skin irritation, and to preclude adverse effects on survival and growth of animals. Based upon the histologic data from the 3-month studies, 3 mg/kg was considered the likely maximum tolerated dose and an acceptable high dose for the 2-year toxicity and carcinogenicity studies. Thus, the doses selected for both rats and mice were 0, 0.3, 1.0, and 3.0 mg trimethylolpropane triacrylate /kg body weight in acetone.

Positive control:

None included in the study design

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: every 4 weeks

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: at 2, 13, and 52 weeks, skin from the site of application was collected from interim evaluation animals (5 per sex and dose), fixed in formalin, and examined microscopically.

BODY WEIGHT: Yes
- Time schedule for examinations: weekly for the first 13 weeks, every 4 weeks thereafter

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: No

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes. The following organs were fixed in 10% formalin, embedded in paraffin and stained with hematoxylin and eosin:
In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone, brain, clitoral gland, esophagus, eyes, gallbladder (mice), Harderian gland, heart and aorta, large intestine (cecum, colon, rectum), small intestine (duodenum, jejunum, ileum), kidney, liver, lung and mainstem bronchi,lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin (site of application and control site), spleen, stomach (forestomach and glandular), testis with epididymis and seminal vesicle, thymus, thyroid gland, trachea, urinary bladder, and uterus.

Other examinations:

No

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

See below

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Details on results:

No differences in body weights or survival of dosed animals compared to the vehicle controls. There were no clinical findings of toxicity related to TMPTA administration.

TMPTA increased the incidences of epidermal hyperplasia, characteristic of tumor promotion, at the site of application in a dose-dependent manner in rats and mice at all the time points examined. Dose dependent, significant increases in the incidences of hyperkeratosis at the site of application were observed in male and female rats. Both hyperplasia and hyperkeratosis are characteristics of chronic irritant contact dermatitis. These results are consistent with the dermal irritant effect of TMPTA reported. Skin irritation is an inflammatory response affecting all stages of carcinogenesis.

In conclusion, dermal application of TMPTA for 2 years resulted in increased incidences of nonneoplastic lesions in the skin (site of application) of male and female rats and mice. No systemic toxicity was observed in rats and mice.

Key result

Dose descriptor:

LOAEL

Effect level:

0.3 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Local effects

Sex:

male/female

Basis for effect level:

other: The LOAEL was identified for female rats. (NOAEL of 0.3 mg/kg bw/d could be identified for male rats and male/female mice)

Critical effects observed:

not specified

Conclusions:

The chronic toxicity of TMPTA dermally applied to mice and rats was examined in an NTP study (2012). Groups of 65 male and 65 female mice and rats received dermal applications of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body weight in acetone, 5 days per week for 105 to 106 weeks (core study). At 2 weeks, 13 weeks, and 12 months, five animals per sex per dose group were randomly selected for histological examination of skin tissue. Survival and mean body weights of all dosed groups were similar to those of the vehicle control groups. Local effects on skin was observed at 0.3 mg/kg/d in rats , whereas 0.3 mg/kg/d in mice was found as a NOAEL.

Executive summary:

The chronic toxicity of TMPTA dermally applied to mice and rats was examined in an NTP study (2012). Groups of 65 male and 65 female mice and rats received dermal applications of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body weight in acetone, 5 days per week for 105 to 106 weeks (core study). At 2 weeks, 13 weeks, and 12 months, five animals per sex per dose group were randomly selected for histological examination of skin tissue. Survival and mean body weights of all dosed groups were similar to those of the vehicle control groups. There were no clinical findings of toxicity related to TMPTA administration.

TMPTA increased the incidences of epidermal hyperplasia, characteristic of tumor promotion, at the site of application in a dose-dependent manner in rats and mice at all the time points examined. Dose dependent, significant increases in the incidences of hyperkeratosis at the site of application were observed in male and female rats. Both hyperplasia and hyperkeratosis are characteristics of chronic irritant contact dermatitis. These results are consistent with the dermal irritant effect of TMPTA reported. Skin irritation is an inflammatory response affecting all stages of carcinogenesis. In conclusion, dermal application of TMPTA for 2 years resulted in increased incidences of nonneoplastic lesions in the skin (site of application) of male and female rats and mice. No systemic toxicity was observed in rats and mice.

In conclusion, local effects on skin was observed at 0.3 mg/kg/d in rats (LOAEL) , whereas 0.3 mg/kg/d in mice was found as a NOAEL.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LOAEL

0.3

Study duration:

chronic

Species:

rat

Quality of whole database:

High quality long-term NTP study causing dermal irritation in rats at lowest dose level tested 0.3 mg/kg/d.

Additional information

Oral studies:

OECD 422: TMPTA was administered by daily oral gavage to male and female Wistar Han rats at dose levels of 30, 100 and 300 mg/kg/day. Males were exposed for 2 weeks prior to mating, during mating, and up to termination (for 29 days). The females were exposed for 2 weeks prior to mating, during mating, during gestation, and at least 4 days of lactation (for 41-55 days).

Treatment with TMPTA at dose levels of 30, 100 and 300 mg/kg/day revealed parental toxicity at 100 and 300 mg/kg/day (both sexes). There were only adverse local morphologic alterations in the non-glandular part of the stomach, the forestomach, which represented a local irritating effect of the test substance rather than a systemic effect. No treatment-related toxicologically significant changes were noted in any of the remaining parental parameters investigated in this study (i.e. clinical appearance, functional observations, body weight, food consumption, clinical laboratory investigations and organ weights).

Based on these results, a NOAEL of 30 mg/kg bw/day for local toxicity and a NOAEL of 300 mg/kg bw/day for systemic toxicity could be derived for parental toxicity (F0). No higher doses could be tested due to test substance related local toxicity on the non-glandular part of the stomach (i.e. the forestomach) at doses of 100 mg/kg/day and higher.

The repeated dose toxicity of 1,3,5-TRIAZINE-2,4,6(1H,3H,5H)-TRIONE,1,3,5-TRIS(2HYDROXYETHYL) (S3) was evaluated in a combined repeated dose toxicity study with the reproduction/developmental toxicity screening test in accordance with OECD 422. Twelve animals per dose group received oral gavage with 0, 30, 100, 300, 1,000 mg/kg bw/day for 40-46 days (females) or 49 days (males). No toxicological effect were observed neither were any pathological or histopathological changes were observed. However, extramedullary hematopoiesis in the liver was noted in two female animals (2/12 animals) at 1,000 mg/kg bw/day. Although the author showed this change was the substance-related one in the original paper, it was considered to be no adverse effect because the change was not statistically significant from control and no other changes were observed at this dose level.

 

Dermal studies:

The chronic toxicity of TMPTA (S2) dermally applied to mice and rats was examined in an NTP study (2012). Groups of 65 male and 65 female mice and rats received dermal applications of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body weight in acetone, 5 days per week for 105 to 106 weeks (core study). At 2 weeks, 13 weeks, and 12 months, five animals per sex per dose group were randomly selected for histological examination of skin tissue. Survival and mean body weights of all dosed groups were similar to those of the vehicle control groups. There were no clinical findings of toxicity related to TMPTA administration. TMPTA increased the incidences of epidermal hyperplasia, characteristic of tumor promotion, at the site of application in a dose-dependent manner in rats and mice at all the time points examined. Dose dependent, significant increases in the incidences of hyperkeratosis at the site of application were observed in male and female rats. Both hyperplasia and hyperkeratosis are characteristics of chronic irritant contact dermatitis. These results are consistent with the dermal irritant effect of TMPTA reported. Skin irritation is an inflammatory response affecting all stages of carcinogenesis. In conclusion, dermal application of TMPTA for 2 years resulted in increased incidences of nonneoplastic lesions in the skin (site of application) of male and female rats and mice. No systemic toxicity was observed in rats and mice. Local effects on skin was observed at 0.3 mg/kg/d in rats (LOAEL), whereas 0.3 mg/kg/d in mice was found as a NOAEL.

Justification for classification or non-classification

Data from read-across substance TMPTA (justification for read-across attached in section 13)

Oral toxicity:

No systemic toxicity was observed for the read-across substance TMPTA in an OECD 422 study at the highest dose level of 300 mg/kg/d in rats during 28 days repeated oral administration.

Dermal toxicity:

No systemic toxicity was observed in rats and mice for the read-across substance TMPTA. Local effects on skin was observed at 0.3 mg/kg/d in rats (LOAEL) , whereas 0.3 mg/kg/d in mice was found as a NOAEL.

Classification for specific target organ toxicity or danger at repeated or prolonged exposure:

As for the read-across subtance TMPTA no classification in relation to STOT RE should apply for

Reaction mass og THEICTA and THEICDA, due to lack of systemic toxicity observed at 300 mg/kg bw/d for the read-across substance.