2-Propenoic acid, reaction products with pentaerythritol

Endpoint summary

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

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:

From January to September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to standard guidelines in compliance with GLP.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

During the acclimation period, the animals were observed twice daily for mortality and general changes in appearance and behavior instead of once. The cage-board was changed at least 3 times per week . Body weights recorded on gestation day 14 were used t

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

other: Crl:CD(SD)]

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, NC, USA
- Age at study initiation: ca. 63 d
- Housing: stainless steel wire mesh cages suspended above cage board
- Diet (e.g. ad libitum): PMI Nutrition International, LLC Certified Rodent LabDiet® 5002
- Water (e.g. ad libitum): yes
- Acclimation period: 17 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.8 - 22.7°C
- Humidity (%): 38.2 - 45.1%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 29 January 2010 To: 19 May 2010

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

VEHICLE
- Justification for use and choice of vehicle (if other than water): corn oil
- Concentration in vehicle: 0, 5, 15 or 40 mg/ml
- Amount of vehicle (if gavage): 5ml/kg bw
- Lot/batch no. (if required): YF0793, YR1134, and YJ0917

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Fifteen-day room temperature resuspension homogeneity and stability of the test substance formulated in the vehicle at concentrations of 10 and 200 mg/mL were established in a previous study (Stump, Draft, WIL-738003). Therefore, resuspension homogeneity and stability were not assessed for the 15 and 40 mg/mL formulations prepared for the current study.

Prior to the initiation of dose administration, quadruplicate samples for homogeneity and concentration determination were collected from the top, middle, and bottom strata of the 5 mg/mL non-dosing formulation. However, because the analytical results of the initial samples as well as the back-up samples did not meet the WIL Research Laboratories, LLC’s SOP requirements, a new 5 mg/mL non-dosing formulation was prepared. Quadruplicate samples for homogeneity and concentration determination were collected from the top, middle, and bottom strata of the new 5 mg/mL non-dosing formulation. In addition, quadruplicate samples for resuspension homogeneity and stability determinations were collected from aliquots prepared from this same non-dosing formulation following room temperature storage for 5 and 13 days; the aliquots were stirred for at least 60 minutes prior to sampling. Quadruplicate samples for homogeneity and concentration analyses were collected from the top, middle, and bottom of the test substance formulations prepared for the first week of dose administration; samples were also collected from the middle stratum of the vehicle control formulation. Additionally, quadruplicate samples for concentration analysis were collected from the middle stratum of each dosing formulation and vehicle control formulation prepared for the remainder of the study. One set of duplicate samples from each collection was subjected to the appropriate analyses. The remaining set of duplicate samples was stored frozen (approximately -70°C ± 5°C) as back-up. All analyses were conducted by the Analytical Chemistry Department at WIL Research Laboratories, LLC using a validated high performance liquid chromatography method with ultraviolet absorbance detection.

Duration of treatment / exposure:

The males were dosed once daily during study Days 0-27 (14 days prior to pairing through 1 day prior to scheduled euthanasia) for a total of 28 doses. The females were dosed once daily during study Days 0 through the day prior to euthanasia (14 days prior to pairing through lactation day 4) for a total of 40-47 doses. Females that failed to deliver were dosed through the day prior to euthanasia (post-mating day 25) for a total of 41 doses.

Frequency of treatment:

Daily

Remarks:

Doses / Concentrations:
0, 25, 75 or 200 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

12 males and 12 females

Control animals:

yes

Details on study design:

- Dose selection rationale: Dosage levels were selected based on the results of previous studies and were provided by the Sponsor after consultation with the Study Director. In a previous 14-day toxicity study in Crl:CD(SD) rats (Stump, Draft, WIL-738003), the maximum tolerated dose was exceeded at 1000 mg/kg/day. At 300 mg/kg/day, lower mean body weight gains, reduced food consumption, adverse clinical signs, and/or changes in mean organ weights were noted for males and females. Based on these results, dosage levels of 25, 75, and 200 mg/kg/day were selected to be evaluated in the current study.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: All rats were observed twice daily, once in the morning and once in the afternoon, for moribundity and mortality. A detailed physical examination was conducted weekly on each animal beginning approximately 1 week prior to the initiation of dose administration, including on the day of necropsy.

BODY WEIGHT: Yes
- Time schedule for examinations: Individual male body weights were recorded beginning approximately 1 week prior to the initiation of dose administration, on the first day of dose administration and weekly thereafter until the day prior to scheduled euthanasia. Individual female body weights were recorded beginning approximately 1 week prior to the initiation of dose administration, on the first day of dose administration and weekly thereafter until the day evidence of copulation was observed.

FOOD CONSUMPTION:
- Individual food consumption was recorded on the corresponding weekly body weight days until pairing. Food intake was not recorded during the mating period. Once evidence of mating was observed, female food consumption was recorded on gestation days 0, 4, 7, 11, 14, 17, and 20 and on lactation days 1 and 4. Following mating, food consumption for the female with no evidence of mating was measured on a weekly basis until parturition. When food consumption could not be determined for an animal during a given interval (due to an unscheduled death, as females enter gestation/lactation, weighing error, food spillage, obvious erroneous value, etc.), group mean values were calculated for that interval using the available data.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at necropsy (Study Day 28 for males and Lactation Day 5 for females)
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes
- How many animals: 6 animals/sex/group

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at necropsy (Study Day 28 for males and Lactation Day 5 for females)
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes
- How many animals: 6 animals/sex/group

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- FOB assessments were recorded for 6 animals/sex/group prior to dose administration and fasting for clinical pathology sampling on study day 27 (males) and lactation day 4 (females).
- Locomotor activity counts were recorded for 6 animals/sex/group prior to dose administration on study day 27 (males) and on lactation day 4 (females); the same animals evaluated for FOB were selected for locomotor activity assessment.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

F0 GENERATION

CLINICAL OBSERVATIONS AND SURVIVAL

Test substance-related mortality and/or moribundity were noted in the 75 mg/kg bw/day group (2 males) and the 200 mg/kg bw/day group (2 males and 3 females). Clinical findings noted for the majority of the animals that did not survive to the scheduled necropsy included gasping, rales, limbs cool to touch, cool body, labored respiration, mucoid feces, salivation, and red, yellow, and clear material primarily around the mouth; single animals were also noted with wiping mouth in the bedding, splayed limbs, and tonic convulsions at the post-dosing observations. Although the cause of death of death/moribundity of these animals was not determined upon microscopic examination, all animals were noted with lesions in the stomach and lymphoid depletion or lymphoid necrosis in the thymus and generally in the spleen. All other animals survived to the scheduled necropsies.

For animals that survived to the scheduled necropsy, salivation-related findings (salivation prior to or at time of dosing and clear material around the mouth and nose) were noted for the majority of the animals in the 75 and 200 mg/kg bw/day groups primarily at the time of dose administration or approximately 1 h following dose administration; these findings were also occasionally noted for the 25 mg/kg bw/day group animals and were likely signs of taste aversion related to the irritating properties of the compound that resulted in stomach findings and were not considered adverse. Furthermore, the majority of the females in the 25, 75, and 200 mg/kg bw/day groups were noted to be wiping their mouth in the bedding following dose administration due to the irritative nature of the test substance formulations. Incidences of yellow and red material primarily around the mouth were also noted sporadically across all dosage levels during the treatment period, and incidences of rales were noted for a few animals primarily in the 75 and 200 mg/kg bw/day groups at the time of dose administration and/or approximately 1 h following dose administration. These findings were likely related to aspiration of the test substance formulations.
Other clinical findings noted at the daily examinations, at the time of dose administration, or approximately 1 h following dose administration, including hair loss on various body surfaces, occurred infrequently and/or at similar frequencies in the control group, and were not attributed to test substance administration.

BODY WEIGHTS

Test substance-related lower mean body weight gains were noted in the 200 mg/kg bw/day group throughout the treatment period (study Day 0-27); the difference from the control group achieved significance (p<0.01) during study Day 7-13. As a result, mean body weight gains in this group were significantly (p<0.01) lower when the overall pre-mating period (study Day 0-13) and treatment period (study Day 0-27) were evaluated and mean body weights were 7.1% to 8.8% lower during study Day 13-27 compared to the control group; differences in mean body weights were significant (p<0.05) on study Day 21 and 27.
In the 75 mg/kg bw/day group males, slightly (not statistically significant) lower mean body weight gains were noted during study Day 0-21. During study Day 21-27, mean body weight gain in this group was markedly (not statistically significant) lower primarily due to 2 animals (male) noted with body weight losses of 29 g to 34 g during this interval. However, the differences in mean body weight gains were not of a sufficient magnitude to result in statistically significant differences when the overall pre-mating (study Day 0-13) and treatment (study Day 0-27) periods were evaluated and mean body weights in this group were similar to the control group values throughout the treatment period.

Mean male body weights and body weight gains in the 25 mg/kg bw/day group were similar to the control group throughout the treatment period. Differences from the control group were slight and not statistically significant.

FEMALES
Mean female body weights and body weight gains in the 25, 75, and 200 mg/kg bw/day groups were similar to the control group during the pre-mating period (study Day 0-13). Differences from the control group were slight and not statistically significant.

GESTATION
Mean body weights and body weight gains in the 25, 75, and 200 mg/kg bw/day groups were unaffected by test substance administration during gestation. A significantly (p<0.05) lower mean body weight gain was noted in the 200 mg/kg bw/day group during gestation Day 7-11 compared to the control group. However, this difference was transient and therefore, not attributed to test substance administration. In the 75 mg/kg bw/day group, mean body weight gain was significantly (p<0.05) lower when the overall gestation period (gestation Day 0-20) was evaluated. In the absence of a dose-related trend, this difference was not attributed to test substance administration. All other differences in mean body weight gains during gestation were slight and not statistically significant when the test substance-treated groups were compared to the control group.

LACTATION
Mean body weights and body weight gains in the 25, 75, and 200 mg/kg bw/day groups were similar to the control group during lactation Day 1-4. Differences from the control group were slight and not statistically significant.

FOOD CONSUMPTION

MALES
Mean male food consumption, evaluated as g/animal/day and g/kg/day, in the 200 mg/kg bw/day group, was slightly reduced during the pre-mating period (study Day 0-13). Although differences from the control group did not achieve statistical significance, the lower mean food consumption in this group corresponded to reductions in mean body weight gains during this period.
Mean male food consumption in the 25 and 75 mg/kg bw/day groups was similar to the control group during the pre-mating period (study Day 0-13). Differences from the control group were slight and not statistically significant.

FEMALES
Mean female food consumption in the 25, 75, and 200 mg/kg bw/day groups was similar to the control group throughout the pre-mating period (study Day 0-13).

GESTATION
Mean food consumption in the 25, 75, and 200 mg/kg bw/day groups was unaffected by test substance administration during gestation. Significantly (p<0.05) lower mean food consumption was noted in the 200 mg/kg bw/day group during gestation Day 14-17 (g/animal/day and g/kg/day) and when the overall gestation period (gestation Day 0-20; g/kg/day only) was evaluated.

LACTATION
Mean food consumption in the 25, 75, and 200 mg/kg bw/day groups was unaffected by test substance administration during lactation Day 1-4. Differences from the control group were slight and not statistically significant.

FUNCTIONAL OBSERVATIONAL BATTERY (FOB)

HOME CAGE OBSERVATIONS
Home cage parameters were unaffected by test substance administration at all dosage levels. There were no statistically significant differences for the test substance-treated groups when compared to the control group on study Day 27 (males) or lactation Day 4 (females).

HANDLING OBSERVATIONS
Handling parameters were unaffected by test substance administration at all dosage levels. There were no statistically significant differences for the test substance-treated groups when compared to the control group on study Day 27 (males) or lactation Day 4 (females).

OPEN FIELD OBSERVATIONS
Open field parameters were unaffected by test substance administration at all dosage levels. A significant (p<0.01) increase in mean defecation counts was noted in the 25 mg/kg bw/day group females (1.7 counts) compared to the control group (0.0 counts) on lactation Day 4. However, in the absence of a dose-related response, this difference was not attributed to test substance administration. There were no other statistically significant differences for the test substance-treated groups when compared to the control group on study Day 27 (males) or lactation Day 4 (females).

SENSORY OBSERVATIONS
Sensory parameters were unaffected by test substance administration at all dosage levels. There were no statistically significant differences for the test substance-treated groups when compared to the control group during on study Day 27 (males) or lactation Day 4 (females).

NEUROMUSCULAR OBSERVATIONS
Neuromuscular parameters were unaffected by test substance administration at all dosage levels. There were no statistically significant differences for the test substance-treated groups when compared to the control group on study Day 27 (males) or lactation Day 4 (females).

PHYSIOLOGICAL OBSERVATIONS
A lower (10.3%) mean body weight was noted for the 200 mg/kg bw/day group males compared to the control group at the physiological observations on study Day 27. Although this difference did not achieve statistical significance, the lower mean body weight corresponded to the lower weekly mean body weights recorded for this group during the treatment period. No other differences in physiological parameters were attributed to test substance administration at any dosage level. There were no statistically significant differences for the test substance-treated groups when compared to the control group on study Day 27 (males) or lactation Day 4 (females).

LOCOMOTOR ACTIVITY
Locomotor activity patterns (total activity as well as ambulatory activity counts) were unaffected by test substance administration at all dosage levels when evaluated on study Day 27 (males) and lactation Day 4 (females). Values obtained from the 6 subintervals evaluated (0-10, 11-20, 21-30, 31-40, 41-50 and 51-60 minutes) and the overall 60-minute test session values were comparable to the concurrent control values and the WIL historical control data (Version 1.3). Differences from the control group were slight, not statistically significant when analyzed by a repeated measures analysis, within the WIL historical control data ranges, and/or did not occur in a dose-related manner. No remarkable shifts in the pattern of habituation occurred in any of the test substance-treated groups.

CLINICAL PATHOLOGY
Higher mean absolute neutrophil counts were noted in the 75 and 200 mg/kg bw/day group males (approximately 149% and 185%, respectively) and females (approximately 46% and 118%, respectively). The difference for the 200 mg/kg bw/day group females achieved significance (p<0.01). These higher neutrophil counts were consistent with the test substance-related ulcerations and associated inflammation that was present in the non-glandular stomach.
There were no other test substance-related effects on hematology or coagulation parameters. Significant (p<0.05 or p<0.01) differences from the control group included lower mean red blood cell counts and hemoglobin values in the 25 and 200 mg/kg bw/day group males and a lower hematocrit in the 25 mg/kg bw/day group males. These group mean differences were not considered to be test substance-related because the values did not show a dose-related response. Mean absolute reticulocyte count for the 200 mg/kg bw/day group males was higher (not statistically significant) than the 0 mg/kg bw/day group males but the value was within the range of historical control data (version 3.1). Significant (p<0.05 or p<0.01) findings that involved percentage reticulocyte or leukocyte differential counts were not itemized above and were not considered toxicologically important because absolute cell counts are more relevant for interpretative purposes.

SERUM CHEMISTRY
There were no test substance-related effects on serum chemistry parameters. There were significantly (p<0.05 or p<0.01) lower mean alkaline phosphatase values in the 75 (101±7.5 U/L) and 200 mg/kg bw/day (92±6.6 U/L) group F0 males but values were within the range of historical controls (version 3.1). In addition, a significantly (p<0.01) higher mean cholesterol value was noted for the 200 mg/kg bw/day group males (65±3.1 mg/dL). These group mean differences were not considered to be test substance-related.

REPRODUCTIVE PERFORMANCE
No test substance-related effects on reproductive performance were observed at any dosage level. No statistically significant differences were noted between the control and test substance-treated/exposed groups. Males that did not sire a litter numbered 1, 1, 0, and 0 in the control, 25, 75, and 200 mg/kg bw/day groups, respectively. Females that had evidence of mating but did not deliver numbered 1, 1, 0, and 0 in the same respective groups.
The mean numbers of days between pairing and coitus in the test substance-treated groups were similar to the control group value. None of these differences were statistically significant.

GESTATION LENGTH AND PARTURITION
Mean gestation lengths in the 25, 75, and 200 mg/kg bw/day groups were unaffected by test substance administration. A significantly (p<0.01) longer gestation length was noted for the 75 mg/kg bw/day group (22.0 d) compared to the concurrent control group (21.4 d). However, the magnitude of difference was small, there was no dose-related response, and the value for the 75 mg/kg bw/day group was within the range of the historical control data (21.5-22.3 d). Therefore, this difference was not attributed to test substance administration.

ANATOMIC PATHOLOGY

MACROSCOPIC EXAMINATIONS
In the 200 mg/kg bw/day group, one male was found dead on study 15 and three female were found dead on study Day 3, study Day 16, and gestation Day 13, respectively. In addition, two males in the 75 mg/kg bw/day group were euthanized in extremis on study Day 10 and 13, respectively, and one male in the 200 mg/kg bw/day group was euthanized in extremis on study Day 26. The majority of these animals in the 200 mg/kg bw/day group were noted with macroscopic findings in the gastrointestinal tract (stomach, cecum, colon, duodenum, ileum, and/or jejunum was distended, eroded, thickened, and/or had dark red areas), indicating irritation from test substance administration. All other animals survived to the scheduled necropsies.

At the scheduled necropsy, test substance-related incidences of thickened stomach were noted for the 75 and 200 mg/kg bw/day group males and females and adhesions on the liver and spleen were noted for males in the 200 mg/kg bw/day group. All other macroscopic findings occurred in single animals and/or in a manner that was not dose-related.

The mean numbers of corpora lutea, unaccounted-for sites, and implantation sites in the 25, 75, and 200 mg/kg bw/day groups were similar to the control group values.

ORGAN WEIGHTS
Mean final body weight and organ weight alterations (i.e., adrenal glands and thymus) were considered to be associated with administration of the test substance.
Also, the mean brain weight relative to final body weight was significantly (p<0.05) higher in the 200 mg/kg bw/day group males. This difference was considered secondary to the lower final body weight in this group. No other differences were statistically significant when the test substance-treated groups were compared to the control group.

MICROSCOPIC EXAMINATIONS
Test substance-related histopathologic alterations in both males and females included hypertrophy of the zona fasciculata of the adrenal cortex and ulceration, epithelial hyperplasia and hyperkeratosis, and chronic-active inflammation in the non-glandular stomach. In the 200 mg/kg bw/day group males, there was also cytoplasmic vacuolation of the zona fasciculata of the adrenal cortex, and in the 200 mg/kg bw/day group females, there was lymphoid depletion in the thymus.

Ulceration was the focal, or typically multifocal, loss of the full-thickness of mucosal epithelium. Erosion, epithelial, was the focal or multifocal loss of a partial thickness of the mucosal epithelium. Erosion was not diagnosed when ulceration was present. Hyperplasia of the squamous epithelial mucosa of the non-glandular stomach was an increased thickness and irregular basal margin of the layers of the epithelium and it was invariably accompanied by hyperkeratosis, and increased thickness of the luminal layers of keratin which was not separately diagnosed. Chronic active inflammation was attributed to neutrophils as well as mononuclear inflammatory cells along with variably increased connective tissue. Inflammation was invariable at sites of ulceration but was not diagnosed separately unless it was also observed at other sites. Inflammation was invariable in the submucosa but also extended upward into the mucosa or downward into the gastric wall. In some instances, inflammation was transmural, extending throughout the gastric muscular wall to the outer serosa, and resulted in fibrous connective tissue adhesions of the gastric serosa to either the liver or the spleen. Hypertrophy of the adrenal cortex was an increase in the size of cells in the zona fasciculata. Cytoplasmic vacuolation of the adrenal cortex also occurred in the zona fasciculata. Lymphoid depletion in the thymus was a decreased number of lymphocytes in the cortex which made the distinction between the cortex and medulla less distinct.

There were no other test substance-related histologic changes. Remaining histologic changes were considered to be incidental findings or related to some aspect of experimental manipulation other than administration of the test substance. There was no test substance-related alteration in the prevalence, severity, or histologic character of those incidental tissue alterations.

F1 LITTER DATA

PND 0 LITTER DATA AND POSTNATAL SURVIVAL
The mean number of pups born, live litter size, and the percentage of males at birth in the 25, 75, and 200 mg/kg bw/day groups were similar to the control group values. Postnatal survival in the 25, 75, and 200 mg/kg bw/day groups was unaffected by test substance administration. Differences from the control group were slight and not statistically significant.

GENERAL PHYSICAL CONDITION
The general physical condition of all F1 pups in this study were unaffected by test substance administration. Pups (litters) that were found dead numbered 15(4), 3(2), 4(3), and 4(4) in the control, 25, 75, and 200 mg/kg bw/day groups, respectively. Four (1), 0(0), 0(0), and 2(1) pups (litters) in these same respective groups were missing and presumed to have been cannibalized.

OFFSPRING BODY WEIGHTS
Mean male and female pup body weights and body weight changes in the 25, 75, and 200 mg/kg bw/day groups were unaffected by test substance administration during PND 1-4. Significantly (p<0.05 or p<0.01) higher mean male and female pup body weights were noted on PND 1 for the 75 mg/kg bw/day group. However, in the absence of a dose-related trend, these differences were not attributed to maternal test substance administration. No other statistically significant differences from the control group were noted. NECROPSIES OF PUPS FOUND DEAD

The numbers of pups (litters) found dead during PND 0-4 numbered 15(4), 3(2), 4(3), and 4(4) in the control, 25, 75, and 200 mg/kg bw/day groups, respectively. Aside from the presence or absence of milk in the stomach, no other internal findings were noted.

Dose descriptor:

NOAEL

Remarks:

for local effects

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Irritation

Critical effects observed:

not specified

Conclusions:

Under the conditions of this study, no systemic toxic effects were observed. Irritation was noted at 75 mg/kg bw and higher. The NOAEL for local irritation was therefore considered to be 25 mg/kg bw/day.

Executive summary:

A study was conducted to determine the repeated dose oral toxicity of PETIA to rat after 28 days of exposure. Lower mean body weight gains were observed during the overall study period for the 200 mg/kg bw/day males, as well as a lower mean body weight on Day 27. Test substance-related findings at 75 and 200 mg/kg bw/day relating to mortality/morbidity, adrenal gland weights, neutrophil counts, macroscopic and/or microscopic findings of the stomach, adrenal cortex and thymus were attributed to the irritative properties of the test substance and corresponding stress, rather than systemic toxicity (Stump, 2011); thus, the NOAEL for local irritation was considered to be 25 mg/kg bw/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Study duration:

subacute

Species:

rat

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: inhalation

Data waiving:

other justification

Justification for data waiving:

other:

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From September 16, 1996 to December 18, 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted by using method equivalent to standard guidelines in compliance with GLP. Pentaerythritol triacrylate is a constituent of PETIA.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Taconic Laboratory Animals and Services (Germantown, NY).
- Age at study initiation: 6 weeks
- Housing: Polycarbonate (Lab Products, Inc., Maywood, NJ), changed at least once per week, rotated every 2 weeks
- Bedding: Sani-Chip® hardwood chips (P.J. Murphy Forest Products Corp., Montville, NJ), changed at least once per week. Bedding was irradiated
- Diet: NTP-2000 pelleted diet (Zeigler Brothers, Inc., Gardners, PA), available ad libitum, changed weekly
- Water: Tap water (Columbus municipal supply) via automatic watering system (Edstrom Industries, Waterford, WI), available ad libitum
ENVIRONMENTAL CONDITIONS
- Temperature: 72°±3° F
- Humidity: 50±15%
- Air changes: 10/h
- Photoperiod: 12 h light/dark cycle

Type of coverage:

not specified

Vehicle:

acetone

Details on exposure:

TEST MATERIAL
- Amount(s) applied: 0.5 mL/kg

VEHICLE
- Lot/batch no.: KP206 and LS0051
- Purity: Greater than 99%

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The dose formulations were analysed at the beginning, midpoint, and end of the study; animal room samples of these dose formulations were also analysed. Of the dose formulations analyzed, all 15 were within 10% of the target concentration, with no value greater than 104% of the target concentration; 10 of 15 animal room samples were within 10% of the target concentration.

Duration of treatment / exposure:

3 month

Frequency of treatment:

5 days per week for 14 weeks

Remarks:

Doses / Concentrations:
0, 0.75, 1.5, 3, 6, or 12 mg/kg bw
Basis:
analytical per unit body weight

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

Animals were observed twice daily and were weighed initially, weekly, and at the end of the studies. Clinical findings were recorded weekly and at the end of the studies for core study animals. Blood was collected from the retroorbital sinus on Days 4 and 23 and at the end of the studies for hematology and clinical chemistry.
Hematology: hematocrit; hemoglobin concentration; erythrocyte, reticulocyte, and platelet counts; erythrocyte morphology; mean cell volume; mean cell hemoglobin; mean cell hemoglobin concentration; and leukocyte count and differentials
Clinical chemistry: urea nitrogen, creatinine, total protein, albumin, alanine aminotransferase, alkaline phosphatase, creatine kinase, sorbitol dehydrogenase, and bile acids

Sacrifice and pathology:

Necropsies were performed on all animals. Organs weighed were the heart, right kidney, liver, lung, right testis, and thymus. Complete histopathologic examinations were performed on vehicle control and 12 mg/kg bw rats. In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone with marrow, brain, clitoral gland, esophagus, heart with aorta, large intestine (cecum, colon, and rectum), small intestine (duodenum, jejunum, and ileum), kidney, liver, lung, lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin (site of application), spleen, stomach (forestomach and glandular), testis with epididymis and seminal vesicle, thymus, thyroid gland, trachea, urinary bladder, and uterus. The skin at the site of application was also examined.

Other examinations:

At the end of the studies, sperm samples were collected from male animals in the vehicle control and 3, 6, and 12 mg/kg bw groups for sperm count and motility evaluations. The following parameters were evaluated: spermatid heads per testis or cauda and per gram testis or cauda and epididymal spermatozoal motility. The left cauda, left epididymis, and left testis were weighed. Vaginal samples were collected for up to 12 consecutive days prior to the end of the studies from females in the vehicle control and 3, 6, and 12 mg/kg bw groups for vaginal cytology evaluations. The percentage of time spent in the various estrous cycle stages and estrous cycle length were evaluated.

Dermal irritation:

effects observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Details on results:

All rats survived to the end of the study. Final mean body weights and body weight gains of 12 mg/kg bw males were significantly less than those of the vehicle controls. Irritation at the site of application occurred in 12 mg/kg bw rats.

On Day 23, an increase in segmented neutrophils occurred in 12 mg/kg bw males and females. At study termination, an increased neutrophil count occurred in 6 mg/kg bw males. The neutrophilia would be consistent with skin inflammation observed microscopically. No other hematology or clinical chemistry changes were considered to be toxicologically relevant.

Thymus weights of males administered 3 mg/kg bw or greater were significantly less than those of the vehicle controls. There were no significant differences in sperm motility or vaginal cytology parameters between dosed groups and the vehicle controls.

No treatment-related lesions were observed grossly in rats except irritation at the site of application in the 12 mg/kg bw groups. Microscopically, the primary changes at the site of application consisted of epidermal hyperplasia, hyperkeratosis, epidermal degeneration and necrosis, and chronic active inflammation. The incidence and severity of hyperplasia increased with increasing dose; most animals administered 3 mg/kg bw or greater were affected. Severity was minimal to mild and characterized by focally extensive to diffuse increased thickness of the epidermis, from the normal one to three cell layers thick to four to six layers thick. Hyperplasia was accompanied by minimal to mild increased thickness of the superficial keratin layer (hyperkeratosis). Minimal hyperkeratosis without accompanying hyperplasia was present in the 0.75 and 1.5 mg/kg bw groups. Degeneration was diagnosed in many animals treated with 1.5 mg/kg bw or greater.

Degeneration was a minimal focal change consisting of intraepidermal vacuolization, presumably due to intra or intercellular fluid accumulation. Vacuoles occasionally coalesced to form small vesicles that contained a few neutrophils. Epidermal necrosis was present in some males, although a dose-related response was not clear. Necrosis consisted of partial to full-thickness coagulative change of the epidermis and was likely a pathogenic sequela of degeneration. Intraepidermal infiltration of neutrophils (suppurative inflammation) often accompanied degeneration or necrosis of the epidermis. A mixed inflammatory cell infiltrate (chronic active inflammation) was present in the dermis of animals administered 1.5 mg/kg bw or greater, with dose dependent increases in incidences and severity. Sebaceous glands at the site of application were slightly enlarged and prominent in animals with the other changes described above.

Dose descriptor:

NOAEL

Effect level:

0.75 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: Irritation

Critical effects observed:

not specified

Executive summary:

A study was conducted to assess the repeated dose dermal toxicity of the test substance in male and female rats.

Groups of 10 male and 10 female rats received dermal applications of 0, 0.75, 1.5, 3, 6, or 12 mg/kg bw of test substance in acetone, 5 days per week for 14 weeks; the dosing volume was 0.5 mL/kg bw. Animals were observed twice daily and were weighed initially, weekly, and at the end of the studies. Clinical findings were recorded weekly and at the end of the studies for core study animals. Necropsies were performed on all animals. Organs weighed were the heart, right kidney, liver, lung, right testis, and thymus. Blood was collected from the retroorbital sinus on Days 4, 23 and at the end of the studies for hematology and clinical chemistry.

All rats survived to the end of the study. Final mean body weights and body weight gains of 12 mg/kg bw males were significantly less than those of the vehicle controls. Irritation at the site of application occurred in 12 mg/kg bw rats. On Day 23, an increase in segmented neutrophils occurred in 12 mg/kg bw males and females. At study termination, an increased neutrophil count occurred in 6 mg/kg bw males. The neutrophilia would be consistent with skin inflammation observed microscopically. No other hematology or clinical chemistry changes were considered to be toxicologically relevant. Thymus weights of males administered 3 mg/kg bw or greater were significantly less than those of the vehicle controls. There were no significant differences in sperm motility or vaginal cytology parameters between dosed groups and the vehicle controls. No treatment-related lesions were observed grossly in rats except irritation at the site of application in the 12 mg/kg bw groups. Microscopically, the primary changes at the site of application consisted of epidermal hyperplasia, hyperkeratosis, epidermal degeneration and necrosis, and chronic active inflammation. The local NOAEL for this study could be considered to be 0.75 mg/kg bw/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From September 16, 1996 to December 18, 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted by using method equivalent to standard guidelines in compliance with GLP. Pentaerythritol triacrylate is a constituent of PETIA.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Taconic Laboratory Animals and Services (Germantown, NY).
- Age at study initiation: 6 weeks
- Housing: Polycarbonate (Lab Products, Inc., Maywood, NJ), changed at least once per week, rotated every 2 weeks
- Bedding: Sani-Chip® hardwood chips (P.J. Murphy Forest Products Corp., Montville, NJ), changed at least once per week. Bedding was irradiated
- Diet: NTP-2000 pelleted diet (Zeigler Brothers, Inc., Gardners, PA), available ad libitum, changed weekly
- Water: Tap water (Columbus municipal supply) via automatic watering system (Edstrom Industries, Waterford, WI), available ad libitum
ENVIRONMENTAL CONDITIONS
- Temperature: 72°±3° F
- Humidity: 50±15%
- Air changes: 10/h
- Photoperiod: 12 h light/dark cycle

Type of coverage:

not specified

Vehicle:

acetone

Details on exposure:

TEST MATERIAL
- Amount(s) applied: 0.5 mL/kg

VEHICLE
- Lot/batch no.: KP206 and LS0051
- Purity: Greater than 99%

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The dose formulations were analysed at the beginning, midpoint, and end of the study; animal room samples of these dose formulations were also analysed. Of the dose formulations analyzed, all 15 were within 10% of the target concentration, with no value greater than 104% of the target concentration; 10 of 15 animal room samples were within 10% of the target concentration.

Duration of treatment / exposure:

3 month

Frequency of treatment:

5 days per week for 14 weeks

Remarks:

Doses / Concentrations:
0, 0.75, 1.5, 3, 6, or 12 mg/kg bw
Basis:
analytical per unit body weight

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

Animals were observed twice daily and were weighed initially, weekly, and at the end of the studies. Clinical findings were recorded weekly and at the end of the studies for core study animals. Blood was collected from the retroorbital sinus on Days 4 and 23 and at the end of the studies for hematology and clinical chemistry.
Hematology: hematocrit; hemoglobin concentration; erythrocyte, reticulocyte, and platelet counts; erythrocyte morphology; mean cell volume; mean cell hemoglobin; mean cell hemoglobin concentration; and leukocyte count and differentials
Clinical chemistry: urea nitrogen, creatinine, total protein, albumin, alanine aminotransferase, alkaline phosphatase, creatine kinase, sorbitol dehydrogenase, and bile acids

Sacrifice and pathology:

Necropsies were performed on all animals. Organs weighed were the heart, right kidney, liver, lung, right testis, and thymus. Complete histopathologic examinations were performed on vehicle control and 12 mg/kg bw rats. In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone with marrow, brain, clitoral gland, esophagus, heart with aorta, large intestine (cecum, colon, and rectum), small intestine (duodenum, jejunum, and ileum), kidney, liver, lung, lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin (site of application), spleen, stomach (forestomach and glandular), testis with epididymis and seminal vesicle, thymus, thyroid gland, trachea, urinary bladder, and uterus. The skin at the site of application was also examined.

Other examinations:

At the end of the studies, sperm samples were collected from male animals in the vehicle control and 3, 6, and 12 mg/kg bw groups for sperm count and motility evaluations. The following parameters were evaluated: spermatid heads per testis or cauda and per gram testis or cauda and epididymal spermatozoal motility. The left cauda, left epididymis, and left testis were weighed. Vaginal samples were collected for up to 12 consecutive days prior to the end of the studies from females in the vehicle control and 3, 6, and 12 mg/kg bw groups for vaginal cytology evaluations. The percentage of time spent in the various estrous cycle stages and estrous cycle length were evaluated.

Dermal irritation:

effects observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Details on results:

All rats survived to the end of the study. Final mean body weights and body weight gains of 12 mg/kg bw males were significantly less than those of the vehicle controls. Irritation at the site of application occurred in 12 mg/kg bw rats.

On Day 23, an increase in segmented neutrophils occurred in 12 mg/kg bw males and females. At study termination, an increased neutrophil count occurred in 6 mg/kg bw males. The neutrophilia would be consistent with skin inflammation observed microscopically. No other hematology or clinical chemistry changes were considered to be toxicologically relevant.

Thymus weights of males administered 3 mg/kg bw or greater were significantly less than those of the vehicle controls. There were no significant differences in sperm motility or vaginal cytology parameters between dosed groups and the vehicle controls.

No treatment-related lesions were observed grossly in rats except irritation at the site of application in the 12 mg/kg bw groups. Microscopically, the primary changes at the site of application consisted of epidermal hyperplasia, hyperkeratosis, epidermal degeneration and necrosis, and chronic active inflammation. The incidence and severity of hyperplasia increased with increasing dose; most animals administered 3 mg/kg bw or greater were affected. Severity was minimal to mild and characterized by focally extensive to diffuse increased thickness of the epidermis, from the normal one to three cell layers thick to four to six layers thick. Hyperplasia was accompanied by minimal to mild increased thickness of the superficial keratin layer (hyperkeratosis). Minimal hyperkeratosis without accompanying hyperplasia was present in the 0.75 and 1.5 mg/kg bw groups. Degeneration was diagnosed in many animals treated with 1.5 mg/kg bw or greater.

Degeneration was a minimal focal change consisting of intraepidermal vacuolization, presumably due to intra or intercellular fluid accumulation. Vacuoles occasionally coalesced to form small vesicles that contained a few neutrophils. Epidermal necrosis was present in some males, although a dose-related response was not clear. Necrosis consisted of partial to full-thickness coagulative change of the epidermis and was likely a pathogenic sequela of degeneration. Intraepidermal infiltration of neutrophils (suppurative inflammation) often accompanied degeneration or necrosis of the epidermis. A mixed inflammatory cell infiltrate (chronic active inflammation) was present in the dermis of animals administered 1.5 mg/kg bw or greater, with dose dependent increases in incidences and severity. Sebaceous glands at the site of application were slightly enlarged and prominent in animals with the other changes described above.

Dose descriptor:

NOAEL

Effect level:

0.75 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: Irritation

Critical effects observed:

not specified

Executive summary:

A study was conducted to assess the repeated dose dermal toxicity of the test substance in male and female rats.

Groups of 10 male and 10 female rats received dermal applications of 0, 0.75, 1.5, 3, 6, or 12 mg/kg bw of test substance in acetone, 5 days per week for 14 weeks; the dosing volume was 0.5 mL/kg bw. Animals were observed twice daily and were weighed initially, weekly, and at the end of the studies. Clinical findings were recorded weekly and at the end of the studies for core study animals. Necropsies were performed on all animals. Organs weighed were the heart, right kidney, liver, lung, right testis, and thymus. Blood was collected from the retroorbital sinus on Days 4, 23 and at the end of the studies for hematology and clinical chemistry.

All rats survived to the end of the study. Final mean body weights and body weight gains of 12 mg/kg bw males were significantly less than those of the vehicle controls. Irritation at the site of application occurred in 12 mg/kg bw rats. On Day 23, an increase in segmented neutrophils occurred in 12 mg/kg bw males and females. At study termination, an increased neutrophil count occurred in 6 mg/kg bw males. The neutrophilia would be consistent with skin inflammation observed microscopically. No other hematology or clinical chemistry changes were considered to be toxicologically relevant. Thymus weights of males administered 3 mg/kg bw or greater were significantly less than those of the vehicle controls. There were no significant differences in sperm motility or vaginal cytology parameters between dosed groups and the vehicle controls. No treatment-related lesions were observed grossly in rats except irritation at the site of application in the 12 mg/kg bw groups. Microscopically, the primary changes at the site of application consisted of epidermal hyperplasia, hyperkeratosis, epidermal degeneration and necrosis, and chronic active inflammation. The local NOAEL for this study could be considered to be 0.75 mg/kg bw/day.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Study duration:

subchronic

Species:

rat

Additional information

Oral

A study was conducted to determine the repeated dose oral toxicity of PETIA to rat after 28 days of exposure. Lower mean body weight gains were observed during the overall study period for the 200 mg/kg bw/day males, as well as a lower mean body weight on Day 27. Test substance-related findings at 75 and 200 mg/kg bw/day relating to mortality/morbidity, adrenal gland weights, neutrophil counts, macroscopic and/or microscopic findings of the stomach, adrenal cortex and thymus were attributed to the irritative properties of the test substance and corresponding stress, rather than systemic toxicity (Stump, 2011); thus, the NOAEL for local irritation was considered to be 25 mg/kg bw/day.

Dermal

A 2 week study was conducted to assess the repeated dose dermal toxicity of PETIA in mice, 5 days per week for 17 days at 0, 12.5, 25, 50, 100 or 200 mg/kg bw/day. The animals were weighed pre-test, on Day 8 and at the end of the study. Clinical findings were recorded daily. Necropsies were performed on all animals. The heart, right kidney, liver, lung, right testis and thymus were weighed. Histopathologic examinations were performed on the skin (site of application) thymus of all mice. All mice survived to the end of the study. The final mean body weight and body weight gain of 25 mg/kg bw males were significantly greater than those of the vehicle controls, as was the mean body weight gain of 50 mg/kg bw males. Irritation at the site of application occurred in all dosed groups. Thymus weights of 50 mg/kg bw or greater males and of 200 mg/kg bw females were significantly lower than those of controls. Crusts were observed grossly at the site of application in all dosed groups. Microscopically, lesions were found at the site of application in all dosed groups. Epidermal hyperplasia, hyperkeratosis, and sebaceous gland hyperplasia were found in most 12.5 mg/kg bw mice. These lesions were characterized by increased layers of epidermal cells, a thickened keratin layer and prominence of sebaceous glands. More severe lesions that tended to occur at higher doses were ulcer (focal full-thickness necrosis of the epidermis), degeneration (vacuolar change of epidermal cells), parakeratosis (retention of nuclei in the keratin layer), dermal chronic active inflammation (mixed inflammatory cell infiltrate) and epidermal suppurative inflammation (accumulation of neutrophils) in the degenerative and parakeratotic areas of the superficial epidermis. These lesions were not seen in the vehicle controls and their severity generally increased with dose. Under the conditions of the study, skin was the major target organ. The effects seem to be due to local irritation properties of the test substance (Hejtmancik, 2005).

A 2 week study was conducted to assess the repeated dose dermal toxicity of PETIA in rats. Groups of five male and five female rats received dermal applications of 0, 12.5, 25, 50, 100, or 200 mg/kg bw of test substance in acetone, 5 d per week for 17 d. The animals were weighed initially, on Day 8, and at the end of the studies. Clinical findings were recorded daily. Necropsies were performed on all rats. The heart, right kidney, liver, lung, right testis and thymus were weighed. Histopathologic examinations were performed on the skin (site of application) of all rats. All rats survived to the end of the study. Final organ mean body weights and body weight gains of males administered 50 mg/kg bw or greater and 200 mg/kg bw females were less than those of the vehicle controls. Irritation at the site of application occurred in all dosed groups except 12.5 mg/kg bw females. Differences in organ weights were not considered biologically significant. Crusts at the site of application were observed grossly in all dosed groups except 12.5 mg/kg bw/day females. Microscopically, lesions occurred at the site of application in all dosed groups. In the 12.5 mg/kg bw/day group, epidermal hyperplasia, hyperkeratosis, and sebaceous gland hyperplasia were found in all treated rats and were characterized by increased layers of epidermal cells, thickened keratin layer, and prominence of sebaceous glands. More severe lesions occurred at doses of 25 mg/kg bw or greater and consisted of ulcer (focal full-thickness necrosis of the epidermis), degeneration (vacuolar change of epidermal cells), parakeratosis (retention of nuclei in keratin layer), mixed inflammatory infiltrate of the dermis (chronic active inflammation), and accumulation of neutrophils (suppurative inflammation) in the degenerative and parakeratotic areas of the superficial epidermis. These lesions were not seen in the vehicle controls and their severity generally increased with increasing dose. Under the conditions of the study, the test substance caused dose-related hyperplastic, vacuolar degenerative and ultimately necrotizing lesions of the epidermis, accompanied by hyperplasia of sebaceous glands and a dermal chronic inflammation in male and female rats. These effects seem to be due to local irritation properties of the test substance (Hejtmancik, 2005).

A 3 month study was conducted to assess the repeated dose dermal toxicity of PETIA in mice. Groups of 10 male and 10 female mice received dermal applications of 0, 0.75, 1.5, 3, 6, or 12 mg/kg bw of test substance in acetone, 5 days per week for 14 weeks. Animals were observed twice daily and were weighed initially, weekly and at the end of the studies. Clinical findings were recorded weekly and at the end of the studies for core study animals. Blood was collected from the retroorbital sinus from core study mice at the end of the study for hematology. Necropsies were performed on all animals. Organs weighed were the heart, right kidney, liver, lung, right testis, and thymus. Complete histopathologic examinations were performed on vehicle control and 12 mg/kg bw mice. At the end of the studies, sperm samples were collected from male animals in the vehicle control and 3, 6, and 12 mg/kg bw groups for sperm count and motility evaluations. Mean body weights of dosed groups were similar to those of the vehicle control groups. Irritation at the site of application occurred in the 6 and 12 mg/kg bw male groups. Hematology results indicated an increased neutrophil count consistent with an inflammatory response related to the dermatitis observed histopathologically. There also was a minimal decrease in the erythron (hematocrit, hemoglobin concentration, and erythrocyte count) likely secondary to the inflammatory skin process. There were no biologically significant differences in organ weights between dosed and vehicle control groups. No lesions were observed grossly in mice except irritation at the site of application in 6 and 12 mg/kg bw males. The primary microscopic changes at the site of application were epidermal hyperplasia, degeneration, and necrosis; dermal chronic active inflammation, and sebaceous gland hyperplasia (Hejtmancik, 2005). The local NOAEL for this study could be considered to be 1.5 mg/kg bw/day.

A 3 month study was conducted to assess the repeated dose dermal toxicity of PETIA in rats. Groups of 10 male and 10 female rats received dermal applications of 0, 0.75, 1.5, 3, 6, or 12 mg/kg bw of test substance in acetone, 5 days per week for 14 weeks. Animals were observed twice daily and were weighed initially, weekly and at the end of the studies. Clinical findings were recorded weekly and at the end of the studies for core study animals. Necropsies were performed on all animals. Organs weighed were the heart, right kidney, liver, lung, right testis, and thymus. Blood was collected from the retroorbital sinus on Days 4, 23 and at the end of the studies for hematology and clinical chemistry. All rats survived to the end of the study. Final mean body weights and body weight gains of 12 mg/kg bw males were significantly less than those of the vehicle controls. Irritation at the site of application occurred in 12 mg/kg bw rats. On Day 23, an increase in segmented neutrophils occurred in 12 mg/kg bw males and females. At study termination, an increased neutrophil count occurred in 6 mg/kg bw males. The neutrophilia would be consistent with skin inflammation observed microscopically. No other hematology or clinical chemistry changes were considered to be toxicologically relevant. Thymus weights of males administered 3 mg/kg bw or greater were significantly less than those of the vehicle controls. There were no significant differences in sperm motility or vaginal cytology parameters between dosed groups and the vehicle controls. No treatment-related lesions were observed grossly in rats except irritation at the site of application in the 12 mg/kg bw groups. Microscopically, the primary changes at the site of application consisted of epidermal hyperplasia, hyperkeratosis, epidermal degeneration and necrosis, and chronic active inflammation (Hejtmancik, 2005). The local NOAEL for this study could be considered to be 0.75 mg/kg bw/day.

Justification for classification or non-classification

Repeated dose oral toxicity information may be derived from a 28 day oral toxicity study conducted in rats. No systemic effects were observed throughout the study. Treatment-related effects noted as of 75 mg/kg bw/day were attributed to the irritating properties of the test substance and corresponding stress, rather than systemic toxicity. Thus, the NOAEL for local irritation was 25 mg/kg bw/day. On this basis, PETIA does not meet the criteria for classification for this endpoint according to CLP (EC 1272/2008/EC) criteria.

In repeated dose dermal toxicity studies conducted with mice and rats, the effects observed were all related to the inflammation at the site of application caused by the irritating properties of the substance.

Exposure to PETIA may occur, if at all, only at the workplace. In this environment, appropriate risk management measures are in place to reduce contact/exposure (see CSR Chapter 9). Repeated exposure via the inhalation or dermal routes is therefore not expected to pose an issue for human health. Repeated oral exposure is not expected at the workplace.