2,2,3,3,4,4,5,5-octafluoropentyl methacrylate

Endpoint summary

Description of key information

The test article was well tolerated following 7-day oral gavage in male and female rats at 100 and 300 mg/kg/day.

The no-observed-adverse-effect level (NOAEL) for nose-only inhalation exposure of the test substance to rats for 5 consecutive days was 168 ppm, the highest exposure concentration tested.

No adverse effects were noted following repeated dermal exposure for 28 -days at the dose level of 1,300 mg/kg bw/day.

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:

7-day range-finding tolerability study

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

24 October 2008 to 29 January 2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Guideline:

other: In-house 7-day repeated oral dose protocol

Principles of method if other than guideline:

In-house protocol. The notified chemical in the vehicle, corn oil, was administered orally by gavage once daily for 7 consecutive days to 3 groups of test animals at the dose levels of 100, 300 and 1,000 mg/kg bw/day. A concurrent control group received vehicle only on a comparable regimen. The dose volume was 5 mL/kg bw for all groups. Following 7 days of dose administration, all test animals were euthanized for gross necropsies.

During the study, all test animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily at the time of dosing and approximately 1 and 4 hours post-dosing and detailed physical examinations were performed weekly. Individual body weight and food consumption were recorded on study Days 0 and 7.

GLP compliance:

no

Remarks:

The study was not commissioned with compliance with REACH as a goal, rather the study was commissioned during early product development.

Limit test:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Lot no. Q151-170
- purity: 99.0%

Species:

rat

Strain:

Crj: CD(SD)

Details on species / strain selection:

This species and strain of animal is recognized as appropriate for subchronic toxicity studies. The Sprague Dawley rat was selected because it is a widely used strain for which significant historical control data are available.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, NC
- Females nulliparous and non-pregnant: yes
- Age at study initiation: approximately 8 weeks old at the initiation of dose administration
- Weight at study initiation: 281 g to 322 g for males and from 182 g to 233 g for females at the initiation of dosing
- Housing: housed individually
- Diet: ad libitum throughout the study
- Water: ad libitum throughout the study
- Acclimation period: 14-day acclimation/pretest period

DETAILS OF FOOD AND WATER QUALITY:
Food: PMI Nutrition International, LLC, Certified Rodent LabDiet® 5002 meal
Water: Reverse osmosis-treated (on-site) drinking water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.3°C to 21.5°C
- Humidity (%): 40.4% to 49.9%
- Air changes (per hr): a minimum of 10 fresh air changes per hour
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 29 October 2008 To: 5 November 2008

Route of administration:

oral: gavage

Details on route of administration:

The dose volume for all groups was 5 mL/kg.

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: The test article formulations were volume/volume (test article/vehicle) mixtures. The test article formulations were prepared daily as single formulations for each dosage level, divided into aliquots for daily dispensation and stored at room temperature. The test article formulations were stirred continuously throughout the preparation, sampling and dose administration procedures. Due to the nature of the vehicle, the pH was not measured.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The accuracy and stability of the test substance at 3 concentrations was confirmed using High Pressure Liquid Chromatography (HPLC). The results indicated that the three formulations used for dose levels 100, 300, and 1000 mg/kg bw were within +/- 10% of the target concentrations. Also the traces revealed a clear peak for the test substance and no incipient peaks.

Duration of treatment / exposure:

once daily for 7 consecutive days

Frequency of treatment:

once daily for 7 consecutive days

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

300 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

5/sex/dose

Control animals:

yes, concurrent vehicle

Details on study design:

The notified chemical in the vehicle, corn oil, was administered orally by gavage once daily for 7 consecutive days to 3 groups of test animals at the dose levels of 100, 300 and 1,000 mg/kg bw/day. A concurrent control group received vehicle only on a comparable regimen. The dose volume was 5 mL/kg bw for all groups. Following 7 days of dose administration, all test animals were euthanized for gross necropsies.

Positive control:

None

Observations and examinations performed and frequency:

During the study, all test animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily at the time of dosing and approximately 1 and 4 hours post-dosing and detailed physical examinations were performed weekly. Individual body weight and food consumption were recorded on study Days 0 and 7.

Sacrifice and pathology:

A gross necropsy was conducted for all animals. The necropsies included examination of the external surface, all orifices, and the cranial, thoracic, abdominal and pelvic cavities, including viscera.

Other examinations:

None

Statistics:

All statistical tests were performed using appropriate computing devices or programs.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Test substance related clinical observations noted in the 1,000 mg/kg bw/day group as early as study Day 0 and throughout 7-day dosing period included impaired muscle coordination and/or impaired equilibrium in both sexes of the test animals with higher frequency in females. Hypoactivity, decreased respiration rate and prostration were noted in females on study Day 0. These effects did not persist to the 4-hour post-dosing observation on study Days 0 to 6 for males and study Days 4 to 6 for females. These effects were considered by the study authors as adverse since they persisted throughout the 7-day dosing period at approximately 1 hour post-dosing. No significant clinical observations were recorded in the 100 and 300 mg/kg bw/day groups.

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

A test substance related effect on body weight was noted in test substance treated animals, showing a trend towards slightly lower body weight gains. However, this effect was not considered by the study authors as adverse.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related effects on food consumption.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

No significant macroscopic findings noted.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Key result

Dose descriptor:

NOAEL

Remarks:

7 days

Effect level:

300 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

gross pathology

mortality

Critical effects observed:

yes

Lowest effective dose / conc.:

1 000 mg/kg bw/day (nominal)

Organ:

not specified

Treatment related:

yes

Dose response relationship:

not specified

Relevant for humans:

not specified

Conclusions:

Based on the results of this study, adverse toxicity of the test substance administered orally (gavage) to rats for 7 consecutive days was observed at 1000 mg/kg/day as evidenced by clinical observations noted following dosing throughout the 7-day dosing period. The test article was well tolerated in male and female rats at 100 and 300 mg/kg/day.

Executive summary:

The test substance in the vehicle, corn oil, was administered orally by gavage once daily for 7 consecutive days to 3 groups (Groups 2-3) of rats. Dosage levels were 100, 300 and 1000 mg/kg/day. A concurrent control group (Group 1) received the vehicle on a comparable regimen. The dose volume was 5 mL/kg for all groups. Each group (Groups 1-4) consisted of 5 animals/sex. Following 7 days of dose administration, all rats were euthanized.

 

All animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily at the time of dosing and approximately 1 and 4 hours post-dosing, and detailed physical examinations were performed weekly. Individual body weight and food consumption were recorded on study days 0 and 7. All carcasses were discarded following examination and collection of gross lesions.

 

All animals survived to the scheduled necropsy. There were no test article-related effects on food consumption and there were no significant macroscopic findings. There were no significant clinical observations in the 100 and 300 mg/kg/day groups.

 

Test article-related clinical observations noted in the 1000 mg/kg/day group as early as study day 0 and throughout the 7-day dosing period included impaired muscle coordination and/or impaired equilibrium in males and females; hypoactivity, decreased respiration rate, and prostration were also noted in females on study day 0. These effects did not persist to the 4-hour post-dose observation on study days 0-6 for males and study days 4-6 for females. These clinical observations were considered adverse, especially since they persisted throughout the 7-day dosing period at approximately 1-hour post-dosing.

 

A test article-related effect on body weight included a trend towards slightly lower body weight gains noted in all test article-treated groups compared to the control group. However, the changes in body weights were not of a magnitude to be considered adverse.

 

Based on the results of this study, adverse toxicity of the test substance administered orally (gavage) to rats for 7 consecutive days was observed at 1000 mg/kg/day as evidenced by clinical observations noted following dosing throughout the 7-day dosing period. The test article was well tolerated in male and female rats at 100 and 300 mg/kg/day.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The database is robust given the number and type of studies available, and consistency of findings

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: inhalation

Remarks:

5-day study

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

14 July 2009 to 31 August 2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Guideline:

other: In-house protocol for 5-day nose-only inhalation

Principles of method if other than guideline:

In-house protocol. The test substance was administered to test animals via nose-only inhalation for 6 hours per day for 5 consecutive days at targeted vapour dose levels of 42, 84 and 168 ppm. A concurrent control group was exposed to filtered air on a comparable regimen. On the day following the fifth exposure, all test animals were euthanized and subjected to necropsy.

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Lot no. 900638318
- Purity: 99.7%

Species:

rat

Strain:

other: Crl:CD(SD)

Details on species / strain selection:

This species and strain of animal is recognized as appropriate for inhalation studies. The Sprague Dawley rat was selected because it is a widely used strain for which significant historical control data are available.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, NC
- Females nulliparous and non-pregnant: yes
- Age at study initiation: approximately 7-9 weeks of age at initiation of exposures
- Weight at study initiation: Males - 206-251 g; Females - 147-181 g
- Housing:housed individually
- Diet: ad libitum throughout the study except during restraint acclimation, exposure periods, and prior to the scheduled necropsy.
- Water:ad libitum throughout the study except during restraint acclimation, exposure periods, and prior to the scheduled necropsy.
- Acclimation period: 12 days acclimation/pretest period; 5 days in nose-only exposure tubes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.2°C to 21.8°C
- Humidity (%): 43.1% to 47.5%
- Air changes (per hr): a minimum of 10 fresh air changes per hour
- Photoperiod (hrs dark / hrs light):12 / 12

IN-LIFE DATES: From: 26 July 2009 To: 31 July 2009

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

other: nitrogen gas mixed with filtered air

Details on inhalation exposure:

In-house protocol. The test substance was administered to test animals via nose-only inhalation for 6 hours per day for 5 consecutive days at targeted vapour dose levels of 42, 84 and 168 ppm. A concurrent control group was exposed to filtered air on a comparable regimen.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyzed exposure concentrations were determined at approximately 35-minute intervals using an appropriate gas chromatography (GC) method. During the method development phase of the study, the stability over time and the spatial homogeneity of the test substance vapour concentration within each test chamber were evaluated. The stability and homogeneity results were considered to be adequate for the purpose of this study. During the method development phase, the test substance exposure systems were monitored for aerosol formation. Aerosol formation was not observed in any test substance exposure system.

Duration of treatment / exposure:

The test substance or compressed air (control group) was administered as a daily 6-hour nose-only inhalation exposure for 5 days.

Frequency of treatment:

The test substance or compressed air (control group) was administered as a daily 6-hour nose-only inhalation exposure for 5 consecutive days.

Dose / conc.:

81 ppm (nominal)

Remarks:

targeted: 42 ppm, actual 40 ppm

Dose / conc.:

169 ppm (nominal)

Remarks:

targeted: 84 ppm; actual: 89 ppm

Dose / conc.:

219 ppm (nominal)

Remarks:

targeted: 168 ppm; actual: 168 ppm

No. of animals per sex per dose:

5/sex/dose

Control animals:

yes

Details on study design:

The test substance exposure concentrations were selected by the Sponsor based on toxicity information from structurally related materials and levels needed to provide adequate safety margins based on estimated human exposure levels.

Positive control:

None

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: All animals were observed twice daily, once in the morning and once in the afternoon, for mortality and moribundity.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Clinical examinations were performed 3 times daily, prior to exposure, during exposure (at the approximate midpoint), and approximately 0-1 hour following the end of exposure (designated as 1 hour post-exposure for report presentation purposes).

BODY WEIGHT: Yes
- Time schedule for examinations: Individual body weights were recorded during the pretest period, prior to randomization, and prior to the first (study day 0) and last (study day 4) exposures.

FOOD CONSUMPTION AND COMPOUND INTAKE: Individual food consumption was recorded for 1 week during the pretest period and on study days 0 and 4.

Sacrifice and pathology:

On the day following the fifth exposure, all test animals were euthanized and subjected to necropsy. Microscopic examination was performed on all animals in the control and 168 ppm groups (Groups 1 and 4, respectively) at the scheduled necropsy. Gross lesions were examined from all animals.

Statistics:

All statistical tests were performed using appropriate computing devices or programs.

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

All clinical findings in the test substance-treated groups were noted with similar incidence in the control group, were limited to single animals, were not noted in a dose-related manner and/or were common findings for laboratory rats of this age and strain.

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related macroscopic findings at the scheduled necropsy. All macroscopic findings noted were considered to be spontaneous and/or incidental in nature and unrelated to test substance administration.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related microscopic findings. All findings observed were consistent with normal background lesions in clinically normal rats of the age and strain used on this study and were considered spontaneous and/or incidental in nature and unrelated to test substance administration.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Key result

Dose descriptor:

NOAEL

Effect level:

168 ppm (analytical)

Based on:

test mat.

Remarks:

highest concentration tested

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical signs

gross pathology

histopathology: non-neoplastic

mortality

organ weights and organ / body weight ratios

Critical effects observed:

no

Conclusions:

Based on the results of this study, exposure of rats to the test substance via 6-hour nose-only inhalation for 5 consecutive days at exposure concentrations ≤168 ppm did not result in any test substance-related effects or dose-limiting toxicity. Therefore, the no-observed-adverse-effect level (NOAEL) for nose-only inhalation exposure of the test substance to rats for 5 consecutive days was 168 ppm, the highest exposure concentration tested.

Executive summary:

The test substance was administered via nose-only inhalation for 6 hours per day for 5 consecutive days to 3 groups (Groups 2, 3, and 4) of rats. Target exposure concentrations were 42, 84, and 168 ppm for Groups 2, 3, and 4, respectively. A concurrent control group (Group 1) was exposed to filtered air on a comparable regimen. Each group consisted of 5 animals/sex. On the day following the fifth exposure, all animals were euthanized and subjected to necropsy.

 

The animals were observed twice daily for mortality and moribundity. Clinical examinations were performed 3 times daily (prior to exposure, at the approximate exposure midpoint, and approximately 0 to 1 hour following the end of exposure), and detailed physical examinations were performed for randomization and during the exposure phase on study days 0 and 4. Individual body weights and food consumption were recorded at least weekly during the pretest phase and on study days 0 and 4. Complete necropsies were performed on all animals, and the liver, lungs, and kidneys were weighed at the scheduled necropsy. The kidneys, larynx, liver, lungs, nasal cavity (with turbinates), pharynx, trachea, and urinary bladder were examined microscopically from all animals in the control and 168 ppm group (Groups 1 and 4, respectively). Gross lesions were examined microscopically from all animals (when possible).

 

There were no test substance-related effects on survival or clinical observations. There were no apparent test substance-related effects on body weights, body weight changes, food consumption, organ weights, or macroscopic and microscopic findings at any exposure concentration.

 

Based on the results of this study, exposure of rats to the test substance via 6-hour nose-only inhalation for 5 consecutive days at exposure concentrations ≤168 ppm did not result in any test substance-related effects or dose-limiting toxicity. Therefore, the no-observed-adverse-effect level (NOAEL) for nose-only inhalation exposure of the test substance to rats for 5 consecutive days was 168 ppm, the highest exposure concentration tested.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

2 100 mg/m³

Study duration:

subacute

Species:

rat

Quality of whole database:

The database is robust given the number and type of studies available, and consistency of findings

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2 October 2007 to 14 January 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)

Deviations:

yes

Remarks:

Only 8% of the body surface was covered

GLP compliance:

no

Remarks:

The study was not commissioned with compliance with REACH as a goal, rather the study was commissioned during early product development.

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Q14A-14
- Purity: 99%

Species:

rat

Strain:

other: Crl:CD(SD)

Details on species / strain selection:

The Sprague-Dawley rat was used because it is a widely used strain for which significant historical control data are available.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, North Carolina
- Females nulliparous and non-pregnant: yes
- Age at study initiation: The animals were approximately 58 days old at the initiation of dose administration.
- Weight at study initiation: individual body weights ranged from 260 g to 298 g for males and from 190 g to 220 g for females.
- Housing: housed individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 10 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 68.2°F to 70.6°F (20.1°C to 21.4°C)
- Humidity (%): 33.6% to 52.2%
- Air changes (per hr): minimum of 10 fresh air changes per hour.
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 10 October 2007 To: 9 November 2007

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on exposure:

The test was conducted as non-GLP study. The test substance at the level of 0.91 mL/kg bw (equivalent to 1,300 mg/kg bw based on the density of 1.432 g/mL) was dosed to individual animals via dermal application to clipped dorsum under occlusive conditions once daily for a minimum of 6 hours per day for 28 consecutive days.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples were typically within 4% of expected concentration. Examination of the HPLC chromatograms showed OFPMA eluting near 1.55 minutes as expected, and revealed no incipient peaks.

Duration of treatment / exposure:

A minimum of 6 hours per day for 28 consecutive days.

Frequency of treatment:

28 consecutive days

Dose / conc.:

1 300 mg/kg bw/day (nominal)

No. of animals per sex per dose:

10/sex/dose

Control animals:

yes

Positive control:

None

Observations and examinations performed and frequency:

All animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily. Detailed clinical examinations were performed weekly.

Sacrifice and pathology:

Pathology evaluations were performed on all animals on the day of scheduled necropsy (Day 28 of the study). Complete necropsies were conducted on all animals.

Other examinations:

Application sites were examined once per week at the time of the detailed physical examination and treated and untreated skin was examined macroscopically and microscopically. Individual body weights and food consumption were recorded weekly. Ophthalmic examinations were performed during study weeks -2 and 3. Blood and urine samples for clinical pathology evaluations (hematology, coagulation, serum chemistry and urinalysis) were collected from all animals on the day of the scheduled necropsy (study day 28).

Statistics:

All statistical tests were performed using appropriate computing devices or programs.

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related effects noted on clinical findings, including dermal observations.

Dermal irritation:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related effects noted on clinical findings, including dermal observations.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One male in test group was found dead on Day 13 of the study. The cause of the death was undetermined. Due to lack of significant indication of toxicity in the treated animals, this death was considered by the study authors to be likely not test substance related

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related effects noted on body weights.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related effects noted in haematology or coagulation parameters.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Lower total protein (-5%) and globulin (-9%) levels were recorded as treatment related alterations in serum chemistry parameters in the test substance treated males. The values for the total protein and globulin were within historical control ranges for the laboratory and hence study authors considered the alterations as non-adverse.

Urinalysis findings:

no effects observed

Description (incidence and severity):

There were no test substance-related effects noted in urinalysis parameters.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

One statistically significant difference was observed when the vehicle control and test article-treated groups were compared. Mean thymus relative to final body weight was lower (13.4%) than the vehicle control group in the treated group males but was within the WIL historical control range (version 2.4) for male rats 9-12 and 13-15 weeks of age. This alteration was a function of a slightly lower (but also within the historical control ranges) mean absolute thymus weight and slightly higher mean final body weight in the treated group males and not an effect of test article administration.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

White area(s) were seen in the liver from 1 of 10 males and females in the treated group compared to none in the vehicle control group. These foci correlated to areas of hepatocellular necrosis seen histologically. However, smaller foci of necrosis, that went undetected at necropsy, were seen microscopically in vehicle control group rats, indicating that the white areas and hepatocellular necrosis were incidental changes unrelated to test article administration.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance related effects noted in selected organs and microscopic tissue samples. Minimal to mild acute inflammation of the urinary bladder was observed in 2 of 10 test substance treated females and was considered by the study authors to be related to the administration of the test substance and to be non-adverse. No test substance related microscopic findings were noted on treated skin tissues.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Key result

Dose descriptor:

NOAEL

Effect level:

1 300 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects noted at the dose level of 1300 mg/kg bw/day via dermal route

Critical effects observed:

no

Conclusions:

Repeated dermal application of test substance to rats for 6 hours daily for 28 consecutive days was well-tolerated with no physical observations of toxicity. Evidence of systemic, non-adverse effects attributable to the test article was limited to lower total protein and lower globulin in treated males on study day 28. Although, the microscopic finding of minimal or mild acute inflammation of the urinary bladder observed in 2 treated females is considered to be related to test article administration, it does not appear to be adverse.

Executive summary:

The test article was administered via dermal application to clipped dorsum (approximately 8% of total body surface area) once daily for a minimum of 6 hours per day for 28 consecutive days to 1 group (Group 2) of rats. The application site for each animal was covered with 8-ply gauze, covered with an occluded non-porous latex bandage and held in place with non-irritating tape. Elizabethan collars were applied to restrict access to the wrapped dosing site. The dosage level was 1300 mg/kg/day. A concurrent vehicle control group (Group 1) received the vehicle on a comparable regimen. The dose volume was 1.3 mL/kg for Group 1 and 0.91 mL/kg for Group 2. Each group consisted of 10 animals/sex. Following 28 days of dose administration, all animals were euthanized and necropsied.

 

All animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily, and detailed physical examinations were performed weekly. Application sites were examined once per week at the time of the detailed physical examination and treated and untreated skin was examined macroscopically and microscopically. Individual body weights and food consumption were recorded weekly. Ophthalmic examinations were performed during study weeks -2 and 3. Clinical pathology evaluations (hematology, coagulation, serum chemistry and urinalysis) were performed on all animals on the day of the scheduled necropsy (study day 28). Complete necropsies were conducted on all animals, and selected organs were weighed at the scheduled necropsy. Selected tissues were examined microscopically from all animals.

In the test article-treated group, one male was found dead on study day 13. While the cause of death was undetermined, due to overall lack of significant indications of toxicity in the treated animals, this death was probably not test article-related. There were no test article-related effects on clinical findings, including dermal observations, nor any test article-related effects on body weights, food consumption, hematology, coagulation or urinalysis parameters or organ weights were noted. There were no test article-related macroscopic findings. There were no test article-related microscopic findings on treated skin.

 

Test article-related non-adverse alterations in serum chemistry parameters included lower total protein and glucose levels in the treated males when compared to the vehicle control group. A test article-related but non-adverse microscopic finding was minimal or mild acute inflammation of the urinary bladder observed in 2 treated females.

Repeated dermal application of test substance to rats for 6 hours daily for 28 consecutive days was well-tolerated with no physical observations of toxicity. Evidence of systemic, non-adverse effects attributable to the test article was limited to lower total protein and lower globulin in the treated males on study day 28. Although, the microscopic finding of minimal or mild acute inflammation of the urinary bladder observed in 2 treated females is considered to be related to test article administration, it does not appear to be adverse.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 300 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The database is robust given the number and type of studies available, and consistency of findings

Additional information

7-Day Repeated Oral Exposure:

The test substance in the vehicle, corn oil, was administered orally by gavage once daily for 7 consecutive days to 3 groups (Groups 2-3) of rats. Dosage levels were 100, 300 and 1000 mg/kg/day. A concurrent control group (Group 1) received the vehicle on a comparable regimen. The dose volume was 5 mL/kg for all groups. Each group (Groups 1-4) consisted of 5 animals/sex. Following 7 days of dose administration, all rats were euthanized.

 

All animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily at the time of dosing and approximately 1 and 4 hours post-dosing, and detailed physical examinations were performed weekly. Individual body weight and food consumption were recorded on study days 0 and 7. All carcasses were discarded following examination and collection of gross lesions.

 

All animals survived to the scheduled necropsy. There were no test article-related effects on food consumption and there were no significant macroscopic findings. There were no significant clinical observations in the 100 and 300 mg/kg/day groups.

 

Test article-related clinical observations noted in the 1000 mg/kg/day group as early as study day 0 and throughout the 7-day dosing period included impaired muscle coordination and/or impaired equilibrium in males and females; hypoactivity, decreased respiration rate, and prostration were also noted in females on study day 0. These effects did not persist to the 4-hour post-dose observation on study days 0-6 for males and study days 4-6 for females. These clinical observations were considered adverse, especially since they persisted throughout the 7-day dosing period at approximately 1-hour post-dosing.

 

A test article-related effect on body weight included a trend towards slightly lower body weight gains noted in all test article-treated groups compared to the control group. However, the changes in body weights were not of a magnitude to be considered adverse.

 

Based on the results of this study, adverse toxicity of the test substance administered orally (gavage) to rats for 7 consecutive days was observed at 1000 mg/kg/day as evidenced by clinical observations noted following dosing throughout the 7-day dosing period. The test article was well tolerated in male and female rats at 100 and 300 mg/kg/day.

 

5-Day Repeated Inhalation Exposure:

 

The test substance was administered via nose-only inhalation for 6 hours per day for 5 consecutive days to 3 groups (Groups 2, 3, and 4) of rats. Target exposure concentrations were 42, 84, and 168 ppm for Groups 2, 3, and 4, respectively. A concurrent control group (Group 1) was exposed to filtered air on a comparable regimen. Each group consisted of 5 animals/sex. On the day following the fifth exposure, all animals were euthanized and subjected to necropsy.

 

The animals were observed twice daily for mortality and moribundity. Clinical examinations were performed 3 times daily (prior to exposure, at the approximate exposure midpoint, and approximately 0 to 1 hour following the end of exposure), and detailed physical examinations were performed for randomization and during the exposure phase on study days 0 and 4. Individual body weights and food consumption were recorded at least weekly during the pre-test phase and on study days 0 and 4. Complete necropsies were performed on all animals, and the liver, lungs, and kidneys were weighed at the scheduled necropsy. The kidneys, larynx, liver, lungs, nasal cavity (with turbinates), pharynx, trachea, and urinary bladder were examined microscopically from all animals in the control and 168 ppm group (Groups 1 and 4, respectively). Gross lesions were examined microscopically from all animals (when possible).

 

There were no test substance-related effects on survival or clinical observations. There were no apparent test substance-related effects on body weights, body weight changes, food consumption, organ weights, or macroscopic and microscopic findings at any exposure concentration.

 

Based on the results of this study, exposure of rats to the test substance via 6-hour nose-only inhalation for 5 consecutive days at exposure concentrations ≤168 ppm did not result in any test substance-related effects or dose-limiting toxicity. Therefore, the no-observed-adverse-effect level (NOAEL) for nose-only inhalation exposure of the test substance to rats for 5 consecutive days was 168 ppm, the highest exposure concentration tested.

 

28-Day Repeated Dermal Exposure:

 

The test article was administered via dermal application to clipped dorsum (approximately 8% of total body surface area) once daily for a minimum of 6 hours per day for 28 consecutive days to 1 group (Group 2) of rats. The application site for each animal was covered with 8-ply gauze, covered with an occluded non-porous latex bandage and held in place with non-irritating tape. Elizabethan collars were applied to restrict access to the wrapped dosing site. The dosage level was 1300 mg/kg/day. A concurrent vehicle control group (Group 1) received the vehicle on a comparable regimen. The dose volume was 1.3 mL/kg for Group 1 and 0.91 mL/kg for Group 2. Each group consisted of 10 animals/sex. Following 28 days of dose administration, all animals were euthanized and necropsied.

 

All animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily, and detailed physical examinations were performed weekly. Application sites were examined once per week at the time of the detailed physical examination and treated and untreated skin was examined macroscopically and microscopically. Individual body weights and food consumption were recorded weekly. Ophthalmic examinations were performed during study weeks -2 and 3. Clinical pathology evaluations (hematology, coagulation, serum chemistry and urinalysis) were performed on all animals on the day of the scheduled necropsy (study day 28). Complete necropsies were conducted on all animals, and selected organs were weighed at the scheduled necropsy. Selected tissues were examined microscopically from all animals.

 

In the test article-treated group, one male was found dead on study day 13. While the cause of death was undetermined, due to overall lack of significant indications of toxicity in the treated animals, this death was probably not test article-related. There were no test article-related effects on clinical findings, including dermal observations, nor any test article-related effects on body weights, food consumption, hematology, coagulation or urinalysis parameters or organ weights were noted. There were no test article-related macroscopic findings. There were no test article-related microscopic findings on treated skin.

 

Test article-related non-adverse alterations in serum chemistry parameters included lower total protein and glucose levels in the treated males when compared to the vehicle control group. A test article-related but non-adverse microscopic finding was minimal or mild acute inflammation of the urinary bladder observed in 2 treated females.

 

Repeated dermal application of test substance to rats for 6 hours daily for 28 consecutive days was well-tolerated with no physical observations of toxicity. Evidence of systemic, non-adverse effects attributable to the test article was limited to lower total protein and lower globulin in the treated males on study day 28. Although, the microscopic finding of minimal or mild acute inflammation of the urinary bladder observed in 2 treated females is considered to be related to test article administration, it does not appear to be adverse.

Justification for classification or non-classification

An assessment of the whole database supports the non-classification for STOT RE. The clinical symptoms observed following oral exposure occurred quickly after dosing with 1000 mg/kg bw and were transient in nature. Additionally, there were no test substance-related clinical observations following inhalation of vapours for six hours a day for five consecutive days at a maximum of 168 ppm. Overall, the transient nature of the reported clinical signs at a dosing of 1000 mg/kg bw and consideration of the database as a whole do not fulfil the criteria for STOT RE classification according to European CLP Regulation (EC) No 1272/2008 (as amended).