Hydrocarbon waxes (petroleum), oxidized, Me esters

Endpoint summary

Description of key information

Oral route: No Observed Adverse Effect Level (NOAEL) was considered to be1000 mg/kg bw/day (OECD 407, EU Method B.7, OPPTS 870.3050 and relevant Japanese guidelines).

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 December 2017 to 27 June 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

with no impact on study results or integrity (see below)

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Deviations:

yes

Remarks:

with no impact on study results or integrity (see below)

Qualifier:

according to guideline

Guideline:

other: OPPTS 870.3050 (870.3050 Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Version / remarks:

July 2000

Deviations:

yes

Remarks:

with no impact on study results or integrity (see below)

Qualifier:

according to guideline

Guideline:

other: Japanese Guidelines

Deviations:

yes

Remarks:

with no impact on study results or integrity (see below)

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Remarks:

RccHan:WIST

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST SYSTEM
- A sufficient number of male and female Wistar Han:RccHan:WIST strain rats were obtained from Envigo RMS (UK) Limited, Oxon, UK.
- On receipt the animals were examined for signs of ill-health or injury.
- The animals were acclimatised for eight days during which time their health status was assessed.
- A total of sixty animals (thirty males and thirty females) were accepted into the study.
- At the start of treatment the males weighed 186 to 219g, the females weighed 142 to 167g, and were approximately six weeks old.

ANIMAL CARE AND HUSBANDRY
- The animals were housed in groups of five by sex in solid floor polypropylene cages with stainless steel mesh lids and softwood flake bedding (Datesand Ltd., Cheshire, UK).
- The animals were allowed free access to food and water. A pelleted diet (Rodent 2014C Teklad Global Certified Diet, Envigo RMS (UK) Limited., Oxon, UK) was used. Certificates of analysis of the batches of diet used were appended to the study report.
- Mains drinking water was supplied from polycarbonate bottles attached to the cage.
- Environmental enrichment was provided in the form of wooden chew blocks and cardboard fun tunnels (Datesand Ltd., Cheshire, UK).
- The diet, drinking water, bedding and environmental enrichment were considered not to contain any contaminant at a level that might have affected the purpose or integrity of the study.
- The animals were housed in a single air-conditioned room within the Envigo Research Limited, Shardlow, UK Barrier Maintained Rodent Facility. The rate of air exchange was at least fifteen air changes per hour and the low intensity fluorescent lighting was controlled to give twelve hours continuous light and twelve hours darkness. Environmental conditions were continuously monitored by a computerised system, and print-outs of hourly temperatures and humidities were included in the study records. The Study Plan target ranges for temperature and relative humidity were 22 ± 3 °C and 50 ± 20 % respectively; there were no deviations from these targets.
- The animals were randomized and allocated to dose groups on arrival. Subsequent group mean body weights were checked on Day -1 and animals reallocated where necessary to ensure similarity between the dose groups. The animals were uniquely identified within the study, by an ear punch system routinely used in these laboratories.

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

DOSE ADMINISTRATION
- Animals were allocated to treatment groups as shown in the table below.
- The test item was administered daily, for twenty-eight consecutive days, by gavage using a stainless steel cannula attached to a disposable plastic syringe. Control animals were treated in an identical manner with 4 mL/kg of Arachis oil BP. Recovery group animals were maintained for a further fourteen days treatment-free period following termination of treatment.
- The volume of test and control item administered to each animal was based on the most recent scheduled body weight and was adjusted at weekly intervals.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

TEST ITEM PREPARATION AND ANALYSIS
- For the purpose of this study the test item was prepared at the appropriate concentrations as a solution in Arachis oil BP. The stability and homogeneity of the test item formulations were determined by Envigo Research Limited, Shardlow, UK, Analytical Services. Results showed the formulations to be stable for at least thirty-one days. Formulations were therefore prepared twice during the treatment period and stored at approximately 4 ºC in the dark.
- Samples of each test item formulation were taken and analysed for concentration of at Envigo Research Limited, Shardlow, UK, Analytical Services. The method used for analysis of formulations and the results obtained are given in Annex 2 (attached). The results indicate that the prepared formulations were generally within 4 % of the nominal concentration. However, on one occasion the analytical results were late being made available and as such animals were dosed with formulations which were slightly lower than the ideal specification. Low and intermediate animals were dosed with these for four days whereas high dose animals were dosed for a total of two days - see Deviations to Study Plan.

Duration of treatment / exposure:

28 days

Frequency of treatment:

Once daily

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

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

No. of animals per sex per dose:

Five males and five females

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS
- All animals were examined for overt signs of toxicity, ill-health or behavioural change immediately before dosing, up to thirty minutes post dosing and one hour after dosing during the working week and weekends.
- During the treatment-free period, animals were observed daily. All observations were recorded.

BODY WEIGHT
- Individual body weights were recorded prior to dosing on Day 1 and at weekly intervals thereafter.
- Body weights were also performed prior to terminal kill and, in the case of recovery group animals, on Days 36 and 43 prior to terminal kill.
FOOD CONSUMPTION
- Food consumption was recorded for each cage group at weekly intervals throughout the study.
- Food conversion efficiency was calculated retrospectively.

WATER CONSUMPTION
- Water intake was measured and recorded daily for each cage group.

FUNCTION OBSERVATIONS
- Prior to the start of treatment and on Days 7, 14, 21 and 26, all animals (non-recovery) were observed for signs of functional/behavioural toxicity.
- Functional performance tests were also performed on all animals during Week 4, together with an assessment of sensory reactivity to different stimuli.
- Observations were carried out from approximately two hours after dosing on each occasion.

BEHAVIOURAL ASSESSMENT
- Detailed individual clinical observations were performed for each animal using a purpose built arena.
- The parameters listed in the table below were evaluated.
- The test was developed from the methods used by Irwin (1968) and Moser et al (1988). The scoring system used is outlined in The Key to Scoring System and Explanation for Behavioral Assessments and Sensory Reactivity Tests (attached).

FUNCTIONAL PERFORMANCE TESTS
- Motor Activity: Twenty purpose built 44 infra-red beam automated activity monitors were used to assess motor activity. Animals of one sex were tested at each occasion and were randomly allocated to the activity monitors. The tests were performed at approximately the same time each occasion (at least two hours after dosing), under similar laboratory conditions. The evaluation period was one hour for each animal. The time in seconds each animal was active and mobile was recorded for the overall one hour period and also during the final 20 % of the period (considered to be the asymptotic period, Reiter and Macphail 1979).
- Forelimb/Hindlimb Grip Strength: An automated grip strength meter was used. Each animal was allowed to grip the proximal metal bar of the meter with its forepaws. The animal was pulled by the base of the tail until its grip was broken. The animal was drawn along the trough of the meter by the tail until its hind paws gripped the distal metal bar. A record of the force required to break the grip for each animal was made. Three consecutive trials were performed for each animal. The assessment was developed from the method employed by Meyer et al (1979).

SENSORY REACTIVITY
- The parameters listed in the table below were evaluated.

IN-LIFE SAMPLING AND ANALYSIS
- Hematological and blood chemical investigations were performed on all non-recovery test and control group animals at the end of the treatment period (Day 28) and on all recovery group animals at the end of the treatment-free period (Day 42).
- Blood samples were obtained from the lateral tail vein.
- Where necessary repeat samples were obtained by cardiac puncture prior to necropsy on Days 29 and 43.
- Animals were not fasted prior to sampling.
- Urinalytical investigations were performed on all non-recovery test and control group animals during Week 4 and on all recovery group animals during Week 6. Urine samples were collected overnight by housing the rats in metabolism cages. Animals were maintained under conditions of normal hydration during collection but without access to food.

HEMATOLOGY
- The parameters listed in the table below were evaluated.

BLOOD CHEMISTRY
- The parameters listed in the table below were measured on plasma from blood collected into tubes containing lithium heparin anti-coagulant.

URINALYSIS
- The parameters listed in the table below were evaluated.

ORGAN WEIGHTS
- The organs listed in the table below were removed from animals that were killed either at the end of the dosing period or at the end of the treatment-free period.
- Organs were dissected free from fat and weighed before fixation.

HISTOPATHOLOGY
- Samples of tissues listed in the table below were removed from all animals and, except where stated, preserved in buffered 10% formalin.
- All tissues were dispatched to the histology processing Test Site (Propath UK Ltd) for processing (Principal Investigator: N Lewis).

Sacrifice and pathology:

NECROPSY
- On completion of the dosing period, or in the case of recovery group animals, at the end of the treatment-free period, all animals were killed by intravenous overdose of a suitable barbiturate followed by exsanguination.
- All animals were subjected to a full external and internal examination, and any macroscopic abnormalities were recorded.

PATHOLOGY
- Microscopic examination was conducted by the Study Pathologist (W Henderson).
- A peer review of the findings observed was conducted by Vasanthi Mowat at Envigo CRS Limited, Woolley Road, Alconbury, Huntingdon, Cambridgeshire, PE28 4HS.
- A complete histopathology phase report was appended to the full study report and represented the consensus view of both pathologists.

Other examinations:

THYROID HORMONE ASSESSMENT
- At termination, blood samples were taken from the exsanguination procedure and the plasma from each animal was stored frozen at below -60 °C.
- No treatment-related effects on the pituitary-thyroid axis were identified, therefore these samples were discarded.

Statistics:

See below

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

- There were no clinical signs noted during the study that could be specifically related to systemic toxicity of the test item.
- During the treatment period, sporadic instances of increased salivation were observed for animals of either sex treated with 1000 mg/kg bw/day, this was noted from Day 6 to Day 26 in males and from Day 13 to Day 27 in females, this observation was noted much more prevalently in the male animals. This observation was also noted in two male animals treated with 700 mg/kg bw/day but for one day only. This type of observation is commonly observed in this type of study and is generally considered to be due to an irritant/unpalatable nature of the test item and/or formulation. As such, this observation is considered not to be specifically related to systemic toxicity of the test item.
- There were no clinical signs for females receiving 700 mg/kg bw/day or in any animal receiving 350 mg/kg bw/day.
- No clinical signs were apparent in any animal during the treatment-free period.

Mortality:

no mortality observed

Description (incidence):

- There were no unscheduled deaths during the study.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

- During the treatment period, there was considered to be no treatment-related changes in body weight development for animals of either sex at any dose level.
- Male animals treated with 350 or 700 mg/kg bw/day exhibited slight reductions in body weight gains during the final week of the treatment period which did not achieve statistical significance, a dose relationship was also not apparent. As no such effects were noted in male animals treated with 1000 mg/kg bw/day these reductions in body weight gains were considered to be due to normal biological variation and unrelated to treatment with the test item.
- Females treated with 350 mg/kg bw/day exhibited slight reductions in body weight gain during the second and third weeks of the treatment period which did not achieve statistical significance. Body weight gains were comparable to controls during the final week of the treatment period. As no such effects were noted in female animals treated with 700 or 1000 mg/kg bw/day these reductions in body weight gains were considered to be due to normal biological variation and unrelated to treatment with the test item.
- During the treatment-free period, there were no treatment-related changes in body weight development for animals of either sex.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

- During the treatment or treatment-free period, there was no effect of treatment on food consumption for animals of either sex at any dose level.

Food efficiency:

no effects observed

Description (incidence and severity):

- During the treatment or treatment-free period, there was no effect of treatment on food efficiency for animals of either sex at any dose level.

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

effects observed, non-treatment-related

Description (incidence and severity):

- Gravimetric measurement of water consumption during treatment did not show any obvious effect of treatment at any dose level. There was a suggestion of increased water consumption in male animals treated with 1000 mg/kg bw/day, however, as these animals were putting on more weight than controls and were consequently bigger animals at the end of treatment this was considered to be due to normal biological variation.
- During the treatment-free period male animals previously treated with 1000 mg/kg bw/day continued to show an increase in water consumption when compared to control, again, this was considered to be due to normal biological variation.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

- No toxicologically significant effects were detected in the haematological parameters examined at the end of the treatment or treatment-free periods.
- At the end of the treatment period, males from all dose levels exhibited statistically significant higher (p < 0.05) mean corpuscular volume and statistically significant lower (p < 0.05) mean corpuscular haemoglobin concentrations. A dose relationship was not apparent for either of these two parameters. Two values for mean corpuscular volume from males treated with 700 mg/kg bw/day were lower than the historical control data ranges. Three control values for mean corpuscular haemoglobin concentrations were higher than the historical control data ranges, all treated males exhibited values for mean corpuscular haemoglobin that were within the normal ranges. As the increases exhibited by control animals would have overemphasised the apparent reduction in treated males in relation to mean corpuscular haemoglobin and there were no histopathological correlates for either of these parameters these findings were considered to be incidental and of no toxicological significance.
- Male animals treated with 700 or 1000 mg/kg bw/day also exhibited statistically significant reductions (p < 0.05) in clotting time with a dose relationship being apparent. However, as all individual values were within the historical control data range and there were no histopathological correlates these findings were considered to be incidental and of no toxicological significance.
- Male animals treated with 700 or 1000 mg/kg bw/day and all treated females exhibited statistically significantly increases (p < 0.01) in reticulocyte counts when compared to control with a dose relationship being apparent. With the exception of one female animal treated with 700 mg/kg bw/day which exhibited a value which was slightly higher and one control male animal which exhibited a value that was lower. All values were found to be within the historical control data ranges, as there were no histopathological correlates these findings were considered to be incidental and of no toxicological significance.
- At the end of the treatment-free period males and females previously treated with 1000 mg/kg bw/day exhibited statistically significant increases (p < 0.05-0.01) in reticulocyte counts when compared to control. As all values were found to be within the historical control data ranges and there were no histopathological correlates these findings were considered to be incidental and of no toxicological significance.
- Male animals previously treated with 1000 mg/kg bw/day also exhibited a statistically significant increase (p < 0.01) in eosinophils. With the exception of one value which was higher than the historical control data range all other values were found to be within the expected parameters. As there were no histopathological correlates these findings were considered to be incidental and of no toxicological significance.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

- No toxicologically significant effects were detected in the blood chemical parameters examined at the end of the treatment or treatment-free periods.
- At the end of the treatment period, at all dose levels, females showed statistically significant increases (p<0.05) in chloride concentration when compared with controls. A true dose relationship was not apparent, however, there was no correlation with males. With the exception of one value from animals treated with 350 mg/kg bw/day which was lower, all individual values from test-item treated and control females were within historical control data ranges. As there were no histopathological correlates these findings were considered to be incidental and of no toxicological significance.
- Females treated with 1000 mg/kg bw/day exhibited a statistically significant increase (p < 0.05) in potassium when compared with controls at the end of the treatment period. Whilst it appears that a dose relationship within treated groups was evident, it is considered that a true dose-relationship was not apparent as the two lower test groups actually had mean potassium values which were lower than control. Two control and four values for animals treated with 1000 mg/kg bw/day were higher than the historical control data ranges. As there were no histopathological correlates these findings were considered to be incidental and of no toxicological significance.
- No statistically significant findings were noted for male animals at the end of the treatment period.
- At the end of the treatment-free period, group mean aspartate aminotransferase in males previously treated with 1000 mg/kg bw/day were statistically significantly reduced (p<0.05) when compared to controls. All values were found to be within the normal historical data ranges.
- No statistically significant findings were noted for female animals at the end of the treatment-free
period.

Urinalysis findings:

effects observed, non-treatment-related

Description (incidence and severity):

- There were considered to be no treatment-related effects detected in the urinalytical parameters examined.
- At the end of the treatment period male animals treated with 700 mg/kg bw/day exhibited a statistically significant increase (p < 0.05) in specific gravity. However, all values were within the historical control data range, as similar findings were not apparent at 1000 mg/kg bw/day and the value that attained significance was lower than the values achieved at 350 mg/kg bw/day (which did not attain significance) this finding was considered to be incidental and of no toxicological significance.
- At the end of the treatment-free period there were no statistically significant effects detected in the urinalytical parameters examined.

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

- There were no treatment-related changes in the behavioural parameters measured.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

- There were no toxicologically significant effects detected in the organ weights measured at the end of the treatment or treatment-free periods.
- At the end of the treatment period, male animals from all treatment groups exhibited statistically significant decreases (p<0.05) in absolute and relative to terminal body weight related prostate and seminal vesicles (with Coagulating Gland) weights, a dose relationship was apparent. One absolute value for animals treated with 700 mg/kg bw/day was lower than the historical control data range, all other values were within these ranges. Relative values for two control and one value for animals treated with 350 mg/kg bw/day were higher than the historical control data range and one value was lower than the historical control data range for animals treated with 700 mg/kg bw/day. All relative values for animals treated with 1000 mg/kg bw/day were within the historical control data ranges. As there were no histopathological correlates these findings were considered to be incidental and unrelated to treatment with the test item.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

NECROPSY
- With the exception of one control male which exhibited a pale pituitary, no macroscopic abnormalities were detected at the end of the treatment period.
- At the end of the treatment free period, one male animal previously treated with 1000 mg/kg bw/day exhibited a mass on the right epididymis, no macroscopic abnormalities were detected in any other animal. Due to the isolated nature of this finding it was considered to be unrelated to treatment with the test item.

Neuropathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

FUNCTIONAL PERFORMANCE TESTS
- There were considered to be no treatment-related changes in functional performance at any
dose level.
- Females treated with the test item at 700 and 1000 mg/kg bw/day showed statistically significant increases (p < 0.05) in hind limb grip strength (test 3). As the increase in hind limb grip strength was only noted in one out of the three runs completed, there were no clinical signs observed to signify a neurotoxic effect of the test item and a dose relationship was not apparent, these incidences were considered to be incidental and of no toxicological relevance.

SENSORY REACTIVITY ASSESSMENTS
- There were no treatment-related changes detected at any dose level.

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

- No changes were noted which could be attributed to the administration of the test item.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Key result

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: no toxicologically significant changes in animals of either sex at any dose level.

Critical effects observed:

no

Conclusions:

Oral administration of the test item to rats for a period of twenty-eight consecutive days followed by a fourteen-day recovery period at dose levels of up to 1000 mg/kg bw/day did not result in any toxicologically significant changes in animals of either sex at any dose level. Whilst the findings cannot be unequivocally ruled out as being treatment related, there was no evidence to suggest that these were adverse events especially as the majority of individual values were found to be within the historical control data ranges, hence No Observed Adverse Effect Level (NOAEL) is the appropriate terminology and was considered to be 1000 mg/kg bw/day.

Executive summary:

GUIDELINE

The study was designed to investigate the systemic toxicity of the test item and was compatible with OECD Guidelines for Testing of Chemicals No. 407 "Repeated Dose 28 Day Oral Toxicity Study in Rodents" (adopted 03 October 2008), Commission Directive 96/54/EC (Method B7), USA Environmental Protection Agency (EPA) Health Effects Test Guidelines, OPPTS 870.3050 Repeated Dose 28-Day Oral Toxicity Study in Rodents (July 2000) and The Japanese Ministry of Economy Trade and Industry (METI), Ministry of Health, Labor and Welfare (MHLW) and Ministry of the Environment (MOE) Guidelines of 21 November 2003 for a twenty-eight day repeat dose oral toxicity study as required by the Law Concerning the Evaluation of Chemical Substances and Regulation of their Manufacture, etc (Chemical Substance Control Law) 1973 of Ministry of International Trade and Industry (MITI) amended 2004.

 

METHODS

The test item was administered by gavage to three groups, each of five male and five female Wistar Han:RccHan:WIST strain rats, for twenty-eight consecutive days, at dose levels of 350, 700 and 1000 mg/kg bw/day. A control group of five males and five females was dosed with vehicle alone (Arachis oil BP). Two recovery groups, each of five males and five females, were treated with the high dose (1000 mg/kg bw/day) or the vehicle alone for twenty-eight consecutive days and then maintained without treatment for a further fourteen days. Clinical signs, body weight change, food and water consumption were monitored during the study. Hematology, blood chemistry and urinalysis were evaluated for all non-recovery group animals at the end of the treatment period and for all recovery group animals at the end of the treatment-free period. All animals were subjected to gross necropsy examination and histopathological examination of selected tissues was performed.

 

RESULTS

Mortality: There were no unscheduled deaths during the study.

Clinical observations: There were no clinical signs noted during the study that could be specifically related to systemic toxicity of the test item.

Behavioural assessment: There were no treatment-related changes in the parameters measured.

Functional Performance Tests: There were considered to be no treatment-related changes in functional performance at any dose level.

Sensory reactivity assessments: There were no treatment-related changes detected at any dose level.

Body weight: During the treatment period, there were no treatment-related changes in body weight development for animals of either sex at any dose level.

During the treatment-free period, there were no treatment-related changes in body weight development for animals of either sex.

Food consumption: During the treatment or treatment-free period, there was no effect of treatmenton foodconsumption or food efficiency for animals of either sex at any dose level.

Water Consumption: Gravimetric measurement of water consumption during treatment did notshow any obviouseffect of treatment at any dose level.

Hematology: No toxicologically significant effects were detected in the parametersexamined at the end of the treatment or treatment-free periods.

Blood Chemistry: No toxicologically significant effects were detected in the parametersexamined at the end of the treatment or treatment-free periods.

Urinalysis: Evaluations at the end of the treatment or treatment-free periods did notidentifyany effects of toxicological importance in males or females receiving the test item up to adose level of 1000 mg/kg bw/day.

Necropsy: There were no treatment-related macroscopic abnormalities detected.

Organ Weights: There were no toxicologically significant effects detected in the organ weightsmeasured atthe end of the treatment or treatment-free periods.

Histopathology: No changes were noted which could be attributed to the administration of the testitem.

 

CONCLUSION

Oral administration of the test item to rats for a period of twenty-eight consecutive days followed by a fourteen-day recovery period at dose levels of up to 1000 mg/kg bw/day did not result in any toxicologically significant changes in animals of either sex at any dose level. Whilst the findings cannot be unequivocally ruled out as being treatment related, there was no evidence to suggest that these were adverse events especially as the majority of individual values were found to be within the historical control data ranges, hence No Observed Adverse Effect Level (NOAEL) is the appropriate terminology and was considered to be 1000 mg/kg bw/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Oral route

The key study was designed to investigate the systemic toxicity of the test item and was compatible with OECD Guidelines for Testing of Chemicals No. 407 "Repeated Dose 28 DayOral Toxicity Study inRodents" (adopted 03 October 2008), Commission Directive 96/54/EC (Method B7), USAEnvironmental Protection Agency (EPA) Health Effects Test Guidelines,OPPTS 870.3050 Repeated Dose 28-Day Oral Toxicity Study in Rodents (July 2000) and The Japanese Ministry of Economy Tradeand Industry (METI), Ministry of Health,Labor and Welfare (MHLW) and Ministry of the Environment (MOE) Guidelines of21 November 2003 for a twenty-eight day repeat dose oral toxicity study as requiredby the Law Concerning the Evaluation of Chemical Substances and Regulation oftheir Manufacture, etc (Chemical Substance Control Law) 1973 of Ministry ofInternational Trade and Industry (MITI) amended 2004.

The test item was administered by gavage to three groups, each of five male and five female Wistar Han:RccHan:WIST strain rats, for twenty-eight consecutive days, at dose levelsof 350, 700 and 1000 mg/kg bw/day. A control group of five males and five females wasdosed with vehicle alone (Arachis oil BP). Two recovery groups, each of five males and fivefemales, were treated with the high dose (1000 mg/kg bw/day) or the vehicle alone for twenty-eight consecutive days and then maintained without treatment for a further fourteen days.Clinical signs, body weight change, food and water consumption were monitored during the study. Hematology, blood chemistry and urinalysis were evaluated for all non-recoverygroup animals at the end of the treatment period and for all recoverygroup animals at the end of the treatment-free period. All animals were subjected to gross necropsy examination and histopathological examination of selected tissues was performed.

Mortality: There were no unscheduled deaths during the study.

Clinical observations: There were no clinical signs noted during the study that could be specifically related to systemic toxicity of the test item.

Behavioral Assessment: There were no treatment-related changes in the parameters measured.

Functional Performance Tests: There were considered to be no treatment-related changes in functional performance at any dose level.

Sensory Reactivity Assessments: There were no treatment-related changes detected at any dose level.

Body Weight: During the treatment period, there were no treatment-related changes in body weight development for animals of either sex at any dose level. During the treatment-free period, there were no treatment-related changes in body weight development for animals of either sex.

Food Consumption: During the treatment or treatment-free period, there was no effect of treatmenton foodconsumption or food efficiency for animals of either sex at any dose level.

Water Consumption: Gravimetric measurement of water consumption during treatment did notshow any obvious effect of treatment at any dose level.

Hematology: No toxicologically significant effects were detected in the parametersexamined at the end of the treatment or treatment-free periods.

Blood Chemistry: No toxicologically significant effects were detected in the parametersexamined at the end of the treatment or treatment-free periods.

Urinalysis: Evaluations at the end of the treatment or treatment-free periods did not identify any effects of toxicological importance in males or females receiving the test item up to adose level of 1000 mg/kg bw/day.

Necropsy: There were no treatment-related macroscopic abnormalities detected.

Organ Weights: There were no toxicologically significant effects detected in the organ weights measured at the end of the treatment or treatment-free periods.

Histopathology: No changes were noted which could be attributed to the administration of the test item.

Oral administration of the test item to rats for a period of twenty-eight consecutive days followed by a fourteen-day recovery period at dose levels of up to 1000 mg/kg bw/day did not result in any toxicologically significant changes in animals of either sex at any dose level. Whilst the findings cannot be unequivocally ruled out as being treatment related, there was no evidence to suggest that these were adverse events especially as the majority of individual values were found to be within the historical control data ranges, hence No Observed Adverse Effect Level (NOAEL) is the appropriate terminology and was considered to be 1000 mg/kg bw/day.

Inhalation route

The test substance has been shown to have a low vapour pressure (1.91 Pa at 25 °C) and high onset boiling point (decomposition from approximately 183 °C at 98 kPa). As a result, the potential for generation of inhalable forms of the substance is low and exposure of humans via the respiratory route is predicted to be low under general use conditions. Furthermore, the Log Pow value of > 10.0 does not favour absorption directly across the respiratory tract epithelium by passive diffusion (Log10 Pow > 4) and the substance will not be readily soluble in blood (water solubility determined to be 4.34 x 10E-03 gTOC/L at 20 °C). Thus experimental evidence is in agreement with ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7c: Endpoint specific guidance (Version 3.0; June 2017), and investigation of repeated dose toxicity via the inhalation route is scientifically invalid.

Dermal route

The substance is a paste that is non-toxic via the oral route under acute conditions (LD50 > 2000 mg/kg) and repeated exposure of the skin is not expected under normal condition of use. In addition, the test material has been determined to have a low vapour pressure (1.91 Pa at 25 °C) and high onset boiling point range (decomposition from approximately 183 °C at 101 kPa). These data indicate that the potential for dermal absorption after exposure to vapour is low under general use conditions at ambient temperature. Furthermore, the substance is a UVCB with a relatively high molecular weight, is highly insoluble in water (4.34 x 10E-03 gTOC/L at 20.0 ± 0.5 °C) and has a Log10 Kow value of > 10.0. Consequently, and in accordance with ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7c: Endpoint specific guidance (Version 3.0; June 2017), the substance is considered insufficiently soluble to partition from the stratum corneum into the epidermis and the majority of UVCB constituents are likely to be too large to favour dermal absorption (molecular weight > 100 g/moL and log10 Pow > 4). Investigation of repeated dose toxicity via the dermal route is therefore contraindicated.

Justification for classification or non-classification

No treatment-related effects were reported in a 28-day oral investigation at dose levels of 350, 700 and 1000 mg/kg bw (OECD 407) or 350, 700 and 1000 mg/kg bw during reproductive/developmental toxicity screening via the oral route (OECD 421). Classification for Specific Target Organ Toxicity (STOT RE category 1 or 2) is therefore not required under the terms of Regulation (EC) No 1272/2008 and subsequent amendments.