Ethyl formate

Endpoint summary

Description of key information

Repeated dose oral

NOAEL was considered to be 500 mg/kg body weight/day when Osborne-Mendel male and female rats treated with test substance for 17 week by oral feed.

Repeated dose inhalation toxicity:

In a Repeated dose inhalation toxicity study, Sprague-Dawley male and female rats were inhaled with test substance in the concentration of 0, 0.2, 1 and 4 mg/L for 6 hr/day, 5 days by Whole body exposure for 90 days. Decrease in locomotor activity of the male and female rats were observed as compared to control, but recovered after the exposure ended at 4 mg/L. No mortality was observed during the study in treated rats as compared to control. Body weight gain significantly decreased in male and female rats from week 1 were observed as compared to control rats. Increased body weight gain on week 4 were observed in male rat as compared to control at 4 mg/L and increased body weight gain on week 4 in male rats were observed as compared to control at 1 mg/L. The increased body weight of the male rats exposed to 330 ppm at week 4 was not considered to be ethyl formate-related change because they were isolated changes. Significantly decreased in male and female rat were observed from week 1 and week 3, respectively as compared to control at 4 mg/L. Similarly, increased HGB and HCT level in male and decreased in Reti level n female rat were observed as compared to control and Ca and TG levels decreased in male and female rats respectively at 4 mg/L. Increase in Ketone body in male and female rat and Urobilinogen level in female rat were observed as compared to control. Increase in Ketone body in female rat were observed as compared to control at 1 mg/L. Reduced body weight and food consumption are occasionally accompanied by increase in urinary ketone levels, because energy metabolism under those conditions shifts from gluconeogenesis to incomplete oxidation of fatty acids. In addition, absolute and relative adrenal weight increased in male and female rats and relative brain, kidney, and lung in male and female rat as compared to control and Absolute or relative thymus weight or both decreased in male and female rats and absolute heart, kidney, liver, lung, and spleen weights decreased as compared to control at 4 mg/L. Degeneration, Squamous metaplasia and Lesions were mainly noted in the dorsal meatus and occasionally in the septum and turbinate in male and female rats as compared to control at 4 mg/L. Therefore, NOAEC was considered to 1 mg/L when Sprague-Dawley male and female rats were inhaled with ethyl formate for 90 days.

Repeated dose dermal toxicity:

10 weeks repeated dermal study was conducted on male “s” strain mice with the dose concentration of 2760 mg/kg bw/day (0.3ml in acetone applied) and the histopathologic analysis is done to determine the toxic effects. No significant activity was observed In terms of epidermal hyperplasia. Therefore, NOAEL was considered to be 2760 mg/kg bw/day when male “s” strain mice were treated for 10 weeks.

Key value for chemical safety assessment

Toxic effect type:

concentration-driven

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

Data is from peer-reviewed journal

Qualifier:

according to guideline

Guideline:

other: as below

Principles of method if other than guideline:

Subacute repeated toxicity study of test substance orally in rats

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Osborne-Mendel

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data available
- Age at study initiation: No data available
- Weight at study initiation: No data available
- Fasting period before study: No data available
- Housing: Housed individually in wire cages.
- Diet (e.g. ad libitum): food ad libitum
- Water (e.g. ad libitum): water ad libitum
- Acclimation period:No data available

ENVIRONMENTAL CONDITIONS
No data available

Route of administration:

oral: feed

Vehicle:

other: Diet

Details on oral exposure:

Details on oral exposure
PREPARATION OF DOSING SOLUTIONS: Fresh diets were made by mixing test substance.

DIET PREPARATION
- Rate of preparation of diet (frequency): Weekly
- Mixing appropriate amounts with (Type of food): No data available
- Storage temperature of food: No data available

VEHICLE
- Justification for use and choice of vehicle (if other than water): Rat diet were used
- Concentration in vehicle: 0, 1000, 2500 and 10,000 ppm
- Amount of vehicle (if gavage): No data available
- Lot/batch no. (if required): No data available
- Purity: No data available

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

17 weeks

Frequency of treatment:

Daily

Dose / conc.:

0 other: mg/kg-bw/day

Remarks:

0 ppm

Dose / conc.:

50 other: mg/kg-bw/day

Remarks:

1000 ppm

Dose / conc.:

125 other: mg/kg-bw/day

Remarks:

2500 ppm

Dose / conc.:

500 other: mg/kg-bw/day

Remarks:

10000 ppm

No. of animals per sex per dose:

Total: 80
0 ppm: 10 male and 10 female
50 ppm: 10 male and 10 female
125 ppm: 10 male and 10 female
500 ppm: 10 male and 10 female

Control animals:

yes, concurrent vehicle

Details on study design:

Details on study design
- Dose selection rationale: No data available
- Rationale for animal assignment (if not random): Animals were randomized by weight (every level having animals of equal weight).
- Rationale for selecting satellite groups: No data available
- Post-exposure recovery period in satellite groups: No data available
- Section schedule rationale (if not random): No data available

Observations and examinations performed and frequency:

Observations and examinations performed & frequency
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: No data available
- Cage side observations checked in table [No.?] were included: Mortality was observed.

DETAILED CLINICAL OBSERVATIONS: Yes
–Time schedule: Weekly

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data available.

FOOD EFFICIENCY:
No data available
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data available

OPHTHALMOSCOPIC EXAMINATION: No data available

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At termination.
- Anaesthetic used for blood collection: No data available.
- Animals fasted: No data available.
- How many animals: No data available.
- Parameters checked in table [No.?] were examined: White cell counts, red cell counts, hemoglobin and haematocrits were examined.

CLINICAL CHEMISTRY: No data available

URINALYSIS: No data available

NEUROBEHAVIOURAL EXAMINATION: No data available

OTHER:
Organ weight: Yes

Organs weighted:
Liver, kidneys, spleen, heart and testes were weighed.

Sacrifice and pathology:

Sacrifice and pathology
GROSS PATHOLOGY: Yes, Necropsied with the process of exsanguinean.

Abnormalities, gross changes and the suspected reason for death were noted.

HISTOPATHOLOGY: Yes,
Organs were preserved in 10% buffered formalin-saline solution for histopathological examination. For routine histopathology, sections were embedded in paraffin wax and stained with haematoxylin and eosin.

A detailed microscopic examination in the study was done on 6 or 8 rats, evenly divided by sex, from the high dose group and the control group. If changes attributable to the test compound were found in the high dose group, additional animals on lower dosage levels were examined as indicated. So microscopic examination was not performed for 1000 and 2500 ppm dose level.

Organs examined: Liver, kidneys, spleen, heart, testes, and thoracic viscera, one hind leg, for bone, bone marrow and muscle were examined.

Other examinations:

No data available

Statistics:

No data available

Clinical signs:

no effects observed

Description (incidence and severity):

No effect were observed on growth of treated rat as compared to control.

Mortality:

no mortality observed

Description (incidence):

No effect on survival were observed in treated rat as compared to control.

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Description (incidence and severity):

No effect were observed on hematological parameters of treated rat as compared to control.

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

No gross pathological abnormalities were observed in treated rat as compared to control.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

No microscopic changes in the tissues were observed in treated rat as compared to control.

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Details on results:

Pathological changes attributable to disease or age have not been included.

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical signs

gross pathology

haematology

histopathology: non-neoplastic

mortality

Remarks on result:

other: No effect observed

Critical effects observed:

not specified

Conclusions:

NOAEL was considered to be 500 mg/kg body weight/day when Osborne-Mendel male and female rats treated with tes substance for 17 week by oral feed.

Executive summary:

In a Chronic repeated dose oral toxicity study, Osborne-Mendel male and female rats treated with test substance in the concentrations of50, 125 and 500mg/kg bw orally in diet. The animals were observed for clinical sign, body weight, food consumption, Hematology, gross and Histopathology. Results show that no effect was observed on survival and growth of all the treated rats. Similarly, no effect was observed on hematological parameters of treated rat as compared to control. In addition, No gross pathological abnormalities and microscopic changes in the tissues were observed in all treated rat as compared to control. Therefore, NOAEL was considered to be 500 mg/kg body weight/day when Osborne-Mendel male and female rats treated with test substance for 17 weeks by oral feed.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

500 mg/kg bw/day

Study duration:

chronic

Species:

rat

Quality of whole database:

Data is Klimisch 2 and from publication

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Justification for type of information:

Data is from publication

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Principles of method if other than guideline:

Repeated dose inhalation toxicity study of Ethyl Formate in Rats

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Japan SLC., Inc. (Hamamatsu, Japan) via Joongang Experimental Animal Co., Ltd. (Seoul, Korea)
- Age at study initiation: 7 weeks
- Weight at study initiation:
- Fasting period before study:
- Housing: Animals were housed individually in wire-bottomed stainless-steel mesh cages placed in exposure
Chambers.
- Diet (e.g. ad libitum): Commercial
rodent chow (PicoLab Rodent Diet 5053, LabDiet, USA) ad libitum, ad libitum
- Water (e.g. ad libitum): sterilized tap water, ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 50 ± 20%
- Air changes (per hr): 12-15 air changes/hr
- Photoperiod (hrs dark / hrs light): artificial lighting from 08:00 to 20:00

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Whole-body
exposure chambers (WITC-00-M, HCT Co., Korea)
- Method of holding animals in test chamber: Whole-body
- Source and rate of air:
- Method of conditioning air:
- System of generating particulates/aerosols: LVg-04-A
- Temperature, humidity, pressure in air chamber:23 °C
- Air flow rate:
- Air change rate:
- Method of particle size determination:
- Treatment of exhaust air:

TEST ATMOSPHERE
- Brief description of analytical method used: The ethyl formate levels were detected using gas chromatography (TRACE1310,
Thermo Scientific, China) with the following apparatus: detector, flame ionization detector; column, TraceGold TG- 5MS 5% diphenyl-95% dimethyl polysiloxane capillary column (30 m length, 0.25 mm i.d., 0.25 mm film thickness).
- Samples taken from breathing zone: yes

VEHICLE (if applicable)
- Justification for use and choice of vehicle: fresh air
- Composition of vehicle:
- Type and concentration of dispersant aid (if powder):
- Concentration of test material in vehicle: 0, 66, 330, and 1,320 ppm
- Lot/batch no. of vehicle (if required):
- Purity of vehicle:

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

using gas chromatography

Duration of treatment / exposure:

90 days

Frequency of treatment:

6 hr/day, 5 days

Dose / conc.:

0 mg/L air (analytical)

Dose / conc.:

0.2 mg/L air (analytical)

Dose / conc.:

1 mg/L air (analytical)

Dose / conc.:

4 mg/L air (analytical)

No. of animals per sex per dose:

Total: 80
0 mg/L : 10 male, 10 female
0.2 mg/L : 10 male, 10 female
1 mg/L : 10 male, 10 female
4 mg/L : 10 male, 10 female

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Concentrations of 0, 0.2, 1 and 4 mg/L was selected based on a prior study and the OEL.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Before, during, and after the exposure period
- Cage side observations checked in table [No.?] were included.: Mortality were observed.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Before, during, and after the exposure period

BODY WEIGHT: Yes
- Time schedule for examinations: All the rats were weighed individually on the first exposure day and once a week after that.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

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

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes / No / No data
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: On week 12.
- Dose groups that were examined: All doses were examined.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: On day 90 of treatment.
- Anaesthetic used for blood collection: Yes, isoflurane
- Animals fasted: Yes, overnight
- How many animals: All 80 animals were examined.
- Parameters checked in table [No.?] were examined.: Prothrombin time (PT)
and activated partial thromboplastin time (APTT), total red blood cell (RBC) count, hemoglobin (HGB) concentration, hematocrit (HCT), mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), platelet (PLT) count, total white blood cell (WBC) count, differential WBC count (neutrophil, lymphocyte, monocyte, eosinophil, and basophil), reticulocyte (Reti) count, PT, and APTT were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: On day 90 of treatment.
- Animals fasted: Yes, overnight
- How many animals: All 80 animals were examined.
- Parameters checked in table [No.?] were examined.: Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), blood urea nitrogen
(BUN), creatinine (Crea), total bilirubin (T-Bili), total protein (TP), albumin (Alb), A/G ratio, total cholesterol (TChol), triglyceride (TG), glucose (Glu), potassium (K), calcium (Ca), chloride (Cl), inorganic phosphorus (P), and sodium (Na) were examined.

URINALYSIS: Yes
- Time schedule for collection of urine: on week 13
- Metabolism cages used for collection of urine: Yes / No / No data
- Animals fasted: Yes / No / No data
- Parameters checked in table [No.?] were examined.: pH, protein, glucose, ketone body, bilirubin, occult blood, leukocyte, nitrite, urobilinogen, and specific gravity were examined.

NEUROBEHAVIOURAL EXAMINATION: No data
- Time schedule for examinations:
- Dose groups that were examined:
- Battery of functions tested: sensory activity / grip strength / motor activity / other:

OTHER:
Organ weight:
Absolute and relative adrenals, brain, heart, kidneys, liver, spleen, testes, thymus, epididymides, lung, thyroids, ovaries, and uterus weight were examined.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
External body surfaces and all orifices were examined.

HISTOPATHOLOGY: Yes
Organ/tissues were preserved in 10% neutral buffered formalin:
Organ examined: adrenals, aorta, bone
marrow, brain, cecum, colon, duodenum, epididymides, esophagus, eyes, femur, Harderian glands, heart, ileum, jejunum, kidneys, larynx, liver, lung, lymph nodes (hilar and mesenteric), mammary gland, nasopharyngeal tissue, nerves (optic and sciatic), pancreas, parathyroids, pituitary, prostate, rectum, salivary glands (submandibular, sublingual,
and parotid), seminal vesicles, skeletal muscle, skin, spinal cord (cervical, lumbar, and thoracic), spleen, sternum, stifle joint, stomach, testes, teeth, thymus, thyroids, trachea, urinary bladder, ovaries, and uterus. The eyes/optic nerve and testes were preserved in Davidson’s solution

Statistics:

Statistical analysis was performed for body weight, food consumption, hematology and serum biochemistry parameters, organ weights, and organ/body weight. For the control and ethyl formate-exposed groups, the homogeneity of the variance of numerical data was determined using Levene’s test. Groups with homogenous and heterogeneous data were compared using one-way analysis of variance (ANOVA) and non-parametric Kruskal- Wallis test, respectively. If statistical significance was observed (p < 0.05), Dunnett’s test (for ANOVA) or the Steel test (for Kruskal-Wallis) was used for multiple comparisons of the control group with each dose group.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

when treated with 4 mg/L, decrease in locomotor activity of the male and female rats were observed as compared to control, but recovered after the exposure ended.

Mortality:

no mortality observed

Description (incidence):

No mortality were observed during the study in treated rats as compared to control.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

When treated with 4 mg/L, Body weight gain significantly decreased in male and female rats from week 1 were observed as compared to control rats. Increased body weight gain on week 4 were observed in male rat as compared to control.

When treated with 1 mg/L, increased body weight gain on week 4 in male rats were observed as compared to control.
The increased body weight of the male rats exposed to 330 ppm at week 4 was
not considered to be ethyl formate-related change because they were isolated changes.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

When treated with 4 mg/L, significantly decreased in male and female rat were observed from week 1 and week 3, respectively as compared to control.

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

When treated with 4 mg/L, increased HGB and HCT level in male and decreased in Reti level n female rat were observed as compared to control.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

When treated with 4 mg/L, Ca and TG levels decreased in male and female rats respectively.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

When treated with 4 mg/L, incerase in Ketone body in male and femlae rat and Urobilinogen level in female rat were observed as compared to control.

When treated with 1 mg/L, incerase in Ketone body in femlae rat were observed as compared to control.
Reduced body weight and food consumption are occasionally accompanied by increase in urinary ketone levels, because energy metabolism under those conditions shifts from gluconeogenesis to incomplete oxidation of fatty acids.

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

When treated with 4 mg/L, absolute and relative adrenal weight increased in male and female rats and relative brain, kidney, and lung in male and female rat as compered to control.
Absolute or relative thymus weight or both decreased in male and female rats and absolute heart, kidney, liver, lung, and spleen weights decreased as compered to control.

Gross pathological findings:

no effects observed

Description (incidence and severity):

All the macroscopic findings of the eye, liver, and ovaries were considered to be incidental and of no toxicological significance.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

When treated with 4 mg/L, Degeneration, Squamous metaplasia and Lesions were mainly noted in the dorsal meatus and occasionally in the septum and turbinate in male and female rats as compared to control.

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Dose descriptor:

NOAEC

Effect level:

1 mg/L air (analytical)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

clinical signs

food consumption and compound intake

gross pathology

haematology

histopathology: non-neoplastic

mortality

organ weights and organ / body weight ratios

urinalysis

Remarks on result:

other: No effect observed

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Conclusions:

NOAEC was considered to 1 mg/L when Sprague-Dawley male and female rats were inhaled with test substance for 90 days.

Executive summary:

In a Repeated dose inhalation toxicity study, Sprague-Dawley male and female rats were inhaled with test substance in the concentration of 0, 0.2, 1 and 4 mg/L for 6 hr/day, 5 days by Whole body exposure for 90 days. Decrease in locomotor activity of the male and female rats were observed as compared to control, but recovered after the exposure ended at 4 mg/L. No mortality was observed during the study in treated rats as compared to control. Body weight gain significantly decreased in male and female rats from week 1 were observed as compared to control rats. Increased body weight gain on week 4 were observed in male rat as compared to control at 4 mg/L and increased body weight gain on week 4 in male rats were observed as compared to control at 1 mg/L. The increased body weight of the male rats exposed to 330 ppm at week 4 was not considered to be ethyl formate-related change because they were isolated changes. Significantly decreased in male and female rat were observed from week 1 and week 3, respectively as compared to control at 4 mg/L. Similarly, increased HGB and HCT level in male and decreased in Reti level n female rat were observed as compared to control and Ca and TG levels decreased in male and female rats respectively at 4 mg/L. Increase in Ketone body in male and female rat and Urobilinogen level in female rat were observed as compared to control. Increase in Ketone body in female rat were observed as compared to control at 1 mg/L. Reduced body weight and food consumption are occasionally accompanied by increase in urinary ketone levels, because energy metabolism under those conditions shifts from gluconeogenesis to incomplete oxidation of fatty acids. In addition, absolute and relative adrenal weight increased in male and female rats and relative brain, kidney, and lung in male and female rat as compared to control and Absolute or relative thymus weight or both decreased in male and female rats and absolute heart, kidney, liver, lung, and spleen weights decreased as compared to control at 4 mg/L. Degeneration, Squamous metaplasia and Lesions were mainly noted in the dorsal meatus and occasionally in the septum and turbinate in male and female rats as compared to control at 4 mg/L. Therefore, NOAEC was considered to 1 mg/L when Sprague-Dawley male and female rats were inhaled with test substance for 90 days.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

1 000 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

The data is K2 level and from publication

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer-reviewed journal

Justification for type of information:

Data is from peer-reviewed journal

Qualifier:

according to guideline

Guideline:

other: as below mentioned

Principles of method if other than guideline:

Subchronic repeated dermal toxicity study was conducted to determine the toxicity of test substance in male mice.

GLP compliance:

not specified

Limit test:

no

Species:

mouse

Strain:

other: Stock albino of the " S " strain

Sex:

male

Details on test animals or test system and environmental conditions:

Details on test animal
- Age at study initiation: 7-9 weeks old.
- Diet :fed on cubes prepared according to the Rowett Institute plus fresh greenstuff twice a week formula
- Water : ad libitum
- Acclimation period:

Type of coverage:

not specified

Vehicle:

other: Acetone

Details on exposure:

Details on dermal exposure
PREPARATION OF DOSING SOLUTIONS:
All solutions were prepared weight per total volume in the solvent. The preparation of glycine ethyl ester from the hydrochloride is described in the experimental section. The podophyllin extract used was prepared from the crude resin by extraction with acetone. Dosage was calculated on the dry weight of the extract after filtration and evaporation.
positive control: croton oil


TEST SITE
- Area of exposure: whole back, from forelimbs to tail.

The hair was clipped from the whole back, from forelimbs to tail, before treatment and at intervals when necessary. Solutions were delivered from calibrated pipettes, care being taken that they spread as evenly as possible over the whole
clipped area. A glass spreader was used for solutions which did not otherwise spread easily.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

10 weeks

Frequency of treatment:

10 weekly applications of 0.3ml neat agent

Dose / conc.:

2 760 mg/kg bw/day

No. of animals per sex per dose:

No data

Control animals:

yes, concurrent vehicle

Details on study design:

No data

Positive control:

No data

Observations and examinations performed and frequency:

No data

Sacrifice and pathology:

HISTOPATHOLOGY: Yes

Other examinations:

No data

Statistics:

No data

Clinical signs:

not specified

Dermal irritation:

not specified

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Specimens of skin from mice additional to each group were removed under ether anaesthesia three days after one and/or two applications of the test substance. Mice which died during or were killed at the end of the tests were examined post mortem for lung adenomata and other abnormalities. Specimens for histological examination were fixed in Zenker's fluid, embedded in paraffin wax, and stained with haematoxylin and eosin-Biebrich scarlet.

Histopathological findings: neoplastic:

not specified

Dose descriptor:

NOEL

Effect level:

2 760 mg/kg bw/day

Based on:

test mat.

Sex:

male

Basis for effect level:

histopathology: non-neoplastic

Remarks on result:

other: No Epidermal hyperplasia observed.

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Conclusions:

NOAEL was considered to be 2760 mg/kg bw/day when male “s” strain mice were treated by test substance for 10 weeks dermally.

Executive summary:

10 weeks repeated dermal study was conducted for test substance on male “s” strain mice with the dose concentration of 2760 mg/kg bw/day (0.3ml in acetone applied) and the histopathologic analysis is done to determine the toxic effects. No significant activity was observed In terms of epidermal hyperplasia. Therefore, NOAEL was considered to be 2760 mg/kg bw/day for test substance when male “s” strain mice were treated for 10 weeks

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

2 760 mg/kg bw/day

Study duration:

subchronic

Species:

mouse

Quality of whole database:

Data is from peer-reviewed journal

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Repeated dose oral toxicity:

Data available for the test chemicals was reviewed to determine the repeated dose oral toxicity of the test chemical Ethyl formate (109-94-4). The studies are as mentioned below:

 

In a Chronic repeated dose oral toxicity study, Osborne-Mendel male and female rats treated with test substance in the concentrations of50, 125 and 500mg/kg bw orally in diet. The animals were observed for clinical sign, body weight, food consumption, Hematology, gross and Histopathology. Results show that no effect was observed on survival and growth of all the treated rats. Similarly, no effect was observed on hematological parameters of treated rat as compared to control. In addition, No gross pathological abnormalities and microscopic changes in the tissues were observed in all treated rat as compared to control. Therefore, NOAEL was considered to be 500 mg/kg body weight/day when Osborne-Mendel male and female rats treated with test substance for 17 weeks by oral feed.

 

Based on the data available from the test chemical, Ethyl formate does not exhibit repeated dose oral toxicity. Hence the test chemical is not likely to classify as a repeated dose oral toxicity as per the criteria mentioned in CLP regulation.

 

Repeated dose inhalation toxicity:

Data available for the test chemicals was reviewed to determine the repeated dose oral toxicity of the test chemical and read across. The studies are as mentioned below:

 

In a Repeated dose inhalation toxicity study, Sprague-Dawley male and female rats were inhaled with test substance in the concentration of 0, 0.2, 1 and 4 mg/L for 6 hr/day, 5 days by Whole body exposure for 90 days. Decrease in locomotor activity of the male and female rats were observed as compared to control, but recovered after the exposure ended at 4 mg/L. No mortality was observed during the study in treated rats as compared to control. Body weight gain significantly decreased in male and female rats from week 1 were observed as compared to control rats. Increased body weight gain on week 4 were observed in male rat as compared to control at 4 mg/L and increased body weight gain on week 4 in male rats were observed as compared to control at 1 mg/L. The increased body weight of the male rats exposed to 330 ppm at week 4 was not considered to be ethyl formate-related change because they were isolated changes. Significantly decreased in male and female rat were observed from week 1 and week 3, respectively as compared to control at 4 mg/L. Similarly, increased HGB and HCT level in male and decreased in Reti level n female rat were observed as compared to control and Ca and TG levels decreased in male and female rats respectively at 4 mg/L. Increase in Ketone body in male and female rat and Urobilinogen level in female rat were observed as compared to control. Increase in Ketone body in female rat were observed as compared to control at 1 mg/L. Reduced body weight and food consumption are occasionally accompanied by increase in urinary ketone levels, because energy metabolism under those conditions shifts from gluconeogenesis to incomplete oxidation of fatty acids. In addition, absolute and relative adrenal weight increased in male and female rats and relative brain, kidney, and lung in male and female rat as compared to control and Absolute or relative thymus weight or both decreased in male and female rats and absolute heart, kidney, liver, lung, and spleen weights decreased as compared to control at 4 mg/L. Degeneration, Squamous metaplasia and Lesions were mainly noted in the dorsal meatus and occasionally in the septum and turbinate in male and female rats as compared to control at 4 mg/L. Therefore, NOAEC was considered to 1 mg/L when Sprague-Dawley male and female rats were inhaled with ethyl formate for 90 days.

 

Mainstream smoke from blended research cigarettes with (test) and without (control) the addition of ingredients to the tobacco was assayed for inhalation toxicity. Male and female Sprague Dawley rats were nose-only exposed either to fresh air (sham) or to diluted mainstream smoke from the test, the control, or the Reference Cigarette 1R4F at a concentration of 150 pg total particulate matter/I for 90-days, 6 h/day, 7 days/week. A 42-day post-inhalation period was included to evaluate reversibility of possible findings. There were no remarkable differences in in-life observations or gross pathology between test and control groups. An increase in activity of liver enzymes, known to be due to the high smoke dose, revealed no toxicologically relevant differences between the test and control groups. No toxicological differences were seen between the test and control groups for smoke-related hematological changes, such as a decrease in total leukocyte count. Therefore, NOEC (NOEL) was considered to be 14 ppm when Sprague Dawley rats were exposed to test cigarette smoke by inhalation – nose only route.

 

Based on the data available from the test chemical, Ethyl formate does not exhibit repeated dose inhalation toxicity. Hence the test chemical is not likely to classify as a repeated dose oral toxicity as per the criteria mentioned in CLP regulation.

 

Repeated dose dermal toxicity:

Data available for the test chemicals was reviewed to determine the repeated dose oral toxicity of the test chemical. The studies are as mentioned below:

 

10 weeks repeated dermal study was conducted on male “s” strain mice with the dose concentration of 2760 mg/kg bw/day (0.3ml in acetone applied) and the histopathologic analysis is done to determine the toxic effects. No significant activity was observed In terms of epidermal hyperplasia. Therefore, NOAEL was considered to be 2760 mg/kg bw/day when male “s” strain mice were treated for 10 weeks.

 

Based on the data available from the test chemical, Ethyl formate (109-94-4) does not exhibit repeated dose dermal toxicity. Hence the test chemical is not likely to classify as a repeated dose dermal toxicity as per the criteria mentioned in CLP regulation.

Justification for classification or non-classification

Based on the data available for the test chemical Ethyl formate (109-94-4) does not exhibit toxic nature upon repeated exposure by oral, inhalation and dermal route of exposure and hence is not likely to classify as per the criteria mentioned in CLP regulation.