Pentyl formate

Endpoint summary

Description of key information

Skin irritation:

The dermal irritation potential of target chemical was assessedin various in- vitro and in-vivo experimental studies.Based on the available studies,it can be concluded that the testchemical is able to cause skin irritation and considered as irritating. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Category 2 (irritant) ''. 

Eye irritation:

The ocular irritation potential of Pentyl Formate (CAS No: 638-49-3) was estimated using OECD QSAR toolbox version 3.3 with logPow as the primary descriptor. The substance Pentyl Formate (CAS No: 638-49-3) is estimated to be irritating to the eyes of rabbits.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

equivalent or similar to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

The skin irritation test was conducted in rabbits for test chemical Pentyl Formate (CAS No:638-49-3) to assess its skin irritancy potential.

GLP compliance:

not specified

Specific details on test material used for the study:

Name of test material (as cited in study report):pentyl formate
- Molecular formula :C6H12O2
- Molecular weight :116.158g/mole
- Substance type:organic
- Physical state:No data available
Purity:No data available
- Impurities (identity and concentrations):No data available

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

No data available

Type of coverage:

occlusive

Preparation of test site:

other: Intact or abraded skin

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

100%

Duration of treatment / exposure:

24hr

Observation period:

24hr

Number of animals:

No data available

Details on study design:

No data available

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24 h

Reversibility:

not specified

Remarks on result:

positive indication of irritation

Irritant / corrosive response data:

Slightly skin irritation was observed in treated rabbits.

Other effects:

No data available

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

The test material Pentyl Formate (CAS No:638-49-3) was considered to be slightly irritating to the skin of rabbits under occlusive condition

Executive summary:

The skin irritation study was conducted in rabbits for test chemical Pentyl Formate (CAS No: 638-49-3) to assess its skin irritancy potential.

 

 The undiluted Pentyl Formate was applied to the intact or abraded skin of each rabbit which produce slight irritation under occlusive condition.

 

Hence Pentyl Formate (CAS No: 638-49-3) was considered to be slightly irritating to the skin of rabbits.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from experimental study report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

Principles of method if other than guideline:

The purpose of this study was to assess potential for the test article to be ocular irritants. The ocular irritation potential of a test article may be predicted by measurement of its cytotoxic effect, as reflected in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, in the MatTek EpiOcular™ model

GLP compliance:

no

Species:

human

Strain:

other: Not applicable

Details on test animals or tissues and environmental conditions:

- Description of the cell system used:
The normal human-derived keratinocytes were cultured at the air-liquid interface in a chemically defined medium on a permeable polycarbonate insert (surface 0.5 cm2). They were cultured in chemically defined serum free medium to form a multi-layered epithelium similar to that found in native corneal mucosa. Each lot of tissues was Quality Assured by MatTek according to specific QC standards including: histology, tissue viability (MTT mean optical density), reproducibility (SD) and tissue thickness.

- Test System Identification
All of the EpiOcular™ 3-dimensional human tissues used in this study were identified by the date of arrival and the lot number. Certificate of Analysis for the tissues is included in this report. Tissue plates were appropriately labeled with study information. Bias was not a factor in this test system.

- Justification of the test method and considerations regarding applicability
EpiOcularTM Eye Irritation (OCL) by MatTek In Vitro Life Science Laboratories, Bratislava, Slovakien.
The test articles and controls were evaluated for potential ocular irritancy using the EpiOcular™ 3 dimensional human tissue model purchased from MatTek In Vitro Life Science Laboratories, Bratislava, Slovakien.
The EpiOcular tissue construct is a nonkeratinized epithelium prepared from normal human keratinocytes (MatTek). It models the cornea epithelium with progressively stratified, but not cornified cells. These cells are not transformed or transfected with genes to induce an extended life span in culture. The “tissue” is prepared in inserts with a porous membrane through which the nutrients pass to the cells. A cell suspension is seeded into the insert in specialized medium. After an initial period of submerged culture, the medium is removed from the top of the tissue so that the epithelial surface is in direct contact with the air. This allows the test material to be directly applied to the epithelial surface in a fashion similar to how the corneal epithelium would be exposed in vivo. Each lot of tissues was Quality Assured by MatTek In Vitro Life Science Laboratories according to specific QC standards including: histology (cell layers), tissue viability (MTT mean optical density) and reproducibility (SD)

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 μL of liquid test article
- Concentration (if solution): neat (undiluted)

VEHICLE (no vehicle)
- Amount(s) applied (volume or weight with unit): none
- Concentration (if solution): none
- Lot/batch no. (if required): none
- Purity: none

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): neat

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): neat

Duration of treatment / exposure:

Tissues were exposed for approximately 30 minutes for liquid test article and controls, at approximately 37°C, 5% CO2 in a humidified incubator.

Observation period (in vivo):

Not applicable

Duration of post- treatment incubation (in vitro):

Following the washing step and the post-soak, the tissues were incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of ~2 hours for liquid test articles , or 18 hrs for solid test articles, and controls.

Number of animals or in vitro replicates:

2 tissues were used for test compound and control.

Details on study design:

- Details of the test procedure used
The tissues were exposed to the test article neat (undiluted). EpiOcular™ tissues were purchased from MatTek. Quality control of the tissues was performed by MatTek and the Certificate of Analysis (CoA) for the tissues is provided and is kept in the study binder. Tissues were exposed for approximately 30 minutes for liquid test articles and controls, at approximately 37°C, 5% CO2 in a humidified incubator. After the exposure, the test article was rinsed off the tissues and the tissues were soaked in media for ~12 minutes for liquid test articles and controls. Following the washing step and the post-soak, the tissues were incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of ~2 hours for liquid test articles and controls. Tissue viability was assessed by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

- MTT Auto reduction and colouring assessment
MTT Pre-test
The test article was assessed for the potential to interfere with the assay. Approximately 50 µL of liquid test article was added to 1 mL of MTT media (~1 mg/mL) and incubated in a humidified incubator at approximately 37°C and approximately 5% CO2 for 3 hours. 50 µL of ultrapure water was used as a negative control.

- Test Article Color Test
Approximately 50 µL of liquid test article was added to 1.0 mL of ultrapure water and 2.0 mL isopropanol and incubated in a humidified incubator at approximately 37°C and approximately 5% CO2 for 2 hours, 04 minutes and 35 seconds. Samples were then added to the wells of a clear 96-well plate and the plate was read on a Thermo Scientific Multiskan FC Microplate Photometer to 570 nm. Test articles that tested positive for excessive coloration (OD >0.08) were assessed on living-tissue controls that were incubated in both culture media and MTT media as well (n=3 for both conditions).

- MTT Assay:
After the recovery period, the MTT assay was performed on run 1 tissues by transferring the tissues to 24-well plates containing 300 µL MTT medium (1.0 mg/mL). After 3 hours of MTT incubation at approximately 37°C, approximately 5% CO2 in a humidified incubator.The blue formazan salt was extracted by submerging tissues in 2 mL isopropanol in a 24-well plate. The extraction for liquid exposed tissues was overnight incubation. The optical density of the extracted formazan (200 µL/well of a 96-well plate) was determined using a Thermo Scientific Multiskan FC Microplate Photometer at 570 nm. Relative cell viability was calculated for each tissue as % of the mean negative control tissues

- Evaluation of Test Article in the cell Models
1. Cell System:
Upon receipt, the MatTek EpiOcular™ tissue cultures were placed in 1.0 mL of fresh Maintenance medium (in a 6-well plate) for 60 minutes. After the 60 minutes incubation, the Maintenance medium was exchanged with fresh medium and the tissues were incubated overnight (16-24 hrs) at approximately 37°C, approximately 5% CO2 in a humidified incubator.
2. Control and Test Article Exposures:
20 µL of calcium and magnesium free DPBS was added to each tissue and the tissues placed back into the incubator for 30 minutes. The controls and the test article will be applied topically to tissues by pipette. Three tissues will be used per test compound and control.
a)Controls: 50 µL of negative control sterile ultrapure water and positive control methyl acetate were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
b)Test Article: 50 µL of liquid test article were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
3. Post exposure treatment:
After the exposure, the tissues were rinsed 20 times with sterile DPBS to remove test material. The apical surface was gently blotted with a cotton swab and cultures were immediately transferred to a 12-well plate containing 5 mL of media per well. Tissues exposed to liquid test articles (and the respective control) were incubated, submerged in the media for ~12 minutes at room temperature.For liquid test articles, tissues, Tissuses were then transferred to 6-well plates containing 1.0 mL fresh Maintenance medium per well and incubated for a post-exposure recovery period for 2 hours at approximately 37 degC, 5% CO2 in a humidified incubator.
- Doses of test chemical and control substances used
Test Article:
50 µL of liquid test article were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
Controls: 50 µL of negative control sterile ultrapure water, positive control methyl acetate were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
- Duration and temperature of exposure, post-exposure immersion and post-exposure incubation periods: Tissues were exposed for approximately 30 minutes for liquid test articles and controls, at approximately 37°C, 5% CO2 in a humidified incubator. Following the washing step and the, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time totaling ~2 hours for liquid test articles and controls.
- Justification for the use of a different negative control than ultrapure H2O (Not applicable
- Justification for the use of a different positive control than neat methyl acetate (Not applicable)
- Number of tissue replicates used per test chemical and controls: 2 tissues were used for test compound and control.
- Description of the method used to quantify MTT formazan
The blue formazan salt was extracted by submerging tissues in 2 mL isopropanol in a 24-well plate. The extraction for liquid exposed tissues was overnight incubation with a 20 minute 24 second shake the following morning. The optical density of the extracted formazan (200 µL/well of a 96-well plate) was determined using a Thermo Scientific Multiskan FC Microplate Photometer at 570 nm. The blue formazan salt was extracted by placing the tissue insterts in 1 mL isopropanol in a 6-well plate. The extraction for solid exposed tissues was 3 hrs incubation. After an addition of 1 ml isopropanol and mixing, the optical density of the extracted formazan (200μL/well of a 96-well plate) was determined using a Thermo Scientific Multiskan FC Microplate Photometer at 570 nm.

- Description of evaluation criteria used including the justification for the selection of the cut-off point for the prediction model
Calculations and Statistical Methods
MTT Assay
Blanks:
· The OD mean from all replicates for each plate (ODblank).
Negative Controls (NC):
· The blank corrected value was calculated: ODNC= ODNCraw– ODblank.
· The OD mean per NC tissue was calculated.
· The mean OD for all tissues corresponds to 100% viability.
· The mean, standard deviation (SD), standard error of the mean (SEM) and the percent coefficient of variation (% CV) was calculated.
ODblank= optical density of blank samples (isopropanol alone).
ODNCraw= optical density negative control samples.
ODNC= optical density of negative control samples after background subtraction.
Positive Control (PC):
· Calculate the blank corrected value: ODPC= ODPCraw– ODblank.
· The OD mean per PC tissue was calculated.
· The viability per tissue was calculated: %PC = [ODPC/ mean ODNC] x 100.
· The mean viability for all tissues was calculated: Mean PC = Σ %PC / number of tissues.
· The standard deviation (SD), standard error of the mean (SEM) and the percent coefficient of variation (% CV) was calculated.
ODPCraw= optical density positive control samples.
ODPC= optical density of positive control samples after background subtraction.
Tested Articles:
· Calculate the blank corrected value ODTT= ODTTraw– ODblank.
· The OD mean per tissue is calculated.
· The viability per tissue is calculated: %TT = [ODTT/ mean ODNC] x 100.
· The mean viability for all tissues is calculated: Mean TT = Σ %TT / number of tissues.
· The standard deviation (SD) and the percent coefficient of variation (% CV)for the controls and the test articles will be calculated.
ODTTraw= optical density test article samples.
ODPC= optical density of test article samples after background subtraction.
Data Correction Procedure for MTT Interfering Compounds
True viability = Viability of treated tissue – Interference from test article = ODtvt – ODkt where ODkt = (mean ODtkt – mean ODukt).
ODtvt = optical density of treated viable tissue
ODkt = optical density of killed tissues
ODtkt = optical density of treated killed tissue
ODukt = optical density of untreated killed tissue (NC treated tissue)

Data Correction Procedure for Colored Compounds
True viability = Viability of treated tissue incubated in MTT media – Viability of treated tissue incubated in media without MTT = ODtvt – ODvt.
ODtvt = optical density of treated viable tissue incubated in MTT media
ODvt = optical density of viable tissues incubated in media alone.
Proposed Statistical methods
The mean, standard deviation (SD) and the percent coefficient of variation (% CV) for the controls and the test article will be calculated.
- Evaluation of data
The results of the assay was evaluated and compared to negative control.
Table: Irritancy Prediction
In VitroResults In VivoPrediction
Mean tissue viability ≤60% Irritant (I) – Category 1 or 2
Mean tissue viability >60% Non-irritant (NI) – No Category
- Assay quality controls
- Negative Controls (NC)
The assay is meeting the acceptance criterion if the mean viability of the NC in terms of Optical Density (OD570) of the NC tissues (treated with sterile ultrapure water) in the MTT assay are >0.8 to <2.5. This is an indicator of tissue viability following shipping and conditions under use.
- Positive Controls (PC)
Methyl acetate was used as a PC and tested concurrently with the test article. The assay is meeting the acceptance criteria if the viability of the PC is <50% of the negative control.
- Standard Deviation (SD)Each test of ocular irritancy potential is predicted from the mean viability determined on 3 single tissues. The assay meets the acceptance criteria if SD calculated from individual percent tissue viabilities of the replicates is <18% for three replicate tissues.

Irritation parameter:

other: mean % tissue viability

Run / experiment:

Run 1

Value:

2

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

positive irritation observed

Other effects / acceptance of results:

The MTT data show the assay quality controls were met.

Table:

	mean	Dif.	mean of	Dif.	Dif./2	Classification
	of OD	of OD	viabilities [%]	of viabilities
NC	2.937	0.196	100.0	6.68	3.34	NI	qualified
PC	0.926	0.017	31.5	0.59	0.30	I	qualified
638-49-3	0.060	0.007	2.0	0.25	0.12	I	qualified

 

Code N°	Tissue	Raw data		Blank corrected data		mean of OD	% of viability
	n	Aliq. 1	Aliq. 2	Aliq. 1	Aliq. 2
NC	1	3.1865	2.9581	3.150	2.921	3.035	103.3
	2	2.815	2.9373	2.778	2.900	2.839	96.7
PC	1	0.9553	0.9523	0.918	0.915	0.917	31.2
	2	0.9687	0.9737	0.932	0.937	0.934	31.8
638-49-3	1	0.1008	0.0997	0.064	0.063	0.063	2.2
	2	0.0922	0.0937	0.055	0.057	0.056	1.9

Interpretation of results:

other: irritating

Conclusions:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline followed for this study. The mean % tissue viability of test substance Pentyl formate (CAS No.638-49-3) was determined to be 2.0%. Thus, substance Pentyl formate (CAS No: 638-49-3) was considered to be irritating to the human eyes.

Executive summary:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline for this study. The MatTek EpiOcular™ model was used to assess the potential ocular irritation of the test articles by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to liquid test articles and controls for ~30 minutes, followed by a ~12 minute post-soak and approximately 2 hour recovery after the post-soak. The viability of each tissue was determined by MTT assay.

The MTT data show the assay quality controls were met, passing the acceptance criteria.

The mean % tissue viability of test substance Pentyl formate (CAS No: 638-49-3) was determined to be 2.0%. Hence, under the experimental test conditions it was concluded that test substance Pentyl formate (CAS No: 638-49-3) was considered to be irritating to the human eyes and can thus be classified as ‘’Irritating to eyes in Category 2” as per CLP Regulation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation:

In different studies, the test chemical has been investigated for potential for dermal irritation to a greater or lesser extent. The studies are based on in- vitro and in-vivo experimental conducted in human and rabbits which have been summarized as below:

The dermal irritation potential of test article was determined according to the OECD 439 test guideline for this study. The MatTek EpiDerm™ model was used to assess the potential dermal irritation of the test article by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to the test article and controls for ~one hour, followed by a 42 hour post-exposure recovery period. The viability of each tissue was determined by MTT assay. The MTT data show the assay quality controls were met and passed the acceptance of criteria. The mean of OD  for test chemical was determined to be 0.037.The standard deviation of viabilities for test chemical were calculated to be 0.006.The Mean % tissue viability compared to negative control (n=3) of the test chemical was determined to be 1.7%.Hence, under the current experimental test conditions it was concluded that test chemical was considered to be irritating to human skin.

D. L. J. Opdyke (1980) conducted skin irritation studies in rabbits and human subjects for test chemical Pentyl Formate (CAS No: 638-49-3) to assess its skin irritancy potential as follows;.

In rabbits, the undiluted Pentyl Formate was applied to the intact or abraded skin of each rabbit which produce slight irritation under occlusive condition. Hence Pentyl Formate (CAS No: 638-49-3) was considered to be slightly irritating to the skin of rabbits.

In next study, a closed patch test was performed on human subjects to determine the skin irritation potential of test chemical Pentyl Formate (CAS No: 638-49-3). The subjects were exposed to the chemical at a concentration of 3% in petrolatum under occlusive condition and observed for cutaneous reactions. None of the subject induced any skin reactions. Thus the Pentyl Formate (CAS No: 638-49-3) was considered to be not irritating to the human skin in a closed patch test.

Cosmetic Ingredient Review Expert Panel (1989) carried out the primary skin irritation study for structurally similar substance Butyl Acetate (CAS no: 123-86-4) on 5 albino rabbits.In this study, the 0.01ml of undilutedButyl Acetate was applied dermally on clipped skin of each rabbits and the skin reactions were scoredwithin 24 h of the application.The reactions reported were the most severe seen and scored as a Grade 1 irritant indicating “the least visible capillary injection” from the undiluted Butyl Acetate.Thus the chemical Butyl Acetate (CAS no: 123-86-4) was considered to be irritating to the skin of albino rabbits.

Cosmetic Ingredient Review Expert Panel (1989) reported the cumulative irritation potential of a nail polish containing the same read across substance Butyl Acetate (CAS no: 123-86-4) using 2 male and 11 female subjects which supports the above results.Each subject received25% of Butyl Acetate to the backs for 21 consecutive 23 h periods. The polish, 0.4 ml, was applied to a gauze patch 30 min before application in order to permit evaporation of its volatile ingredients. The patches were removed by the subjects and the reactions scored 1 h after their removal. The nail polish was given a composite total score of 138 of a 819 maximum value and a total calculated score for 10 panelists of 106.2 of a 630 maximum. Since the chemical induce slightly irritating effects,Butyl Acetate (CAS no: 123-86-4) was considered to be irritating to the skin of albino rabbits.

The above results were further supported by experimental study conducted by (IFA) GESTIS-database (2017)onstructurally similar read across substances n-Propyl acetate (CAS No: 109-60-4) in guinea pigs. Each animal received n-Propyl acetate dermally and observed for skin reactions. Since the guinea pigs produced slight skin irritating effects, n -Propyl acetate (CAS No: 109-60-4) was considered to be irritating to the skin of guinea pigs’

The last skin irritation study was reported by OECD SIDS (2008) for same read across substance n-Propyl acetate (CAS No: 109-60-4) on male New Zealand white rabbits to determine its adverse skin effects under occlusive condition. A volume of 20 ml/kg bw (17,756 mg/kg bw) n-propyl acetate was applied undiluted, to intact, nonabraded skin. Fur was clipped and removed from the entire trunk of each rabbit prior to application of the chemical. Four rabbits were included in each dose group. n-Propyl acetate was applied to the dorsal surface of the trunk and spread over as large an area as possible. The test material was retained on the skin beneath an impervious plastic film. Rabbits were immobilized during the 24-hr contact interval. After treatment, all wrappings were removed. Animals were observed for signs of toxicity after dosing, and throughout the 14-day observaton interval. The trated animals produced Erythema and necrosis of the skin was observed after 24-hr occluded exposure to n-propyl acetate. Therefore -Propyl acetate (CAS No: 109-60-4) was considered to be irritating to the rabbits skin.

All these studies lead to a conclusion that Test chemical is indeed not irritating to skin. Hence, comparing the above annotations with the criteria of CLP regulation, Test chemical can be classified under the category “category 2 -irritant”.

Eye irritation:

In different studies,the test chemicalPentyl Formate (CAS No: 638-49-3) has been investigated for potential for ocular irritationto observe the potential for dermal irritation to a greater or lesser extent. The studies are based on in vivo and in vitro experiments in rabbits for target chemical Pentyl Formate (CAS No: 638-49-3) and its structurally similar read across substancesn-Propyl acetate (CAS No: 109-60-4)andButyl Acetate (CAS no: 123-86-4).

The ocular irritation potential of test article was determined according to the OECD 492 test guideline for this study. The MatTek EpiOcular™ model was used to assess the potential ocular irritation of the test articles by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to liquid test articles and controls for ~30 minutes, followed by a ~12 minute post-soak and approximately 2 hour recovery after the post-soak. The viability of each tissue was determined by MTT assay.

The MTT data show the assay quality controls were met, passing the acceptance criteria.

The mean % tissue viability of test substance Pentyl formate (CAS No: 638-49-3) was determined to be 2.0%. Hence, under the experimental test conditions it was concluded that test substance Pentyl formate (CAS No: 638-49-3) was considered to be irritating to the human eyes and can thus be classified as ‘’Irritating to eyes in Category 2” as per CLP Regulation

Cosmetic Ingredient Review Expert Panel (1989) carried out ocular irritation study of a nail polish containing the structurally similar substance Butyl Acetate (CAS no: 123-86-4) using nine New Zealand White rabbits.Each rabbit received 0.1 ml of25% of Butyl Acetate into the conjunctiva of one eye whereas the other eye served as control. The reactions were scored 1, 2, 3, 4, and 7 days after the administration of the Butyl Acetate.In three of the rabbits the treated eye was rinsed with 20 ml of water 30 s after instillation of thechemical. The eyes of other six rabbits did not receive a water rinse.The reactions were scored 1, 2, 3, 4, and 7 days after the administration of the Butyl Acetate. In the eyes of the rabbits that did not receive a water rinse, minimal corneal opacity was observed in three, moderate corneal opacity in two, and corneal stippling in six of the six rabbits tested. Minimal abnormalities were seen in the iris of five of six rabbits with nonrinsed eyes; the abnormalities had cleared by day 7 in all but one rabbit. Moderate to severe erythema and minimal to severe edema, as well as necrosis, were observed in the conjunctivas of rabbits not receiving a water rinse; most of the conjunctival irritation had cleared by day 7. In the three rabbits that received a water rinse, three had minimal corneal opacity and stippling that cleared after seven days. No abnormalities of the iris were seen in the rabbits that received a water rinse. Minimal to moderate erythema and edema were observed in three and two of the rabbits with rinsed eyes, respectively; these conjunctival effects had cleared by day 7.Since the chemical inducemoderate to severe irritation in unrinsed rabbit eyes and a mild irritation in rinsed rabbit eyes, the chemicalButyl Acetate (CAS no: 123-86-4)was considered to be irritating to the rabbits’ eye.

The above result was supported by an eye irritation study reported by Heldreth B, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler D, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Andersen FA. (2012) and OECD SIDS (2008) on structurally similar substance n-Propyl acetate (CAS No: 109-60-4) in rabbits to determine its adverse ocular effects. A flooding volume of 0.5 ml undiluted n-Propyl acetate was instilled directly into the rabbit eye and the eyes were not rinsed. Eye injury was recorded in a 10-grade series (Grade 1 negligible injury), based upon the degree of corneal injury. Instillation of an excess amount of undiluted propyl acetate into the rabbit eye produced some diffuse corneal injury, which healed quickly. Propyl acetate was designated Grade 2 on a scale of 10 (slight irritation). These results indicate that n-propyl acetate causes minimal corneal injury. Hence  n-Propyl acetate (CAS No: 109-60-4) was considered to be slightly irritating to the rabbits’ eye.

(IFA) GESTIS-database (2017) performed an eye irritation test on same read across substance n-Propyl acetate (CAS No: 109-60-4) to assess its eye irritancy potential which further supports the above result. In this test, 1 drop of n-Propyl acetate was installed into the eye of each rabbit and observed for ocular lesions. Since the rabbits showed reddening and insignificant swelling of the eyes, -Propyl acetate (CAS No: 109-60-4) was considered to be irritating to the eyes of rabbits’

Based on the available data for the target substance Pentyl Formate (CAS No: 638-49-3) and its structurally similar read across substancesn-Propyl acetate (CAS No: 109-60-4)andButyl Acetate (CAS no: 123-86-4),it can be concluded that chemical Pentyl Formate (CAS No: 638-49-3) andis able to cause eye irritation and considered as irritating.Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Category 2

Justification for classification or non-classification

The skin and eye irritation potential of test chemicalPentyl Formate (CAS No: 638-49-3) and its structurally similar read across substances Butyl Acetate (CAS no: 123-86-4) andn-Propyl acetate (CAS No: 109-60-4) were observed in various studies. The results obtained from these studies indicates that the chemical Pentyl Formate (CAS No: 638-49-3)is likely to cause skin and eye irritation. Hence 2 Pentyl Formate (CAS No: 638-49-3) can be classified under the category “Category 2” for skin and eye as per CLP.