Registration Dossier

Skin Irritation:

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not irritating to skin.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”.

Eye Irritation:

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not irritating to eyes.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”.

Reference

Endpoint:

skin irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Weight of evidence based on structurally similar chemicals

Justification for type of information:

Weight of evidence based on structurally similar chemicals

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

other: Weight of evidence approach based on similar chemicals

Principles of method if other than guideline:

The weight of evidence report has been prepared based on the read across substances identified based on structural and functional similarity to assess the dermal irritation potential of tert-butyl 3-oxobutanoate

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: tert-butyl 3-oxobutanoate- Molecular formula: C8H14O3- Molecular weight: 158.196 g/mol- Smiles notation: O(C(C)(C)C)C(CC(C)=O)=O- InChl: 1S/C8H14O3/c1-6(9)5-7(10)11-8(2,3)4/h5H2,1-4H3- Substance type: Organic- Physical state: Liquid

Species:

rabbit

Strain:

not specified

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

1. no data available2. 0.5 ml3. 0.01 ml

Duration of treatment / exposure:

1. no data available2. 4 hours3. 24 hours

Observation period:

1. no data available2. 24,48 hours till 7 days3. 24 hours

Number of animals:

1. no data available2. 63. 5

Details on study design:

The study is based on weight of evidence approach from the read across values

Irritation parameter:

overall irritation score

Basis:

mean

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No signs of irritation observed

Interpretation of results:

other: not irritating

Conclusions:

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not sensitizing to skin.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”.

Executive summary:

In different studies,tert-butyl 3-oxobutanoatehas been investigated for potential for dermal irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits for target chemical as well as its structurally similar read across chemicals. The results are summarized as follows:

Skin irritation effects were estimated by four different models i.e, Battery, Leadscope, SciQSAR and CASE Ultra used within Danish QSAR database for tert-butyl 3-oxobutanoate . Based on estimation, no severe skin irritation effects were known when tert-butyl 3-oxobutanoate was exposed to rabbit skin. Hence, tert-butyl 3-oxobutanoate can be considered not irritating to skin.

This estimated result is supported by an experimental performed to determine the primary dermal irritation potential of the structurally similar chemical in rabbits. 0.5 ml undiluted test chemical was applied to the clipped dorsal skin of 6 New Zealand White rabbits under occlusive wrapping for 4 hours. After 4 hours of exposure, the occlusive dressing was removed and the excess test chemical was gently removed. The test sites were inspected for erythema and edema at 1 hour, 1, 2, 3, 7 and 14 days post removal of the dressing. The dermal reactions were scored by the methods of Draize.

5 of 6 rabbits had a very slight local erythema, which also developed in the sixth animal by 24 hr. Edema, slight in 5 rabbits and moderate in one, was also present. After 3 days, only half the animals had just detectable erythema, and one had mild edema. Apart from mild desquamation, no effects were seen at 7days. Since the effects were completely healed by 7 days, the test chemical can be considered to be not irritating to skin.

The above results are further supported by another acute dermal irritation study carried out to assess the irritation potential of the other structurally similar chemical. Primary skin irritation on rabbits was recorded in a 10-grade ordinal series and was based upon the severest reaction that develops on the clipped abdominal skin of each of five albino rabbits within 24 hours of the uncovered application of 0.01 ml of undiluted sample or of solutions in water, propylene glycol, or acetone. Grade 1 indicates no irritation and Grade 2 the least visible capillary injection from the undiluted chemical. Grade 6 indicates necrosis when undiluted and Grade 10 indicates necrosis from a 0.01% solution. Primary Dermal Irritation score for the test chemical was Grade 2.

Based on the grade, the test chemical was considered to be not irritating to skin.

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not sensitizing to skin.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”.

Endpoint conclusion:

no adverse effect observed (not irritating)

Reference

Endpoint:

eye irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Weight of evidence approach based on similar chemicals

Justification for type of information:

Weight of evidence approach based on similar chemicals

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

other: Weight of evidence approach based on similar chemicals

Principles of method if other than guideline:

The weight of evidence report has been prepared based on the read across substances identified based on structural and functional similarity to assess the ocular irritation potential of tert-butyl 3-oxobutanoate

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: tert-butyl 3-oxobutanoate- Molecular formula: C8H14O3- Molecular weight: 158.196 g/mol- Smiles notation: O(C(C)(C)C)C(CC(C)=O)=O- InChl: 1S/C8H14O3/c1-6(9)5-7(10)11-8(2,3)4/h5H2,1-4H3- Substance type: Organic- Physical state: Liquid

Species:

rabbit

Strain:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

1. 0.1 ml2. 0.5ml

Duration of treatment / exposure:

single exposure

Observation period (in vivo):

24 hours

Duration of post- treatment incubation (in vitro):

no data available

Number of animals or in vitro replicates:

1. no data available2. 6

Details on study design:

The study is based on weight of evidence approach from the read across values

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24 h

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No signs of irritation observed

Interpretation of results:

other: not irritating

Conclusions:

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not irritating to eyes.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”.

Executive summary:

Based on the available studies for the structurally similar read across chemicals, weight of evidence approach was applied to assess the ocular irritation potential of tert-butyl 3 -oxobutanoate.

Acute toxicity studies were carried out to estimate the toxicity of the structurally similar chemical. Eye injury in rabbits was recorded in a 10- grade ordinal series and was based upon the degree of corneal necrosis that results from instillation of various volumes and concentrations of chemical. Grade 1 indicates at most a very small area of necrosis resulting from 0.5 ml of undiluted chemical in the eye. Grade 5 indicates a so-called severe burn from 0.005 ml, and Grade 10 indicates a severe burn from 0.5 ml of a 1% solution in water or propylene glycol.

Primary Eye Irritation score after 24 hours for the test chemical was Grade 2. Based on the grade, the test chemical was considered to be not irritating to eyes.

This is supported by the results of a study was performed to determine the primary ocular irritation potential of the other structurally similar chemical in rabbits.

0.1 ml of the test chemical was instilled Into the Inferior Conjunctival Sac of One Eye of Each of Six New Zealand white Rabbits. The eyelids were held together for 1 second. The treated eyes were observed for conjunctival redness, chemosis and iridial inflammation, corneal injury at 1,4,24 hours and 2,3,7 days post instillation. Corneal integrity was checked before dosing by the instillation of 2% Fluorescein and irrigation with water 20 seconds later. Only animals without Fluorescein staining were used.

There was no evidence of corneal injury on macroscopic inspection or following the instillation of 2% fluorescein. At 1-hr post instillation there was just detectable excess conjunctival redness in 5 rabbits, of which 2 showed slight chemosis and 1 a moderate chemosis. Mild iritis was seen in 2 animals, persisting up to 4 hr. All eyes got completely healed by 24 hr post instillation.

The Primary irritation scores after 24 hours for conjunctival redness, chemosis, discharge and iris were 0.

Based on the scores and observations, the test chemical can be considered to be not irritating to eyes.

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not irritating to eyes.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”.

Endpoint conclusion:

no adverse effect observed (not irritating)

Endpoint conclusion:

no study available

Skin Irritation:

In different studies,tert-butyl 3-oxobutanoatehas been investigated for potential for dermal irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits for target chemical as well as its structurally similar read across chemicals. The results are summarized as follows:

Skin irritation effects were estimated by four different models i.e, Battery, Leadscope, SciQSAR and CASE Ultra used within Danish QSAR database for tert-butyl 3-oxobutanoate . Based on estimation, no severe skin irritation effects were known when tert-butyl 3-oxobutanoate was exposed to rabbit skin. Hence, tert-butyl 3-oxobutanoate can be considered not irritating to skin.

This estimated result is supported by an experimental performed to determine the primary dermal irritation potential of the structurally similar chemical in rabbits. 0.5 ml undiluted test chemical was applied to the clipped dorsal skin of 6 New Zealand White rabbits under occlusive wrapping for 4 hours. After 4 hours of exposure, the occlusive dressing was removed and the excess test chemical was gently removed. The test sites were inspected for erythema and edema at 1 hour, 1, 2, 3, 7 and 14 days post removal of the dressing. The dermal reactions were scored by the methods of Draize.

5 of 6 rabbits had a very slight local erythema, which also developed in the sixth animal by 24 hr. Edema, slight in 5 rabbits and moderate in one, was also present. After 3 days, only half the animals had just detectable erythema, and one had mild edema. Apart from mild desquamation, no effects were seen at 7days. Since the effects were completely healed by 7 days, the test chemical can be considered to be not irritating to skin.

The above results are further supported by another acute dermal irritation study carried out to assess the irritation potential of the other structurally similar chemical. Primary skin irritation on rabbits was recorded in a 10-grade ordinal series and was based upon the severest reaction that develops on the clipped abdominal skin of each of five albino rabbits within 24 hours of the uncovered application of 0.01 ml of undiluted sample or of solutions in water, propylene glycol, or acetone. Grade 1 indicates no irritation and Grade 2 the least visible capillary injection from the undiluted chemical. Grade 6 indicates necrosis when undiluted and Grade 10 indicates necrosis from a 0.01% solution. Primary Dermal Irritation score for the test chemical was Grade 2.

Based on the grade, the test chemical was considered to be not irritating to skin.

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not irritating to skin.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”

Eye Irritation:

Based on the available studies for the structurally similar read across chemicals, weight of evidence approach was applied to assess the ocular irritation potential of tert-butyl 3-oxobutanoate.

Acute toxicity studies were carried out to estimate the toxicity of the structurally similar chemical. Eye injury in rabbits was recorded in a 10- grade ordinal series and was based upon the degree of corneal necrosis that results from instillation of various volumes and concentrations of chemical. Grade 1 indicates at most a very small area of necrosis resulting from 0.5 ml of undiluted chemical in the eye. Grade 5 indicates a so-called severe burn from 0.005 ml, and Grade 10 indicates a severe burn from 0.5 ml of a 1% solution in water or propylene glycol.

Primary Eye Irritation score after 24 hours for the test chemical was Grade 2. Based on the grade, the test chemical was considered to be not irritating to eyes.

This is supported by the results of a study was performed to determine the primary ocular irritation potential of the other structurally similar chemical in rabbits.

0.1 ml of the test chemical was instilled Into the Inferior Conjunctival Sac of One Eye of Each of Six New Zealand white Rabbits. The eyelids were held together for 1 second. The treated eyes were observed for conjunctival redness, chemosis and iridial inflammation, corneal injury at1,4,24 hours and 2,3,7 days post instillation. Corneal integrity was checked before dosing by the instillation of 2% Fluorescein and irrigation with water 20 seconds later. Only animals without Fluorescein staining were used.

There was no evidence of corneal injury on macroscopic inspection or following the instillation of 2% fluorescein. At 1-hr post instillation there was just detectable excess conjunctival redness in 5 rabbits, of which 2 showed slight chemosis and 1 a moderate chemosis. Mild iritis was seen in 2 animals, persisting up to 4 hr. All eyes got completely healed by 24 hr post instillation.

The Primary irritation scores after 24 hours for conjunctival redness, chemosis, discharge and iris were 0.

Based on the scores and observations, the test chemical can be considered to be not irritating to eyes.

Based on the available data for the structurally similar read across substances and applying the weight of evidence approach, it can be concluded that the target chemical will also tend to behave in a similar that of the read across substances. Therefore, tert-butyl 3-oxobutanoate was estimated to be not irritating to eyes.Comparing the above annotations with the criteria of CLP regulation,tert-butyl 3-oxobutanoatecan be classified under the category “Not Classified”.

The results of the experimental studies from the target as well its structurally similar read across substances indicate a possibility that tert-butyl 3-oxobutanoate can be not irritating to skin and eyes.

Hence by applying the weight of evidence approach, tert-butyl 3-oxobutanoate can be considered to be not irritating to skin and eyes. It can be classified under the category “Not Classified” as per CLP regulation.