Isopropyl 2-methylbutyrate

Endpoint summary

Description of key information

Studies for these endpoints returned results of not irritating to skin and not irritating to eyes.

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:

key study

Study period:

14 to 28 June 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

not specified

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Elevage Scientifique des Dombes
- Age at study initiation: : Age at start of treatment: 13 weeks (not specified but considered to be weeks)
- Weight at study initiation:
- Housing: Individually in stainless steel cages equipped with feed hoppers, drinking water bowls, with wood and haysticks for gnawing.
- Diet: Pelleted standard Provimi Kliba 3418 rabbit maintenance diet ad libitum.
- Water: Community tap water ad libitum, in water bowls.
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 40 - 70% (relative humidity)
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 / 12

:

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mI/animal (left side only)

Duration of treatment / exposure:

4 hours

Observation period:

Viability/mortality: Daily
Clinical signs: Daily during the observation period
Body weights: At start of acclimatization, on the day of application and at termination of observation
Room environment: Monitored continuously with hourly recordings

Number of animals:

1 male, 2 females

Details on study design:

TEST SITE
- Area of exposure: approximately 6 cm2
- % coverage: no data
- Type of wrap if used: The semi-occlusive dressing was wrapped around the abdomen and anchored with tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was removed and the skin was flushed with lukewarm tap water to clean the application site so that any reactions (erythema) were clearly visible at that time.
- Time after start of exposure: The duration of treatment was 4 hours

SCORING SYSTEM: The primary irritation score was calculated by totalling the individual cumulative scores at 24, 48 and 72 hours and then divided by the number of data points.

Irritation parameter:

erythema score

Basis:

animal: both female rabbits

Time point:

24/48/72 h

Score:

0

Max. score:

0

Irritation parameter:

erythema score

Basis:

animal: male

Time point:

24/48/72 h

Score:

2

Max. score:

2

Irritation parameter:

erythema score

Basis:

animal: male

Time point:

7 d

Score:

1

Max. score:

1

Irritation parameter:

erythema score

Basis:

animal: male

Time point:

14 d

Score:

0

Max. score:

0

Irritation parameter:

edema score

Basis:

animal: both female rabbits

Time point:

24/48/72 h

Score:

0

Max. score:

0

Irritation parameter:

edema score

Basis:

animal: Male

Time point:

24/48/72 h

Score:

2

Max. score:

2

Irritation parameter:

edema score

Basis:

animal: male

Time point:

14 d

Score:

0

Max. score:

0

Interpretation of results:

GHS criteria not met

Conclusions:

Based upon the referred classification criteria, Isopropyl methyl-2-butyrate is considered to be “not irritating” to rabbit skin.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

03 to 05 September 1986.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target and source chemicals are of similar structure in the same family.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

3. ANALOGUE APPROACH JUSTIFICATION
The target substance has a base set of studies undertaken to confirm likeness in results with the source substance. Please see attached justification.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sample from sponsor with Batch no. DL 4979/F4-24
- Expiration date of the lot/batch: no data
- Purity test date: no data

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: none

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: obtained from ENKI-Konijnenfarm, Someren, the Netherlands
- Age at study initiation: young adult
- Weight at study initiation: body weight range 2500-3500 g
- Housing: The animals were identified by earmarking, and housed individually in suspended, galvanized cages, fitted with wire-mesh floor and front.
- Diet: A standard laboratory rabbit diet was provided ad libitum.
- Water: tap water was provided ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 ± 3°C
- Humidity (%): at least 40% (relative humidity)
- Air changes (per hr): ventilation c. 10 air changes/hour
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark cycle

Vehicle:

unchanged (no vehicle)

Controls:

other: The untreated eye

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.1 ml

Duration of treatment / exposure:

72 hours

Observation period (in vivo):

1, 24, 48 and 72 hours

Number of animals or in vitro replicates:

3

Details on study design:

Experimental design:
- Both eyes of each rabbit provisionally selected were examined within 24 hours before testing. Three animals without observable eye effects were used.
- One tenth of a millilitre of the undiluted test substance was allowed to fall on the everted lower lid of one eye of each rabbit. After administration the upper and lower eye lid were carefully closed and subsequently held together for about one second before releasing, to prevent loss of material. The other eye remaining untreated, served as a control. The eyes were not washed out following administration and the animals were released immediately.
- Ocular reactions were judged using the scoring scale which is given in an appendix at the end of this report.
- Eye effects were examined after one hour, 24, 48 and 72 hours, or until the eye effects had cleared completely.

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 1h

Score:

0

Max. score:

0

Reversibility:

not specified

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24 h

Score:

0

Max. score:

0

Reversibility:

not specified

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

48 h

Score:

0

Max. score:

0

Reversibility:

not specified

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 1h

Score:

0

Max. score:

0

Reversibility:

not specified

Irritation parameter:

iris score

Basis:

mean

Time point:

24 h

Score:

0

Max. score:

0

Reversibility:

not specified

Irritation parameter:

iris score

Basis:

mean

Time point:

48 h

Score:

0

Max. score:

0

Reversibility:

not specified

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 1h

Score:

1

Reversibility:

not specified

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24 h

Score:

1

Reversibility:

not specified

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

48 h

Score:

0

Max. score:

0

Reversibility:

not specified

- After one hour and after 24 hours, the eye effects observed in all (three) rabbits consisted of slight redness and slight swelling of the conjunctivae.

- After 48 hours, all eye effect had cleared completely.

Table 1. Individual Scores Awarded to the Ocular Lesions Elicited by Manzanate

Rabbit number	Cornea opacity	Iris	Conjunctivae
			Redness	Chemosis
			After one hour
4020	0	0	1	1
4022	0	0	1	1
4023	0	0	1	1
			After 24 hours
4020	0	0	1	1
4022	0	0	1	1
4023	0	0	1	1
			After 48 hours
4020	0	0	0	0
4022	0	0	0	0
4023	0	0	0	0

Interpretation of results:

GHS criteria not met

Conclusions:

According to EU guidelines the test substance Manzanate is not irritating to eyes.

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 to 16 May 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The source and target chemicals are similar and a base set of studies has confirmed similar results.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Purity is similar with insignificant impurities.

3. ANALOGUE APPROACH JUSTIFICATION
Please see attched justification.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No.of test material: 20010036
- Expiration date of the lot/batch: no data
- Purity test date:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: cool and dry
- Stability under test conditions: 360 days

Species:

rabbit

Strain:

other: SPF Albino rabbits of stock Chbb:HM (SPF) – Little russian

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: BI Pharma KG, 88397 Biberach
- Age at study initiation: No details provided in report
- Weight at study initiation: 1.9 - 2.1 kg bw
- Housing: During a pre-period of at least one week and throughout the experiment the rabbits were caged individually in PPO cages (floor area: 2576 sq.cm) with perforated floor.
- Diet (e.g. ad libitum): A pelleted complete rabbit diet “Altroimin 2123” from Altromin, D-32791 Lage, Lippe, was available ad libitum. Analyses for major nutritive components and relevant possible contaminants are performed regularly on the diet. Certificates of analysis are retained.
- Water (e.g. ad libitum): The animals had free access to bottles with domestic quality drinking water acidified with hydrochloric acid to pH 2.5 in order to prevent microbial growth. Analyses for relevant possible contaminants are performed regularly. Certificates of analysis are retained.

ENVIRONMENTAL CONDITIONS
The study took place in animal room No. 6 provided with filtered air at the following conditions:
- Temperature (°C): 20 ± 3
- Humidity (%): 55 ± 15
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 hours light and 12 hours darkness. Light was on from 6 am to 6 pm

Vehicle:

unchanged (no vehicle)

Controls:

other: The untreated right eye

Amount / concentration applied:

0.1 ml

Duration of treatment / exposure:

24 hours

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

4 female (The study was initiated with one rabbit. Since no marked eye irritation was seen in this animal another three rabbits were included in the study with time difference).

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The eyes were examined and the grade of ocular reaction was recorded one hour and 24 hours later. After the first 24 hour reading Fluorescein was instilled. After rinsing with 20 ml 0.9% sodium chloride solution the eyes were examined again using UV-light to detect possible corneal damage.
- Time after start of exposure: 24 hours

SCORING SYSTEM: Alll scoring was on a 0 to 4 scale with 0 being no or little effect to 4 being extreme effect.

TOOL USED TO ASSESS SCORE: The day before testing both eyes of the animals were examined with a hand held inspection lamp fitted with white and UV light and magnifying glass with, 2 x magnification to ensure there were no defects or irritation. The examination was performed before and after instillation of Fluorescein.

The eyes were examined and the grade of ocular reaction was recorded one hour and 24 hours later. After the first 24 hour reading Fluorescein was instilled. After rinsing with 20 ml 0.9% sodium chloride solution the eyes were examined again using UV-light to detect possible corneal damage.

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0.67

Max. score:

2

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

- One hour after application of the test article animals No. 1770 and No. 1773 showed a diffuse, crimson red conjunctiva with individual vessels not easily discernible, an obvious swelling with partial eversion of lids and a discharge with moistening of the lids and hairs just adjacent to lids in animals No. 1771 and No. 1772 were observed a diffuse, crimson red conjunctiva with individual vessels not easily discernible, an obvious swelling with partial eversion of lids and a discharge different from normal.

 

- 24 hours after application of the test article animals No. 1770 and No. 1772 showed some conjunctival vessels definitely injected and a swelling above normal. In animal No. 1771 were observed a diffuse, crimson red conjunctiva with individual vessels not easily discernible as well as an obvious swelling with partial eversion of lids. Animal No. 1773 showed a diffuse, crimson red conjunctiva with individual vessels not easily discernible as well as a swelling above normal.

 

- 48 hours after application of the test article in animals No. 1770 and No. 1771 were observed some conjunctival vessels definitely injected and a swelling above normal. Animals No 1772 and No. 1773 showed some conjunctival vessels definitely injected.

 

- 72 hours after application of the test article in animals No. 1770 and No. 1773 were observed some conjunctival vessels definitely. Animal No. 1771 showed some conjunctival vessels definitely injected and a swelling above normal. In animal No. 1772 was observed a conjunctival swelling above normal.

 

- 7 days after application of the test article all four animals were free of any signs of eye irritation.

 

The following mean values were obtained;:

 

cornea opacity         0.0

iris lesion                  0.0

redness of conjunctiva   1.1

oedema of conjunctiva (chemosis) 0.8

Interpretation of results:

GHS criteria not met

Conclusions:

According to EU guidelines this substance is not classfied as irritating.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

IMB is not classified for skin irritation as no adverse effects were seen in a high quality study. IMB is not classified for eye irritation as both read-across substances, EMB and EMV, returned negative results.