Cyclopentanone

Endpoint summary

Description of key information

Cyclopentanone is officially classified as irritating to eyes and skin in CLP Annex VI tables 3.1 and 3.2 of the regulation 1272/2008.

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The used protocol was the method published by the OECD. However, the purity of the test substance was not noted and the GLP were not mentioned.

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

occlusive application, surface area 4 cm²

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

- Source: Roucher SA, Couhé
- Weight at study initiation: about 2.5 kg
- Age at study initiation, housing, diet, water, acclimation period: data not available

ENVIRONMENTAL CONDITIONS (temperature, humidity, air changes, photoperiod) data not available

IN-LIFE DATES: data not available

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

undiluted

Duration of treatment / exposure:

4 hour(s)

Observation period:

72 hours (up to 7 or 14 days if pronounced irritation)

Number of animals:

6

Details on study design:

TEST SITE:
- Area of exposure: 2 x 2 cm
- % coverage: data not available
- Type of wrap if used: gauze + patch

REMOVAL OF TEST SUBSTANCE: data not available

SCORING SYSTEM: according to Draize (1948)
PDII below 0.5, non-irritant; 0.5-3, slightly irritant; 3-5, moderately irritant; 5-8, severely irritant (AFNOR scale)

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Score:

3

Max. score:

8

Reversibility:

no data

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

not measured/tested

In the same conditions but with a semi-occlusive protocol, the  PDII was 0.31.
No other information are available

Interpretation of results:

other: Slightly irritating. Classified as irritant in the annex VI 3.2 of the CLP regulation 1272/2008

Conclusions:

Slightly irritating.
Classified as irritant in the annex VI 3.2 of the CLP regulation 1272/2008

Executive summary:

In a primary dermal irritation study (Guillot JP, 1982), New Zealand White rabbits (6/group) were dermally exposed to 0.5 mL of cyclopentanone (purity unknown) undiluted for 4 hours to the flanks.  Test sites were covered with an occlusive dressing for 4 hours. Animals then were observed for 3 days. Irritation was scored by the method of Draize.

In this study, Cyclopentanone was slightly irritating to the skin in rabbit.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The used protocol was the method published by the OECD. However, the purity of the test substance was not noted and the GLP were not mentioned. The number of scores were not detailed.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

not specified

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS:
- Source: Roucher SA, Couhé
- Weight at study initiation: about 2.5 kg
- Age at study initiation, housing, diet, water, acclimation period data not available

ENVIRONMENTAL CONDITIONS (temperature, humidity, air changes, photoperiod): data not available

IN-LIFE DATES: data not available

Vehicle:

unchanged (no vehicle)

Controls:

other: the other eye served as control

Amount / concentration applied:

undiluted
Amount applied: 0.1 ml

Duration of treatment / exposure:

not rinsed or rinsed after 4 and 30 s

Observation period (in vivo):

observation at 1 h, 1, 2, 3, 4 and 7 days after instillation and, in case where lesion persisted, also at later stages

Number of animals or in vitro replicates:

6

Details on study design:

- Removal of test system: washing with Dacryoserum after 4 or 30 s (or not rinsed)

- Scoring system: at each observation time, lesions of the conjonctiva, iris and cornea were recorded separately using a numerical system based on that of Kay & Calandra (1962), the sum of these scores being the individual ocular irritation index (IOI) of each animal. Calculation of the mean of the IOI values (over six rabbits) gave the mean ocular irritation index (MOI). The greatest MOI obtained over the range of observation times was identified as the acute ocular irritation index (AOI; corresponding to the OECD approach) which was used for the classification of the substance in one of six categories between "non-irritant" and "extremely irritant" (AFNOR scale). The maximum value of index is 110.

- Tool used to assess score: data not available

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: AOI

Score:

54.33

Max. score:

110

Reversibility:

not specified

Remarks on result:

other: see results below

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

not measured/tested

- Irritation score: 
Rinsing        AOI (*)                MOI                IOI
procedure
None                54.33                43.67 [d7]         > 30 (d4)
30 sec              49.67                17.50 [d7]         > 30 (d1)
4 sec                54.66                20.67 [d7]
*: the AOI was the 24-hr MOI

- Remarks: Cyclopentanone is considered as "severely irritant" according to the AFNOR quotation since: 
        -  IOI at day 7 was > 30 without rinsing (for 4 rabbits / 6 rabbits) and with rinsing at 30 seconds (1 rabbit / 3 rabbits).
        - MOI after 7 days was 43.67 without rinsing, 17.50 after rinsing at 30 seconds and 20.67 after rinsing at 4 seconds.
        - AOI = 54.33 of the OECD approach without rinsing procedure. After rinsing at 30 or 4 seconds, AOI (at 24 hours) was 49.67 or 54.66 respectively. 

Rinsing reduced the severity of the eye lesions and even affected a significant reversibility by day 14 or 21, although rinsing at 4 or 30 seconds did not change the classification.

Interpretation of results:

other: Irritating to the eye. Classified as irritant in the annex VI 3.2 of the CLP regulation 1272/2008

Conclusions:

Irritating to the eye.
Classified as irritant in the annex VI 3.2 of the CLP regulation 1272/2008

Executive summary:

In a primary eye irritation study [Guillot, 1982], 0.1 mL of undiluted cyclopentanone (purity unknown) was instilled into the conjunctival sac of the eye of New Zealand White rabbits (6/group). The eyes were not rinsed, or rinsed after 4 or 30 sec. Animals then were observed for at least 7 days.  Irritation was scored by the method of Kay & Calandra, and using the AFNOR scale.

In this study, cyclopentanone was irritating to the eye.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin:

Three studies with reliability 2 and one with reliability 3 were available. One of them with reliability 2 (Guillot JP, 1982), was selected as key study because it followed the recognized guideline:

In a primary dermal irritation study New Zealand White rabbits (6/group) were dermally exposed to 0.5 mL of cyclopentanone (purity unknown) undiluted for 4 hours to the flanks. Test sites were covered with an occlusive dressing for 4 hours. Animals then were observed for 3 days. Irritation was scored by the method of Draize. The mean Primary Dermal Irritation Index (PDII) was 3 (Maximum score: 8).

In this study, Cyclopentanone is slightly irritating to the skin in rabbits.

Eye:

Two studies with reliability 2 according to Klimisch were available. One of them was selected as key study.

In a primary eye irritation study [Guillot, 1982], 0.1 mL of undiluted cyclopentanone (purity unknown) was instilled into the conjunctival sac of the eye of New Zealand White rabbits (6/group). The eyes were not rinsed, or rinsed after 4 or 30 sec. Animals then were observed for at least 7 days. Irritation was scored by the method of Kay & Calandra, and using the AFNOR scale. Score was 54.33/110 (AOI: Acute Ocular Irritation).

Therefore, based on this study, cyclopentanone is considered as irritating to the eyes in rabbits.

Justification for classification or non-classification

The official classification of cyclopentanone is the following:

- Eye irrit. Category 2 (H319: Causes serious eye irritation) and Skin irrit. Category 2 (H315: Causes skin irritation) according to CLP Annex VI table3.1 of the Regulation 1272/2008.

Results of key studies are in accordance with the official classification.