2-pentylcyclopentan-1-one

Endpoint summary

Description of key information

Acute toxicity: oral: LD50 > 5000 mg/kg bw (similar to OECD 401 in rats, K, rel.2);
Acute toxicity: dermal: LD50 > 2000 mg/kg bw (similar to OECD 402 in rabbits, K, rel.2);
Acute toxicity: inhalation: waiver. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 13 to 27, 1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Pre-guideline and pre-GLP study. Only basic data given but the study is comparable to OECD TG 401 with minor deviations that do not affect the reliability of the study.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

(no details test animals and environmental conditions)

Principles of method if other than guideline:

Not applicable

GLP compliance:

no

Remarks:

(pre-GLP)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Sherman-Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 200-300 g
- Fasting period before study: Animals were fasted for 24 h before test material administration.
- Diet: Food, ad libitum
- Water: Water, ad libitum

IN-LIFE DATES: From: November 13, 1978 To: November 27, 1978

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Animals were observed for mortality and clinical signs daily for 14 days. Initial and final bodyweights of animals were recorded.
- Necropsy of survivors performed: Yes; animals were subjected to gross necropsy.

Statistics:

None

Preliminary study:

Not applicable

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No mortality was observed.

Mortality:

- No mortality was observed.

Clinical signs:

other: - Animals were ruffled and depressed within 2 h after dosing but were normal after 24 h.

Gross pathology:

- No abnormalities were noted at necropsy.

Other findings:

None

None

Interpretation of results:

GHS criteria not met

Conclusions:

Oral LD50 Combined > 5000 mg/kg bw

Executive summary:

In an acute oral toxicity study (limit test) performed similarly to OECD Guideline No. 401, a group of Sherman-Wistar rats (5/sex) were administered a single oral dose of test material at 5000 mg/kg bw by gavage. Animals were observed for mortality and clinical signs daily for 14 days. Initial and final body weight of the animals were recorded and then necropsied for macroscopic observations.

No mortality was observed. Animals were ruffled and depressed within 2 h after dosing but were normal after 24 h. All animals showed expected gains in bodyweight over the 14-day study period. No abnormalities were noted at necropsy.

Oral LD50 Combined > 5000 mg/kg bw

Under the test conditions, the test material is not classified according to the annex VI of the Regulation EC No. 1272/2008 (CLP).

This study is considered as acceptable and satisfies the requirement for acute oral toxicity endpoint.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

The key study performed on the registered substance in rats was pre-guideline and pre-GLP, but was similar to OECD Test guideline No 401. This study was considered sufficiently robust to cover this endpoint.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 13 to 27, 1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Although conducted under worst-case conditions (abraded skin, occlusive dressing), no mortality was observed during this study. A repeat study is unlikely to show worse effects; therefore, this study was considered sufficiently robust to cover this endpoint.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

(abraded skin, occlusive dressing and 3 animals/sex used; no details on test animals and environmental conditions)

Principles of method if other than guideline:

Not applicable

GLP compliance:

no

Remarks:

(pre-GLP)

Test type:

standard acute method

Limit test:

yes

Species:

rabbit

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2-2.5 kg

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: Back
- % coverage: No data
- Type of wrap if used: Treated areas were covered with large gauze patches and an impervious material was wrapped snugly around the trunk of each animal.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No data, any excess material was removed.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Animals were observed for mortality and clinical signs daily for 14 days. Initial and final bodyweights of animals were recorded.
- Necropsy of survivors performed: Yes; gross necropsies were performed on all animals at the 14-day observation period.

Statistics:

None

Preliminary study:

Not applicable

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No mortality was observed.

Mortality:

- No mortality was observed.

Clinical signs:

other: - No clinical signs were observed.

Gross pathology:

- No abnormalities were noted at necropsy.

Other findings:

None

None

Interpretation of results:

GHS criteria not met

Conclusions:

Dermal LD50 Combined > 2000 mg/kg bw

Executive summary:

In an acute dermal toxicity study (limit test) performed similarly to the OECD guideline No. 402, the abraded skin of albino rabbits (3/sex) was occlusively exposed to undiluted test material for 24 h at dose of 2000 mg/kg bw. Animals were observed for mortality, clinical signs and body weight changes daily for 14 days and then necropsied for macroscopic observations.

No mortality or clinical signs were observed. No abnormalities were noted at necropsy.

Dermal LD50 Combined > 2000 mg/kg bw

Under the test conditions, the test material is not classified according to the annex VI of the Regulation EC No. 1272/2008 (CLP).

This study is considered as acceptable and satisfies the requirement for acute dermal toxicity endpoint.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The key study performed on the registered substance in rats was pre-guideline and pre-GLP, but was similar to OECD Test guideline No 402. This study was considered sufficiently robust to cover this endpoint.

Additional information

Acute toxicity: oral

A key study was identified (Biosearch, 1979, rel.2). This study was non-GLP, but was similar to OECD Test guideline No 401.

Group of rats (5/sex) were administered a single oral dose of test material at 5000 mg/kg bw by gavage. Animals were observed for mortality and clinical signs daily for 14 days. Initial and final body weight of the animals were recorded and then necropsied for macroscopic observations.

No mortality was observed. Animals were ruffled and depressed within 2 h after dosing but were normal after 24 h. All animals showed expected gains in bodyweight over the 14 -day study period. No abnormalities were noted at necropsy.

Oral LD50 Combined > 5000 mg/kg bw.

Acute toxicity: dermal

A study was identified (Biosearch, 1979, rel.2). This study was non-GLP, but was performed similarly to the OECD guideline No. 402. The abraded skin of albino rabbits (3/sex) was occlusively exposed to undiluted test material for 24 h at dose of 2000 mg/kg bw.

No mortality or clinical signs were observed.

No abnormalities were noted at necropsy.

Dermal LD50 Combined > 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
Only one study available

Justification for selection of acute toxicity – inhalation endpoint
In accordance with Column 2 of REACH Annex VIII, in addition to the oral route (8.5.1), for substances other than gases, the information mentioned under 8.5.2 (acute toxicity by inhalation) and 8.5.3 (acute toxicity by the dermal route) shall be provided for at least one other route. The choice for the second route will depend on the nature of the substance and the likely route of human exposure
In the present case, inhalation exposure will be lower than dermal exposure because the registered substance has a low vapour pressure (15.4 Pa at 25°C) and a low freezing point (< -20°C), so the potential for the generation of inhalable forms is low. Dermal exposure is the more likely route of exposure based on physico-chemical properties (Log Kow = 3.3 at 20°C, WS = 278.8 mg/L at 20°C).

Justification for selection of acute toxicity – dermal endpoint
No study was selected since a weight-of-evidence approach was followed.

Justification for classification or non-classification

Harmonized classification:

The substance has no harmonized classification according to the Regulation (EC) No. 1272/2008.

Self-classification:

Acute toxicity via Oral route:

Based on the available data, the substance is not classified according to the Regulation (EC) No. 1272/2008 as the LD50 is greater than 2000 mg/kg bw.

Acute toxicity via Dermal route:

Based on the available data, the substance is not classified according to the Regulation (EC) No. 1272/2008 as the LD50 is greater than 2000 mg/kg bw.

Acute toxicity (Inhalation):

No data was available.

Specific target organ toxicity: single exposure (Oral):

The classification criteria according to the Annex VI of the Regulation (EC) No. 1272/2008 as specific target organ toxicant (STOT) – single exposure, oral are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value (oral) for a Category 1 classification (C≤ 300 mg/kg bw) and at the guidance value (oral) for a Category 2 classification (2000 mg/kg bw≥C > 300 mg/kg bw). No classification is required.

The criteria for Transient Organ effects (STOT-SE Category 3) according to Annex VI of the Regulation (EC) No. 1272/2008 are not met since narcotic effects were not observed in the acute oral toxicity study.

Specific target organ toxicity: single exposure (Dermal):

The classification criteria according to the Annex VI of the Regulation (EC) No 1272/2008 as specific target organ toxicant (STOT) – single exposure, dermal are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value (dermal) for a Category 1 classification (C≤ 1000 mg/kg bw) and at the guidance value (dermal) for a Category 2 classification (2000 mg/kg bw≥C > 1000 mg/kg bw). No classification is required.

The criteria for Transient Organ effects (STOT-SE Category 3) according to Annex VI of the Regulation (EC) No. 1272/2008 are not met since narcotic effects were not observed in the acute dermal toxicity study.

Specific target organ toxicity: single exposure (Inhalation):

No data was available. However, the registered substance is not a skin or an eye irritant, therefore respiratory tract irritation is not expected.