Cyclopentanone

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Purity of the test substance was not reported even if the cyclopentanone was received from Esso Research and Engineering and was considered to be free from impurities. The study was performed before the GLP standard was established. However, the method and the results were quite well described. The exposure chamber concentrations were nominal dosage concentrations. The LC50 was estimated because mortality data were not suitable for statistical analysis.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1965

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

GLP compliance:

no

Test type:

other: no data

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cyclopentanone

EC Number:

204-435-9

EC Name:

Cyclopentanone

Cas Number:

120-92-3

Molecular formula:

C5H8O

IUPAC Name:

cyclopentanone

Details on test material:

Cyclopentanone from Esso research and Engineering Company
- Test material identity: Cyclopentanone (MRD-64-20)
- Details on test material: no other information are available

Test animals

Species:

rat

Strain:

Wistar

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS:
- Weight at study initiation: 200 - 225 g
- Housing: Animals were housed in wiremesh cages centred in the
stainless steel exposure chamber.
- Source, age at study initiation, fasting period before study, diet, water, acclimation period: data not available

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

IN-LIFE DATES: data not available.

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
inhalation exposure to vapours was carried out in a dynamic, 500 litres, stainless steel exposure chamber.
Vaporization of the cyclopentanone was achieved by means of delivering predetermined amounts of the liquid test substance by a metering pump
into a stainless steel spray nozzle tip operating under positive air pressure.
The cyclopentanone metered through the nozzle were then vaporized by the pressurized air flow directly into the exposure chamber.
Nominal dosage concentrations were calculated from the amount of liquid being metered and the total airflow through the chamber.

TEST ATMOSPHERE: data not available

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

4 h

Concentrations:

4.7, 12, 15, 17.8, 19.5 mg/L

No. of animals per sex per dose:

10 male rats per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: mortality and signs of toxicity were observed at half-hour intervals during the actual exposure and daily during a 14-day post-exposure observation period.
- Necropsy of survivors performed: yes

Statistics:

no data available

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC50

Effect level:

>= 19.5 mg/L air

Exp. duration:

4 h

Remarks on result:

other: 95% CL: results not suitable for statistical analysis

Mortality:

Groups of animals were exposed to test concentrations of 4.7, 12, 15, 17.8 or 19.5mg/L, resulting in the following cumulative mortality data
(no. animals dead/no. animals tested): 0/10, 1/10, 3/10, 3/10 and 4/10, respectively.
All animals survived the exposure period, with deaths occurring during the 14 day observation period.

Clinical signs:

other: During exposure, dyspnea, depression and decreased activity were observed. Moreover, ataxia and prostration were also noted at the two highest levels. These signs disappeared within 48 hours.

Body weight:

no data available

Gross pathology:

Autopsy of dead animals showed moderate congestion of the lungs, liver and kidneys. No gross findings were noted from autopsies at the end of the study.

Any other information on results incl. tables

Copy of Exxon's submission to EPA of test data on Isophorone & cyclopentanone. LC50 studies in rats were reported.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this study, no mortality were observed in male rats at 4.7, 12, 15 mg/L of cyclopentanone.
Three and 4 rats died respectivelly after 17.8 and 19.5 mg/L.

Executive summary:

In an acute inhalation toxicity study (Anon., 1965), groups of Wistar rats (10 males/group) were exposed by inhalation (whole body) to cyclopentanone (purity unknown) for 4 hours at concentrations of 4.7, 12, 15,n 17.8, 19.5 mg/L. 

Animals then were observed for 14 days.

No mortality were observed in male rats at 4.7, 12, 15 mg/L of cyclopentanone. Three and 4 rats died respectivelly after 17.8 and 19.5 mg/L.

Based on these results a LC50 for male rats was identified. LC50 (male rats) >= 19.5 mg/L

Cyclopentanone is classified as being of LOW Toxicity based on male results.