Cyclopentane, methoxy-

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2002-12-16 to 2003-02-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

1981

Deviations:

no

GLP compliance:

yes

Test type:

traditional method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

445-090-6

EC Name:

-

Cas Number:

5614-37-9

Molecular formula:

C6 H12 O

IUPAC Name:

Cyclopentyl methyl ether

Test material form:

liquid

Specific details on test material used for the study:

Lot No.: 020618
Purity: 99.99%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories
- Females nulliparous and non-pregnant: yes
- Age at study initiation: Approximately 8 weeks
- Weight at study initiation: MaIe: 277 - 319 g; Female: 210 - 233 g
- Housing: group housed (2-6/cage) during acclimation, and then individually in suspended stainless steel wire mesh cages during the study.
- Diet: Certified Rodent Diet, No. 5002; (Meal), available without restriction
- Water: available without restriction via an automated watering system
- Acclimation period: approximately 1 week.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 to 23°C
- Humidity (%): 13 to 69%
- Photoperiod (hrs dark / hrs light): twelve-hour light/dark cyde controlled via an automatic timer

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

other: nitrogen

Mass median aerodynamic diameter (MMAD):

>= 1.204 - <= 3.775 µm

Geometric standard deviation (GSD):

> 1.649 - <= 2.342

Remark on MMAD/GSD:

Group 1 - 10.5 mg/L: Mean MMAD: 2.334 µm, mean GSD: 1.891
Group 2 - 21.5 mg/L: Mean MMAD: 2.149 µm, mean GSD: 1.896

Details on inhalation exposure:

- Pre-Study Trials: Trials were performed to evaluate the optimal set of conditions and equipment to generate stable atmospheres at the targeted exposure level.
- Chamber Operation:
The flow-past nose-only exposure chamber was operated at a flow rate of 10 Liters per minute. The final airflow was set to provide at least one air change in 5.0 minutes (12 air changes/hour) and a T99 equilibrium time of approximately 3 minutes. The T 99 equilibrium time was added to the 4 hours; i.e., the atmosphere was generated for 4 hours and T 99 minutes. This chamber size and airflow rate is considered adequate to maintain the oxygen level at least 19%. The chamber was exhausted via a 1" tubing through the in-house filtering system, which consisted of a coarse filter, a HEPA filter and an activated charcoal bed. The nose-only exposure chamber was contained within a 10 m3 chamber.
At the end of the exposure, all animals remained in chamber for a minimum of 30 minutes. During this time the chamber was operated at the same flow rate as used during the exposure using clean air only.
Recordings of total chamber flow and static pressure were made every half-hour during the exposure.
- Environmental conditions: Temperature: 20 to 23°C, Relative Humidity 17 to 23%

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Group 1: 10 mg/L (Trarget)
Group 2: 20 mg/L (Trarget)

No. of animals per sex per dose:

5 animals per sex per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Viability Checks: observed for mortality and general condition twice daily (once in the morning and once in the afternoon).
- Physical Examinations: Day 0 (Day of Exposure): Animals were observed individually prior to exposure, as a group, at fifteen minutes intervals during the first hour of exposure, and hourly for the remainder of the exposure. They were observed individually upon removal from the chamber and hourly for two hours post -exposure. Days 1 – 14: once daily.
- Body Weights: Weighed on Day 0 (prior to exposure), Days 7 and 14 (prior to termination).
- Necropsy: All survivors were euthanized by exsanguination following carbon dioxide inhalation at termination on Test Day 14.
- Macroscopic Examinations: Complete macroscopic postmortem examinations were performed on all animals.

Statistics:

No statistical analysis was performed.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 21.5 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

All animals survived

Clinical signs:

other: There were no signs of toxicity noted during the exposure periods. Clinical signs of toxicity noted immediately following the 10.5 mg/L exposure included lacrimation and red nasal discharge. Clinical signs of toxicity noted immediately following the 21.5

Body weight:

AlI animals gained weight during both weeks of observations after both exposures.

Gross pathology:

There was no effect of treatment evident from the macroscopic postmortem observations of the test animals from both exposures. All animals were within normallimits.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was considered to be relatively non-toxic to rats by nose-only inhalation exposure with a 4-hour LC50 greater than 21.5 mg/L (analytical) for males and females.