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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
10/1987 to 01/1989
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-study according to OECD guideline

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Principles of method if other than guideline:
Method: other: Protocol guideline not specified in report. However, protocol meets criteria specified in OECD 403 "Acute Inhalation Toxicity."
GLP compliance:
yes (incl. certificate)
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Propylene Glycol n-Butyl Ether
- Physical state: colorless liquid
- Analytical purity: 98%
- Lot/batch No.: XZ 95410.00

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratory, Kingston, NY
- Age at study initiation: 11 weeks
- Weight at study initiation: ca. 150 g (females) and ca. 240 g (males)
- Fasting period before study: none
- Housing: 2 per cage in suspended stainless steel wire mesh cages
- Diet (e.g. ad libitum): ad libitum except during exposure
- Water (e.g. ad libitum): ad libitum except during exposure
- Acclimation period: 4 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 25°C (during exposure)
- Humidity (%): 48% (during exposure)
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: none
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rochester-type stainless steel and glass exposure chambers under dynamic air flow conditions
- Exposure chamber volume: 112 liter
- Source and rate of air: 30 l/min
- Method of conditioning air: Vapors of PnB were generated using a glass J-tube method. Liquid test material was metered into the J-tube. Compressed air, heated with a flameless torch (FHT-4, Master Appliance, Racine, WI) to the minimum extent necessary, passed through the J-tube to volatilize the test material.
- Treatment of exhaust air:
- Temperature, humidity: 25°C, 48%

TEST ATMOSPHERE
Air flow through each chamber was determined with a rotameter. The rotameter was calibrated with an AL-1400 gas meter prior to the start of the study. The temperature in the chamber was controlled by a system designed to maintain temperature at approximately 22°C. Temperature, air flow and relative humidity values were recorded every 30 minutes during the four-hour exposure period.
The analytical concentration of PnB in the breathing zone of the animals was determined by gas chromatography using a flame ionization detector. The gas chromatographic conditions were as follows: helium flow = 30 ml/min, hydrogen flow = 30 ml/min, air flow = 300 ml/min, oven = 110°C and detector = 180°C. A 6 foot x 1/8 inch stainless steel column packed with 10% OV-101 on 100/120 mesh Chromosorb WHP was used for separation of the test material from air. The gas chromatographwas calibrated with air standards of PnB which were prepared by injecting measured volumes of PnB into SARAN bags containing measured volumes of dry, compressed air.
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
651 ppm
No. of animals per sex per dose:
5
Control animals:
not specified
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for overt signs of toxicity during the exposure period (day 1) and after for 14 additional days.  Rats were weighed prior to exposure and on days 2, 4, 8, 11 and 15.
- Necropsy of survivors performed: yes (including examination of the eyes)
- Other examinations performed: clinical signs, body weight, ophthalmological examination, behaviour pattern and nervous system activity
Statistics:
Means and standard deviations of animal body weights, chamber temperatures, relative humidities, and chamber air flows were calculated for descriptive purposes.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC0
Effect level:
> 651 ppm
Exp. duration:
4 h
Mortality:
no deaths
Clinical signs:
other: No clinical signs were observed either during the exposure or throughout the subsequent two-week observation period.
Body weight:
Body weights appeared normal during the observation period.
Gross pathology:
Gross pathologic examination at the end of the two-week observation period revealed no treatment-related lesions.
Other findings:
none

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The LC0 is greater than 651 ppm: no EU classification for acute inhalation toxicity.
Executive summary:

A single group of Fischer 344 rats (5/sex) was exposed in whole-body inhalation chambers for 4 hours to vapors of propylene glycol n-butyl ether at a measured concentration of 651 ppm.  Chambers were 112 liters in volume and airflow was 30 liters/min.  Animals were observed for overt signs of toxicity during the exposure period (day 1) and after for 14 additional days.  Rats were weighed prior to exposure and on days 2, 4, 8, 11 and 15.

No rats died when exposed to 651 ppm propylene glycol n-butyl ether for 4 hours.  No signs of toxicity during or after exposure were noted and no lesions were observed at necropsy except for a unilateral distension of the ovarian
bursa in one female.  This lesion was considered unrelated to exposure since it occasionally occurs in unexposed
females.

The highest attainable concentration of PnB under ambient conditions of exposure was not toxic to rats following a single four-hour exposure. Therefore, the potential for acute inhalation toxicity is very low for this material.