Oxydipropanol

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, available as unpublished report, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 81-3 (Acute inhalation toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Oxydipropanol

EC Number:

246-770-3

EC Name:

Oxydipropanol

Cas Number:

25265-71-8

Molecular formula:

C6H14O3

IUPAC Name:

1,1-Oxydi-2-Propanol

Details on test material:

- Name of test material (as cited in study report): dipropylene glycol
- Physical state: clear viscous liquid
- Analytical purity: 100%
- Lot/batch No.: TB41213-04-2
- Supplier: Regwest Company
- Storage condition of test material: in the original container (blue metal can) at room temperature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: bred in the laboratory colony (Branchville)
- Age at study initiation: approximately 8 weeks of age
- Weight at study initiation: males 242 to 269 grams; females 189 to 209 grams.
- Fasting period before study: no data
- Housing: individually housed in wire cages under laboratory conditions in the study room
- Diet (e.g. ad libitum): Agway NIH-31M Rodent Diet or equivalent.
- Water (e.g. ad libitum): potable municipal water ad libitum
- Acclimation period: 5 days


ENVIRONMENTAL CONDITIONS
- Temperature: 68-74ºF
- Humidity (%): 35-65%
- Photoperiod (hrs dark / hrs light): 12 hours on/12 hours off cycle

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other:

Details on inhalation exposure:

Each chamber used was made of plexiglass, and measured approximately 50.5 cm long x 29.5 cm high (semi-cylindrical), having a volume of 47.4 liters. A wire mesh floor was raised 5.0 cm from the floor of the chamber and on this the rats were individually caged in all wire-mesh cages. The total "volume" of the test animals was not more than 5% of the volume of the test chamber based on a 1:1 equivalence between body volume (ml) and body weight (g). On one side near the top of the exposure chamber was a portal through which the test substance and air flow were introduced, and at the opposite side near the bottom there was a portal for exhaust to which a vacuum pump was attached. Test substance generation was established and maintained from the DeVilbiss Glass Nebulizer by using a Gast Air Pump supplying air at a measured pressure. The test substance was delivered from the nebulizer which was maintained at the portal of the exposure chamber. The vapor or inlet tube was set to deliver the aerosol directly through the portal into the exposure chamber. In addition to the four hour exposure period, a period of time (t99) was allowed to compensate for the time required for delivery system stabilization to a nominal chamber concentration greater than 5 mg of test substance per liter of air or to the maximum concentration of aerodynamic particles at the "limit dose".
The time for stabilization of the system was determined by the formula t99 = 4.605 x a/b, where t99 = time required to reach 99% of desired concentration; a = volume of chamber (liters), b= flow rate through the chamber (l/min).

Analytical verification of test atmosphere concentrations:

yes

Remarks:

thrice by gravimetric measurement

Duration of exposure:

4 h

Concentrations:

Mean 2.34 mg/ in the breathing zone

No. of animals per sex per dose:

5/sex/dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Observations: animals were observed from outside the chamber for mortality and pharmacotoxic signs hourly during the exposure period. Rats were observed immediately following the t99 period after they had been returned to standard cages and then at approximately 1, 3 and 5 hour following the exposure, and once daily thereafter. In addition, mortality was checked each afternoon (except weekends and holidays) for the remainder of the 14 day observation period.
- Weighing: was obtained on day 0 (before dosing) and on days 2, 3, 4, 7 and 14.
- Necropsy of survivors performed: yes. A postmorten examination of each animal was carried out with detailed examination of the nasal air passages, trachea, bronchii and lungs. Additionally, the gross necropsy included but was not limited to the following organs: heart, spleen, liver, adrenals, kidneys, urinary bladder, stomach, small intestine, large intestine and reproductive organs. Sections from the lungs and other parts of the respiratory tract exhibiting evidence of specific pathology related to test substance administration were retained in 10% buffered formalin until all rats had undergone necropsy. Unless histopathology of these tissus was considered essential to interpretation of the results, the preserved tissues were discarded.

Statistics:

None used

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.34 mg/L air

Exp. duration:

4 h

Mortality:

There were no deaths

Clinical signs:

other: Control rats remained normal in appearance and behavior during exposure and during the subsequent 14-day observation period. Rats exposed to the test substance remained normal during the exposure period except for "wetting' of the fur due to deposition of

Body weight:

All exposed rats had a similar body weight gain compared to controls during the study.

Gross pathology:

Neither in the control group nor in the group exposed to the test substance were there any pathognomonic findings. All organs and tissues examined grossly, including the respiratory tract, appeared normal.

Any other information on results incl. tables

In rats exposed to the maximum attainable concentration of 2.34 mg/l of the test substance during a 4 -hour period there was no mortality. At this exposure level, rats appeared normal throughout the study.