Propane-1,3-diol

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:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

PDO from chemical process.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Six male rats were exposed nose-only for a single 4-hour period to 1,3-propanediol aerosol in air. Rats were weighed and observed for clinical signs of toxicity during a 14-day observation period.

GLP compliance:

no

Test type:

other: Inhalation Approximate Lethal Concentration

Test material

Test material information

Constituent 1

Reference substance name:

Propane-1,3-diol

EC Number:

207-997-3

EC Name:

Propane-1,3-diol

Cas Number:

504-63-2

Molecular formula:

C3H8O2

IUPAC Name:

propane-1,3-diol

Details on test material:

- Physical state: liquid
- Purity: >99%
- Stability under test conditions: The test substance was expected to be stable throughout the exposure phase of the study.

Test animals

Species:

rat

Strain:

other: Crl:CD(SD)BR

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Raleigh, North Carolina
- Age at study initiation: approximately 8 weeks
- Weight at study initiation: 239 to 307 grams
- Housing: Housed either singly or in pairs in suspended, stainless steel, wire-mesh cages
- Diet: Certified Rodent Chow #5002, ad libitum
- Water: Tap water from United Water Delaware, ad libitum
- Acclimation period: Rats were quarantined after arrival for at least 6 days prior to testing.

ENVIROMENTAL CONDITIONS
- Temperature (°C): 23±2
- Humidity (%): 50±10
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12-hour light/12-hour dark.

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

other: air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Spraying Systems Nebulizer with a Harvard Model 22 Syringe Infusion Pump.
- Exposure chamber volume: 29-L
- Method of holding animals in test chamber: Individually restrained in perforated stainless steel cylinders with conical nose pieces
- Source and rate of air: Filtered Houseline Air and 15 L/min
- Method of conditioning air: chamber airflow was set at the beginning of each exposure and adjusted to maintain desired atmospheric concentration. Airflow was monitored continually with a Brooks model 1355 Sho-Rate Rotometer. Temperature, relative humidity, and oxygen were measured two times during the exposure.
- System of generating particulates/aerosols: Polycarbonate dispersion plate located near the chamber inlet was used to promote uniform aerosol distribution throughout the chamber.
- Method of particle size determination: Gravimetric Analysis (preweighed 25 mm Gelman glass fiber Type A/E filter. Weighed on a Cahn model C-30 Microbalance
- Treatment of exhaust air: Pair of liquid traps (water scrubbers) and MSA charcoal/HEPA filter cartridge
- Temperature, humidity, pressure in air chamber: 23±2°C, 48 to 54%

TEST ATMOSPHERE
- Brief description of analytical method used: Aerosol concentrations determined at 30-minute intervals by gravimetric analysis. Once air sample collected during exposure to determine particle size distribution with a Sierra Series 210 cyclone preseparator/cascade impactor and Sierra Series 110 Constant Flow Air Sampler.
- Samples taken from breathing zone: Yes. Known air volumes drawn from breathing zone through a filter cassette that contained a preweighed 25 mm Gelman glass fiber filter.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): MMAD = 3.2 µm GSD 2.1

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

5 mg/L

No. of animals per sex per dose:

6 male rats

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observed each day for mortality, and were weighted and observed for clinical signs of toxicity at least four times per week (weekends excluded unless warranted by the health status of the rats).
- Necropsy of survivors performed: no

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

other: ALC

Effect level:

> 5 mg/L air (analytical)

Exp. duration:

4 h

Mortality:

There were no mortalities for rats exposed to 5.0 mg/L.

Clinical signs:

other: During the exposure, no abnormal clinical signs were observed. Immediately following the exposure, when rats were removed from the chamber, all rats had wet fur/perineum, and one rat had an ocular discharge. No clinical signs of toxicity were observed i

Body weight:

Slight to moderate weight loss was observed in all rats one day following the exposure. Although one rat had transient body-weight loss during the remainder of the recovery, all rats experienced an overall weight gain by the end of the 14-day recovery period.

Any other information on results incl. tables

Mean Aerosol Concentration (mg/L)	Aerosol Size			Mortality
	MMAD (µm)	Geometric Standard Deviation	Percent < 10µm
5.0	3.2	2.1	94	0/6

Applicant's summary and conclusion

Conclusions:

The study and the conclusions which are drawn from it fulfill the quality criteria (validity, reliability, repeatability).

Executive summary:

Six male rats were exposed nose-only for a single 4-hour period to 1,3-propanediol aerosol in air. Rats were weighed and observed for clinical signs of toxicity during a 14-day recovery period. The approximate lethal concentration (ALC) was greater than 5.0 mg/L.