2,2'-oxydiethanol

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Inhalation of Aerosolized Ethylene Glycol by Man

Author:

Wills J.H.

Year:

1974

Bibliographic source:

CLINICAL TOXICOLOGY 7( 5), pp. 463-476 ( 1974)

Materials and methods

Endpoint addressed:

respiratory irritation

repeated dose toxicity: inhalation

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Twenty volunteers were exposed during 20 to 22 hr per day to aerosolized ethylene glycol in mean daily concentrations between 3 and 67 mg/m3.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Ethane-1,2-diol

EC Number:

203-473-3

EC Name:

Ethane-1,2-diol

Cas Number:

107-21-1

Molecular formula:

C2H6O2

IUPAC Name:

ethylene glycol

Method

Ethical approval:

not applicable

Details on study design:

Twenty volunteers were exposed during 20 to 22 hr per day to aerosolized ethylene glycol in mean daily concentrations between 3 and 67 mg/m3 in an unused ward of a prison hospital. Fourteen other volunteers, as a control group, were kept in another ward of the prison hospital facility and were fed and otherwise treated as similarly as possible to the exposed group.
The volunteers left this chamber only for meals and toilet purposes; they spent at least 20 hr each day within the chamber, and more commonly about 22. Moderate smoking within the chamber was permitted.
Both the control and the exposed groups were held under their particular experimental conditions for 30 days. Follow-up observations were made on both groups two weeks after the end of the exposure period. Before admission to the study, all subjects underwent complete physical examinations, including slit-lamp, electrocardiographic, and electroencephalographic studies. A battery of psychological tests designed to reveal effects on simple reaction time, reaction time with discrimination, visual-motor coordination, perception, and mental ability was applied also. These examinations were repeated at the end of the first two weeks of exposure in the main study and at the termination of the exposure. Blood and urine samples were collected and examined.

Exposure assessment:

measured

Details on exposure:

An unused ward of the prison hospital was converted into an exposure chamber.
Aerosol jet nozzles were mounted to force mists ol ethylene glycol into the cooled air streams of the three air conditioners. Air compressed to 50 psi was supplied to the jet nozzles through pipelines from a compressor in an adjacent room. The ethylene glycol was aspirated from reservoirs below each nozzle; these reservoirs were refilled by hand as necessary.
The sizes of the droplets of the aerosol were estimated at intervals by exposing three clean glass slides simultaneously in various parts of the chamber. These slides were stored in a moist chamber until they could be examined. The diameters of the droplets were measured with a calibrated microscope, and were found always to be within the range 1-5 μm.

Polyethylene bottles of 250 ml capacity were evacuated by a motor driven pump and were then allowed to fill with air from the room, the cycle of evacuation and filling being repeated 15 times. Samples were collected during each of the three periods during the day at which the volunteers left the chamber to eat. Samples were collected from five stations within the chamber at each sampling time.
For estimation of the ethylene glycol within the bottle, 2 mL of distilled water were injected into the bottle with a syringe and needle. The bottle was then shaken vigorously for several minutes; an aliquot of the aqueous solution was analyzed calorimetrically. The concentrations of ethylene glycol measured within the five air samples collected at each sampling time were averaged, the means for the three sampling times being averaged to obtain a mean daily value. The daily means were averaged to obtain mean weekly or fortnightly values.

Results and discussion

Results:

The results of intensive exposure for four weeks to aerosolized ethylene glycol were satisfactorily negative. No evidence was found that a tolerable concentration during virtually uninterrupted exposure for that length of time had any deleterious effect on psychologic or other functions of the human body. The subject who consistently excreted the highest mean concentration of the glycol in his urine (18 mg/100 mL) may be calculated to have absorbed about 0.8 g/day. On the assumption that man excretes unchanged about one-quarter of that which is absorbed. This would represent between 1 and 2 % of the estimated Single lethal dose.
The most common complaint during the exposure was irritation of the upper respiratory tract. This symptom of exposure to ethylene glycol seemed to correlate well with the concentration of the glycol in the ambient air. Concentrations of about 200 mg/m3 or more were intolerable due to strong irritation of the upper respiratory tract, with a burning sensation along the trachea and a burning cough. On the basis of this study, we judge that it would be impossible for an individual with reasonably normal sensory apparatus to absorb through his respiratory tract enough aerosolized ethylene glycol to cause damage to any important functional systems or organs.