SYMPOSIA PAPER Published: 01 January 1996

Measurement of Human Eye Irritation Using a CO Reference Scale


This paper describes a combined system for human eye exposure and sensory evaluation. The system was developed as part of a research program which is focused on development of biological response models to be used for prediction of the potential of emissions from building materials to cause sensory irritation in the indoor environment. The method described in this paper measures air pollutants potential to cause sensory eye irritation using a master scale (the sensory irritation caused by the emissions are measured in terms of concentration of a reference irritant). The purpose of this study was to test the exposure equipment, the exposure procedure, the evaluation procedure, and the statistical method. The principle of the combined system is that subjects compare the intensity of sensory irritation in one eye which is exposed to polluted air with the intensity of sensory irritation in the other eye, which is exposed to a reference gas. This left-right eye comparison was chosen because it is quicker to perform than having subjects first exposed to the pollutant gas bilaterally and afterwards exposed to the reference gas bilaterally. Moreover, by making the comparison simultaneously, the subject does not have to remember the impression of the previous exposure. In this study, CO2 was used both as a simulation of the air pollution and as the reference gas. CO2 was chosen as reference irritant because it is the most studied compound in relation to eye irritation, it is easy to work with, and the short term feeling of irritation is reversible and without any risk to the subjects. Using the same irritant as pollutant and reference irritant makes it possible both to test the combined system in an easy way and, at the same time, to investigate whether subjects perceive the same sensory irritation in the two eyes, when their eyes are exposed to equal concentrations of an irritant. Twelve healthy subjects participated in the study. All subjects were exposed to four concentrations of the polluted air (CO2) in one eye, while the other eye was exposed to different concentrations of the reference gas (CO2). The statistical analysis showed that using this exposure system, subjects were able to identify equal exposure concentrations in the two eyes. With further development of the response method, it may be possible from the eye irritation data to predict the potential of a source to cause sensory irritation in a full-scale indoor environment and to use the system as a reference method for other biological models.

Author Information

Hempel-Jørgensen, A
Aarhus University, Aarhus C, Denmark
Kjaergaard, SK
Aarhus University, Aarhus C, Denmark
Mølhave, L
Aarhus University, Aarhus C, Denmark
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: D22
Pages: 350–366
DOI: 10.1520/STP15632S
ISBN-EB: 978-0-8031-5340-0
ISBN-13: 978-0-8031-2030-3