Application of a Building Management System to Automate a 90-Day Chloroform Inhalation Study

Abstract

An inhalation exposure study typically requires significant personnel time to control the temperature, relative humidity, air flow, and concentration of the test compound in an inhalation chamber. Static pressure, light cycles, sampling sequence, and other variables may also be controlled. We report on the automation of a whole-body inhalation system using a building management system. The existing building environmental management system (Infinity, Andover Controls, Andover, MA, USA) at the Chemical Industry Institute of Toxicology (CUT) was adapted to control the whole-body inhalation facility. Among the features offered by this system are feedback control of exposure parameters, automatic logging of data and user activity, report writing capability, multilevel password security to limit access, simple scheduling procedures, simple programming language, and distributed computer system. A 90-day exposure to chloroform was completed at 0.3, 2, 10, 30, 90, and 300 ppm using the adapted building management system. In this study, daily exposures were started between 2:30 and 4:00 a.m. and ended between 8:30 and 10:00 a.m. The chloroform exposures were conducted 7 days a week. Average concentration of the test atmosphere was maintained within 2% of the target concentration. Temperature, relative humidity, airflow, and static pressure were also maintained to within a few percent of their set points. Use of a building management system provides a means of automating inhalation exposures, thereby permitting the conduct of complex studies with minimal supervision.

Key Words: :

• automated control
• building management system
• chloroform
• inhalation exposure