In spite of the substantial repository of literature about respirators, little is known about the practicalities of their use. The focus of this research was about the practical aspects of using respirators in New South Wales workplaces. Two self-administered postal surveys were used to assess the level of implementation of respirator programs in 1996 and 2001. After five years, six elements improved. The most improvement was seen in the area of documentation including written procedures, keeping training records, recording respirator tasks, and maintenance records. The second survey investigated respirator maintenance and found little automated cleaning. Thorough washing was scarce with more than 50% of organisations relying on moist towelettes. For the third portion of the research methodology 485 used, half facepiece reusable respirators from 36 different sites were examined to determine the most common respirator defects. Maintenance and cleaning procedures were primitive and probably inadequate. Disinfection or sanitisation was common practice indicating concern about infectious diseases. The 2001 survey found that physical inspection of respirators in the workplace usually checked for the common types of defects found in the examination of used respirators. Weight, breathing resistance, heat and tightness were reported as causes of discomfort. The key outcomes from the research were that respirator programs were poorly implemented in a group of organisations that were expected to have more expertise than most and that the most common defects could be corrected by good respirator cleaning programs. / Doctor of Philosphy (PhD)