“…Although wearing respirators may be necessary, the side effects associated with their use limits their effectiveness or acceptability in most cases. Factors associated with PPE use have been identified [Akbar-Khanzadeh et al, 1995;Pontrelli, 1997] and may be grouped into: (a) physical factors, such as weight, color, visual and communication impairment-for instance, fullface respirators are known to cause visual field loss [Zelnick et al, 1994]; (b) physiological factors, such as an increase in metabolic rate and a decrease in dissolved blood oxygen [Johnson et al, 1995]; (c) psychological factors, such as claustrophobia and lack of perceived need; and (d) financial factors, such as the cost of original purchase and maintenance [Popendorf et al, 1995;Young et al, 1998]. …”