It is a well-established finding that the vast majority of occupational injuries and fatalities are caused by unsafe work behavior or human errors (Freeman, 1972; Hale and Glendon, 1987; Krause, 1995; Lutness, 1987; Petersen, 1988; Salminen and Tallberg, 1996; Shuckburgh, 1975; Surry, 1971; Williamson and Feyer, 1990). Heinrich (1931) conducted case studies of 75,000 accident records and found that 88 percent of all industrial accidents were primarily caused by unsafe acts of persons whereas 10 percent by unsafe conditions. Heinrich's finding was affirmed by several researchers in the 1980s and 1990s.
Williamson and Feyer (1990) found that 91 percent of all the occupational fatalities that occurred in Australia for the years 1982 to 1984 involved behavioral factors. Another similar finding was made by Salminen and Tallberg (1996) who reported that 84 - 94 percent of all the fatal occupational accidents (for the years 1985. 1990) and serious accidents (in 1988 and 1989) in Finland were mainly caused by human errors. Lutness (1987) also supported this, reporting that more than 95 percent of all accidents involved human errors.
As unsafe work behavior has been noted as the main cause of accidents, many researchers have conducted studies that examined contributory factors to unsafe work behavior. This paper will discuss the major contributory factors to unsafe work behavior based on a comprehensive and thorough review of the past 30 years. literature and address the structural relationships among contributory factors to unsafe work behavior using structural equation modeling (SEM), a statistical technique that allows assessment of both direct and indirect effects of each latent factor on other latent factors (Maruyama, 1998).
Up to the 1980s, a lot of safety efforts had been primarily focused on technical actions and effective safety management in order to prevent occupational injuries and fatalities (Hale et al., 1998; Hale and Hovden, 1998; Petersen, 1988). Those injury prevention activities were basically based upon a credo of dichotomous etiology of accidents--unsafe acts and unsafe conditions. However, investigations of several major industrial disasters in the 1980s showed that the root causes involved more than technical or human failures. (Hale et al., 1998, p. 4). It is organizationaland cultural factors that underlay disasters in high technology industries (IAEA, 1986; Turner and Pidgeon, 1997; Weick et al., 1999). While the vast majority of accidents are still caused by unsafe behavior, research has shown that organizational and cultural factors considerably affect unsafe work behavior (Brown et al., 2000; Hofmann and Stetzer, 1996; Oliver et al., 2002; Petersen 1988; Thompson et al., 1998; Tomas et al., 1999).