An apparent advantage of specifying classes of safety behaviors, rather than every instance or occurrence of a specific behavior, is the potential for influencing a large set of safetyrelated behaviors efficiently. A potential disadvantage of specifying several classes of safety behaviors is that influence over any one specific instance of behavior might be limited and attention might be directed toward behaviors that do not currently pose a risk. It is perhaps more effective and efficient to differentiate safety-related behaviors according to whether they have led to injuries in the past versus only those classes of behavior that have recently caused injuries (Komaki et al., 1978; Sulzer-Azaroff & Santamaria, 1980).