*Possibility = A < D,① < ④
A = Surrounded by safety cover and difficult to enter dangerous zone
B = Safety cover exists, but so do inadequacies such as low rail; may come in contact with dangerous area if ones pushes it
C = No safety cover, but has emergency stop equipment
D = No safety cover plus inadequacies in such areas as warning and display

① = Minimal injury
② = Light injury
③ = Serious injury (including inability to work)
④ = Critical injury (including death)

Bridgestone Tire Japan, improved safety guard example*

* Prevention of accidents in case workers enter the conveyer area or the next-stage conveyer, either in operation or in waiting status.