19. FLOOR, WALL, GROUND-OPENING AND ROOF EDGE 37
20. PORTABLE LADDERS 38
21. RADIOGRAPHY 38
22. WELDING AND CUTTING 39
23. COMPRESSED GAS BOTTLES 40
24. ELECTRICAL 41
25. ELECTRICAL POWERED TOOLS AND OTHER POWERED TOOLS 43
26. MEASURES FOR PROTECTION FROM ELECTRIC SHOCK 44
27. HIGH PLACE