Chapter 2 Safety in Welding

1. Chapter 2Safety in Welding

2. Objectives Burn classifications and emergency treatment Dangers of types of light, and avoiding eye and ear injuries Use a chart to select eye and face protection Describe various types of respiratory protection Avoid dangerous fumes and gases

3. Objectives (continued) The purpose of Material Safety Data Sheets The benefits of recycling waste material General work clothing and special protective clothing Safely handle, secure, and store cylinders Protect against fire danger when welding

4. Objectives (continued) The importance of planned maintenance Tools commonly used by welders Good electrical safety practices Types of metal cutting machines Safely lift heavy assemblies Ladder safety

5. Introduction No substitute for caution and common sense Each person must take personal responsibility Welding has a number of potential safety hazards Most large welding companies have mandated safety classes

6. Burn Classification Burns are one of the most common and painful injuries Caused by ultraviolet light rays and contact with hot welding torches All burns must receive proper medical treatment Burns are divided into three classifications

7. First-Degree Burns The surface of the skin is reddish Tender and painful No broken skin Put the burned area under cold water or apply a cold compress Cover the area with sterile bandages Never apply butter or grease

8. Second-Degree Burns The surface of the skin is severely damaged Blisters and possible breaks in the skin Put the area under cold water or use cold water compresses Pat the area with a dry lint-free towel and cover with a sterile bandage Seek medical attention

9. Figure 2-2 Second-degree burn

10. Third-Degree Burns Surface of the skin appears white, charred Never remove any clothing Never put ice water or ice, ointments, sprays, etc. If the victim is on fire, smother the fire with a blanket, rug or jacket Cover the burn with a thick sterile dressing Call for an ambulance

11. Burns Caused by Light Some types of light can cause burns Three types of light include: Ultraviolet Infrared Visible Arc welding produces all three types of light Light from the welding process can be reflected from walls, ceilings, and floors

12. Ultraviolet Light The most dangerous Causes first and second degree burns to eyes or exposed skin The closer the welder is to the arc and the higher the current, the quicker a burn may occur A welder's eyes can receive a flash burn in seconds

13. Figure 2-6 The eye can be burned on the white or retina by ultraviolet light.

14. Infrared Light The light wave is felt as heat A person will immediately feel this type of light Burns can be easily avoided Protective action should be taken to cover yourself

15. Visible Light The light that we see Produced in varying quantities and colors May cause temporary night blindness Too little visible light may cause eye strain Visible light is not hazardous

16. Face Eye and Ear Protection Eye protection must be worn in the shop at all times Safety glasses with side shields Goggles Full face shield Flash glasses Welding light damage often occurs without warning

17. Welding Helmets Even with quality welding helmets, the welder must check for potential problems Undetectable leaks of ultraviolet light can cause a welder's eyes to itch or feel sore Ensure lens gasket is installed correctly Tape can be used as a temporary repair

18. Safety Glasses Adequate for general use Not suitable for heavy grinding, chipping, or overhead work Must be worn under an arc welding helmet at all times

19. Ear Protection Welding environment can be very noisy Hot sparks can drop into an open ear, causing severe burns Earmuffs cover the outer ear completely Earplugs fit into the ear canal Damage caused by high sound levels may not be detected until later in life – hearing will not improve with time

20. Respiratory Protection Welding and cutting produce harmful by-products Respirators protect against welding by-products Welders are responsible for following the shop's written respiratory protection policy Training should include: Proper use of respirator Maintenance schedules and respirator selection Procedures for testing the proper fitting and use Regular evaluation of the program

21. Equipment Some types of respiratory protection equipment: Air-purifying respirators Atmosphere-supplying respirators Demand respirators Positive pressure respirators Powered air-purifying respirators Self-contained breathing apparatus Supplied-air respirators

22. Fume Sources Paints, coating, or plating on metals can cause respiratory problems Before welding or cutting any painted metal, the surface must be cleaned Marine industry still uses lead-based paints Exposure to cadmium fumes can cause lung and kidney damage The best way to avoid problems is to provide adequate ventilation.

23. Vapor Sources Ozone gas is produced by ultraviolet radiation Ozone irritates mucous membranes The collection of fumes and gases can go unnoticed Concentrated fumes can cause a fire or explosion

24. Ventilation Welding area should be well ventilated Natural ventilationis best Forced ventilation may be required Large enough areas may not require forced ventilation

25. Figure 2-15 A room with a ceiling 16 ft. high may not require forced ventilation

26. Forced Ventilation Small shops or shops with many welders require forced ventilation Forced ventilation Can be general or localized Fixed or flexible exhaust pickups Forced ventilation is required when welding on metals that contain dangerous fumes

27. Material Safety Data Sheets Material safety data sheets (MSDS) provide details of possible hazards Often posted on a bulletin board or put in a convenient place where products are used If injured while using a product, take the material's MSDS when you seek treatment

28. Waste Material Disposal Welding shops generate a lot of waste materials All scrap metal can be recycled Hazardous waste materials include: Burned flux Cleaning solvents Dust collected in the filtration system Throwing hazardous material away is illegal

29. General Work Clothing Guidelines for work clothing: Shirts must be long-sleeved Pants must be long enough to cover the tops of the boots and must be without cuffs Boots must have high tops Caps should be thick Clothing must be free of frayed edges or holes There is no safe place to carry a butane lighter or matches while welding

30. Special Protective Clothing Extra protection is needed for each person who is in direct contact with hot materials Hand protection Body Protection Waist and Lap Protection Arm Protection Leg and Foot Protection Leather is often the best material to use

31. Handling and Storing Cylinders Store oxygen and fuel gas cylinders separately Store inert gas cylinders separately or with the same type of fuel cylinders Store all cylinders vertically Securely fasten the protective cap

32. Securing and Storing Gas Cylinders Secure cylinders with a chain or other device Chain cylinders attached to a manifold or stored in a special room Cylinder storage area must be away from halls, stairwells, and exits Storage areas should be away from heating units and welding sparks Secure storage areas from unauthorized people

33. Cylinders with Valve Protection Caps Must have the cap in place unless the cylinder is in use The cap prevents the valve from being broken off Never lift the cylinder by the safety valve When moving cylinders, the valve protection cap must be on All cylinders must be handled with care

34. General Precautions Any cylinders with a defect must be identified If a leak cannot be stopped Move cylinder to a vacant lot Slowly release pressure Post a warning sign Acetylene cylinders Must be upright for four hours before use Otherwise may draw acetone from the cylinder

35. Figure 2-25 Move a leaking fuel gas cylinder out of any work area

36. Fire Protection Fire is a constant danger Highly combustible materials should by 35 feet away from any welding site A fire watch can be provided by any person who knows how to sound an alarm The fire extinguisher must be the type required to put out a fire for the type of combustible material

37. Fire Extinguishers There are four types of fire extinguishers Type A: combustible solids Type B: combustible liquids Type C: electrical fires Type D: fires involving combustible metals Some fire extinguishers can be used on more than one type Using the wrong type of extinguisher can be dangerous

38. TYPE A FIRE

39. TYPE B FIRE

40. TYPE C FIRE

41. TYPE D FIRE

42. Location of Fire Extinguishers Fire extinguishers should be easily removed Should be easily lifted Location marked with red paint and signs Should be marked near the floor

43. LOCATION

44. Use Extinguishers cool the fire and remove oxygen Use foam, carbon dioxide, a pump tank, or dry chemicals CO2 extinguisher – direct the discharge as close to the fire as possible Dry chemical extinguisher – direct toward the base of the flames

45. Figure 2-34 Point the extinguisher at the material burning, not the flames

46. Equipment Maintenance Planned maintenance (PM) detects problems Hoses must be used for the gas or liquids for which they were designed Green hoses are used only for oxygen Red hoses are used only for fuel gases Never use oil grease, or other pipe-fitting compounds on joints Any leaking joints must be repaired

47. Work Area Should be picked up and swept clean Arc welding area painted with a flat dark color Portable screens used if welding outside the welding booth If a piece of hot material is left unattended, write hot on it before leaving

48. Hand Tools Used for assembly and disassembly of parts The adjustable wrench is the most popular tool Fewer points = stronger Mushroomed heads of chisels, punches, and the faces of hammers should be ground off Always use the correct tool for the job

49. Electrical Safety Injuries and death can be caused by electrical shock Resistance is lowered in the presence of water or moisture Electrically powered machines must be grounded Welding circuits must be turned off when the work station is left unattended

50. Electrical Safety Systems Two safe systems for electrical power tools: External grounding A wire runs from the housing to a third prong Third prong plug fits into grounded receptacle Double insulation Extra layer of insulation Eliminates need for grounded outlet