1

116 Trade Skills116 Trade Skills

SafetySafety

2

Pressure Vessels and PipingPressure Vessels and Piping

• The pressure in a vessel increases as the temperature of the vessel increases.– This pressure is a potential danger.

• Refrigerant cylinders should be stored in the upright position.

• Larger cylinders should be moved only when the protective cap is in place.

• Larger cylinders should be secured to carts designed for moving cylinders.

• Always wear gloves and eye protection.

• The pressure in a vessel increases as the temperature of the vessel increases.– This pressure is a potential danger.

• Refrigerant cylinders should be stored in the upright position.

• Larger cylinders should be moved only when the protective cap is in place.

• Larger cylinders should be secured to carts designed for moving cylinders.

• Always wear gloves and eye protection.

3

• Take all precautions to prevent tanks from falling over…

- the valve stem may break off, causing the tank to become a projectile

Pressure Vessels and PipingPressure Vessels and Piping

4

Electrical HazardsElectrical Hazards

• Exercise caution when working on or around electrical circuits.• Uncontrolled electric current flow can result in electrical shocks or burns.• Follow lock-out and tag procedures.• Exercise caution when working on live circuits.• Do not come in contact with energized conductors.

5

•Proper lockout and tagout procedures prevent electrical accidents!

•Prevents accidental or deliberate

activation of an electrical circuit.

•Is a requirement by OSHA when dealing with any electrical equipment.

•Any electrical circuit can not be activated until all padlocks are removed from the disconnect lock.

Lockout/Tagout (Electrical Safety)

6

NFPA 70E MANDATESELECTRICAL CIRCUIT LOCKOUT & TAGOUT

Your Lockout/Tagout will Consist of the following:

NFPA 70E MANDATESELECTRICAL CIRCUIT LOCKOUT & TAGOUT

Your Lockout/Tagout will Consist of the following:

1. Padlock2. Disconnect Lock (usually a 6

hole lock) 3. Padlock key ( Do not lose)

Lockout/Tagout (Electrical Safety)

7

NEC 250NEC 250

• NEC 250 ( National Electrical Code, Article 250):– Deals with proper electrical grounding.

• The most frequently cited Office of Safety and Health Administration(OSHA)electrical violation is improper occupational grounding of equipment or circuits.

• Equipment grounding must comply with the National Electric Code (NEC) Article 250.

• All noncurrent carrying metal enclosures for electrical equipment or wiring must be grounded.

• NEC 250 ( National Electrical Code, Article 250):– Deals with proper electrical grounding.

• The most frequently cited Office of Safety and Health Administration(OSHA)electrical violation is improper occupational grounding of equipment or circuits.

• Equipment grounding must comply with the National Electric Code (NEC) Article 250.

• All noncurrent carrying metal enclosures for electrical equipment or wiring must be grounded.

8

• Equipment grounding means a continuous copper conductor connected between the grounding electrode (rod/grid) connection, at the source transformer, and at each enclosure and equipment frame.

• Equipment grounding means a continuous copper conductor connected between the grounding electrode (rod/grid) connection, at the source transformer, and at each enclosure and equipment frame.

9

Electric ShockElectric Shock

• Shock occurs when you become a part of a circuit.

• Severity of a shock is determined by voltage, current, and the path the current takes as it flows through the body.

• Current flow through the heart can be fatal.• To help prevent shock, wear insulated boots

and do not stand in water while working on equipment.

• Shock occurs when you become a part of a circuit.

• Severity of a shock is determined by voltage, current, and the path the current takes as it flows through the body.

• Current flow through the heart can be fatal.• To help prevent shock, wear insulated boots

and do not stand in water while working on equipment.

10

Effects of Electric ShockEffects of Electric Shock

11

Ground ProtectionGround Protection

• Grounding wires provide protection from electric shock.

• The ground wire provides an alternative path for current to take.

• All tools should be properly grounded.• Do not use tools that have damaged or

missing ground prongs.

• Grounding wires provide protection from electric shock.

• The ground wire provides an alternative path for current to take.

• All tools should be properly grounded.• Do not use tools that have damaged or

missing ground prongs.

12

Line

Neutral

• Ungrounded tools have two prongs: One supplies line voltage to the tool and the other is neutral.

• If the tool becomes grounded, current can flow through the tool and through the user to ground causing shock.

Ground ProtectionGround Protection

13

LineNeutral

Ground

• Grounded tools have three prongs.

• If the tool becomes grounded, the current will flow to ground through the ground prong, protecting the user.

Ground ProtectionGround Protection

14

Other Grounding Tidbits…Other Grounding Tidbits…

• If wall outlets have only two connections and the tool has three prongs, use an adapter.

• Plastic-cased tools are double-insulated and often have only two prongs.

• Battery-operated tools are convenient and safer.

• Ground fault circuit interrupters (GFCI) sense small electrical leaks to ground.

• If wall outlets have only two connections and the tool has three prongs, use an adapter.

• Plastic-cased tools are double-insulated and often have only two prongs.

• Battery-operated tools are convenient and safer.

• Ground fault circuit interrupters (GFCI) sense small electrical leaks to ground.

15

Ground Fault Circuit InterruptersGround Fault Circuit Interrupters

• Ground-fault circuit interrupters (GFCI) are used to protect people from electrical shock.

• If an appliance is working properly, all electricity that the appliance uses will flow from hot to neutral. A GFCI monitors the amount of current flowing from hot to neutral.

• If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second.

• Ground-fault circuit interrupters (GFCI) are used to protect people from electrical shock.

• If an appliance is working properly, all electricity that the appliance uses will flow from hot to neutral. A GFCI monitors the amount of current flowing from hot to neutral.

• If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second.

16

Electrical BurnsElectrical Burns

• Avoid wearing metallic jewelry while working on electric circuits.– Metallic jewelry conducts electricity.

• Never use a screwdriver in an electrical panel when the power is on.

• Burns can result from electric sparks.

• Avoid wearing metallic jewelry while working on electric circuits.– Metallic jewelry conducts electricity.

• Never use a screwdriver in an electrical panel when the power is on.

• Burns can result from electric sparks.

17

GROUND

TERMINAL BLOCK

L1 L2

•If the screwdriver slips and makes contact between a hot terminal and ground…

- Electrical sparks can result, causing electrical shock or burn.

Electrical BurnsElectrical Burns

18

Ladder SafetyLadder Safety

• Non-conducting ladders should be used.• Fiberglass or wooden ladders are preferred.• Ladders should be placed on level surfaces.• Damaged ladders should not be used.• Ladders should be free of oil, grease, and

other slipping hazards.• Ladders should have slip-resistant feet.• Secure the ladder in place whenever

possible.

• Non-conducting ladders should be used.• Fiberglass or wooden ladders are preferred.• Ladders should be placed on level surfaces.• Damaged ladders should not be used.• Ladders should be free of oil, grease, and

other slipping hazards.• Ladders should have slip-resistant feet.• Secure the ladder in place whenever

possible.

19

Ladder TypesLadder Types

Type I-A ladders are heavy-duty and can handle up to 300 lbs.

Type I ladders can hold up to 250 lbs.

Type II ladders can hold 225 lbs. Type III ladders are for light duty

only and can hold up to 200 lbs.

Type I-A ladders are heavy-duty and can handle up to 300 lbs.

Type I ladders can hold up to 250 lbs.

Type II ladders can hold 225 lbs. Type III ladders are for light duty

only and can hold up to 200 lbs.

20

• A fiberglass A-frame ladder split halfway up the ridge of the leg rail, causing the worker on the ladder to fall to the floor.

• The employee injured his wrist.

• A fiberglass A-frame ladder split halfway up the ridge of the leg rail, causing the worker on the ladder to fall to the floor.

• The employee injured his wrist.

An Accident- What happened

21What Caused ItWhat Caused It

• An investigation showed the ladder appeared to be in good shape and not misused.

• It appeared to be a lighter shade than the other ladders on location, suggesting that it had been left out in the sun.

• When the ladder was standing alone, without weight on it, the split was extremely hard to see.

• An investigation showed the ladder appeared to be in good shape and not misused.

• It appeared to be a lighter shade than the other ladders on location, suggesting that it had been left out in the sun.

• When the ladder was standing alone, without weight on it, the split was extremely hard to see.

22

Ladder InspectionLadder Inspection

Rungs must be intact and free from grease or oil.

Make sure there are no splinters or sharp edges.

See that metal ladders are not dented or bent.

Rungs must be intact and free from grease or oil.

Make sure there are no splinters or sharp edges.

See that metal ladders are not dented or bent.

23Ladder InspectionLadder Inspection

Safety feet should be in place.

All support braces and bolts must be present and secure.

On extension ladders, make sure rope is not torn or frayed.

Safety feet should be in place.

All support braces and bolts must be present and secure.

On extension ladders, make sure rope is not torn or frayed.

24Ladder InspectionLadder Inspection

On stepladders, make sure the hinge spreader is working properly.

On stepladders, make sure the hinge spreader is working properly.

25Tag Defective LaddersTag Defective Ladders

• These ladders are properly tagged “Do Not Use”

• These ladders are properly tagged “Do Not Use”

26Read The Warning LabelsRead The Warning Labels

• They are there for a reason!

• They are there for a reason!

27Use of Step Ladders Use of Step Ladders

Always set level.

Always set level.

Be sure latches are down.

28

Don’t Lean a Step LadderDon’t Lean a Step Ladder

• The support leg (arrow) can contact the ground causing the step leg to kick out.

• Also employees should not work from the top or second step.

• The support leg (arrow) can contact the ground causing the step leg to kick out.

• Also employees should not work from the top or second step.

29

Proper Ladder ClimbingProper Ladder Climbing

• Use both hands to climb a ladder.

• Always face the ladder when climbing, descending or working.

• Avoid the top two steps of a stepladder and the top four rungs on other ladders.

• Use both hands to climb a ladder.

• Always face the ladder when climbing, descending or working.

• Avoid the top two steps of a stepladder and the top four rungs on other ladders.

30

Don’t Lean!Don’t Lean!

• Avoid excessive stretching or leaning.

• Workers should never work with one leg on a ladder and one off.

• A slip could result in serious fall.

• Avoid excessive stretching or leaning.

• Workers should never work with one leg on a ladder and one off.

• A slip could result in serious fall.

NO!

31

Safe Step Ladder UseSafe Step Ladder Use

• Always face the ladder

• Stay off top two steps.

• Always face the ladder

• Stay off top two steps.

32

Unsafe Step Ladder UseUnsafe Step Ladder Use

• Do not straddle the top unless the ladder is designed for it.

• Do not straddle the top unless the ladder is designed for it.

NO!

33

Use of Extension LaddersUse of Extension Ladders

34

Set Feet ProperlySet Feet Properly

Firm BaseSet both feet level

and on the pads

Firm BaseSet both feet level

and on the pads

Soft BaseSet on the spikes and seat the ladder in the ground.

35

Not a Firm FoundationNot a Firm Foundation

36

Set The Proper AngleSet The Proper Angle

The distance from the bottom of the ladder to the wall should be one-fourth of the ladder's working height.

An extended arm will be close.

The distance from the bottom of the ladder to the wall should be one-fourth of the ladder's working height.

An extended arm will be close.

4

1

37

Check The LocksCheck The Locks

• Always check to be sure the extension locks are properly seated.

• Always check to be sure the extension locks are properly seated.

38

This Is A Poor Set UpThis Is A Poor Set Up

• The top could fall out with any slip at the base.

• The angle is too steep.

• The top could fall out with any slip at the base.

• The angle is too steep.

39

Working From a LadderWorking From a Ladder

• Always face the ladder.

• Keep one hand on the ladder for hold.

• Do not work on top four steps.

• Work within easy reach.

• Always face the ladder.

• Keep one hand on the ladder for hold.

• Do not work on top four steps.

• Work within easy reach.

40

Ladders Near Electrical Ladders Near Electrical

• Use non-conductive ladders.

• Don’t carry or move extension ladders while extended.

• Get help moving ladders to maintain control.

• Use non-conductive ladders.

• Don’t carry or move extension ladders while extended.

• Get help moving ladders to maintain control.

41

Slips, Trips & FallsSlips, Trips & Falls

• The #1 cause of office employee injuries! – 265,000 nonfatal injuries from slips, trips, and

falls annually result in one or more days away from work per incident

– Slips, trips, and falls result in 17% of all nonfatal workplace injuries per year, the highest injury rate of any regulated activity

• The #1 cause of office employee injuries! – 265,000 nonfatal injuries from slips, trips, and

falls annually result in one or more days away from work per incident

– Slips, trips, and falls result in 17% of all nonfatal workplace injuries per year, the highest injury rate of any regulated activity

42

Heat-related Safety IssuesHeat-related Safety Issues

• Torches concentrate large amounts of heat.• Keep torches away from combustible

materials.• Always keep a fire extinguisher nearby.• Use a fire shield when soldering near

combustibles.• Never solder tubing on a sealed system.• Hot pipes and motors can cause burns.• Working outdoors or in hot attics can cause

injury.

• Torches concentrate large amounts of heat.• Keep torches away from combustible

materials.• Always keep a fire extinguisher nearby.• Use a fire shield when soldering near

combustibles.• Never solder tubing on a sealed system.• Hot pipes and motors can cause burns.• Working outdoors or in hot attics can cause

injury.

43

Cold-related Safety IssuesCold-related Safety Issues

• Cold can be as dangerous as heat.• Liquid refrigerant can cause frostbite.• R-22 boils at -41°F at atmospheric pressure.• Wear warm clothing and waterproof boots

when working in cold, wet environments.• Cold-weather gear should be worn when

working in low-temperature freezers.

• Cold can be as dangerous as heat.• Liquid refrigerant can cause frostbite.• R-22 boils at -41°F at atmospheric pressure.• Wear warm clothing and waterproof boots

when working in cold, wet environments.• Cold-weather gear should be worn when

working in low-temperature freezers.

44

• Never try to stop rotating machinery by hand!

Mechanical Equipment SafetyMechanical Equipment Safety

45

Moving Heavy ObjectsMoving Heavy Objects

• Use the safest method to move heavy objects.

• Get help from others when the object is heavy.

• Lift with your legs, not your back.– Use hand trucks whenever possible– Pry bars and dollies can be used.– Use a back brace– Pry bars can also be used

• Use the safest method to move heavy objects.

• Get help from others when the object is heavy.

• Lift with your legs, not your back.– Use hand trucks whenever possible– Pry bars and dollies can be used.– Use a back brace– Pry bars can also be used

46

Refrigerants in the Breathing SpaceRefrigerants in the Breathing Space

• Refrigerant gases are heavier than air.• These gases displace oxygen.• Avoid breathing refrigerant vapors.• Use proper ventilation.• Special leak detectors and alarms are

required in certain applications.• ASHRAE Standard 34-1992 addresses

refrigerant toxicity and flammability.

• Refrigerant gases are heavier than air.• These gases displace oxygen.• Avoid breathing refrigerant vapors.• Use proper ventilation.• Special leak detectors and alarms are

required in certain applications.• ASHRAE Standard 34-1992 addresses

refrigerant toxicity and flammability.

47

Chemical SafetyChemical Safety

• Used to clean condensers, evaporators, and other pieces of equipment

• Used for water treatment• Should be handled according to

manufacturer’s directions– Follow manufacturer’s first aid procedures.

• Can cause irritation to the eyes, throat, and skin.– Be very careful!

• Used to clean condensers, evaporators, and other pieces of equipment

• Used for water treatment• Should be handled according to

manufacturer’s directions– Follow manufacturer’s first aid procedures.

• Can cause irritation to the eyes, throat, and skin.– Be very careful!

48

Fire ClassificationsFire ClassificationsFire ClassificationsFire Classifications

• Fires can be divided into four classes:o Class A: wood and papero Class B: grease, liquids, and gaseso Class C: energized electric

equipmento Class D: metals

• Fires can be divided into four classes:o Class A: wood and papero Class B: grease, liquids, and gaseso Class C: energized electric

equipmento Class D: metals

49

Class A Fire ExtinguishersClass A Fire Extinguishers

•Class A Extinguishers are for ordinary combustible materials such as paper, wood, cardboard, and most plastics. The numerical rating on these types of extinguishers indicates the amount of water it holds and the amount of fire it can extinguish.

•Geometric symbol (green triangle)

50

Class B Fire ExtinguishersClass B Fire Extinguishers

• Class B fires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil. The numerical rating for class B extinguishers indicates the approximate number of square feet of fire it can extinguish.

• Geometric symbol (red square)

• Class B fires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil. The numerical rating for class B extinguishers indicates the approximate number of square feet of fire it can extinguish.

• Geometric symbol (red square)

51

Class C Fire ExtinguishersClass C Fire Extinguishers

• Class C fires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish class C fires - the risk of electrical shock is far too great! Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive.

• Geometric symbol (blue circle)

• Class C fires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish class C fires - the risk of electrical shock is far too great! Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive.

• Geometric symbol (blue circle)

52

Class D Fire ExtinguishersClass D Fire Extinguishers

• Class D fire extinguishers are commonly found in a chemical laboratory.

• They are for fires that involve combustible metals, such as:– magnesium, – titanium, – potassium – and sodium. – These types of extinguishers

also have no numerical rating, nor are they given a multi-purpose rating - they are designed for class D fires only.

• Geometric symbol (Yellow Decagon)

• Class D fire extinguishers are commonly found in a chemical laboratory.

• They are for fires that involve combustible metals, such as:– magnesium, – titanium, – potassium – and sodium. – These types of extinguishers

also have no numerical rating, nor are they given a multi-purpose rating - they are designed for class D fires only.

• Geometric symbol (Yellow Decagon)