B1 B2 B3 Flashcards
What is the required height range for guardrails above the work surface?
40 to 44 inches
This height range helps ensure maximum safety for workers near edges.
What are the components of a guardrail system?
Top rail, mid rail, and toe board
These components work together to provide effective fall protection.
What is the minimum horizontal load that guardrails must resist?
125 lb.
This requirement helps ensure the structural integrity of the guardrail under stress.
What is the maximum spacing allowed for uprights in a guardrail system?
8 to 10 feet
Proper spacing is crucial for maintaining the strength and stability of the guardrail.
What size should the top rail be for uprights spaced at 8 feet on center?
Minimum of a 2 x 4
This dimension provides adequate support for the guardrail.
What size should the top rail be for uprights spaced up to 10 feet on center?
Minimum of a 2 x 6
A larger dimension is necessary to maintain stability at greater distances.
What are the acceptable sizes for midrails in a guardrail system?
1 x 6 or 2 x 4
Midrails help to prevent falls through the guardrail system.
What must be done to a safety harness after a fall arrest accident?
It must be inspected and re-approved by the manufacturer before reuse for fall arrest protection.
Why is it important to adjust a safety harness?
A poorly fitting harness is uncomfortable and may not protect you.
What is the function of a lanyard in fall protection?
The lanyard connects the harness to the lifeline.
How should the rope grab be positioned on the lifeline?
To allow a maximum free fall of 120 cm (4 ft) unless equipped with a shock absorber.
What standards must safety lanyards meet?
They must meet CSA standards and bear the CSA label.
When should wire rope lanyards be used?
When using cutting tools or in areas where abrasion could damage the lanyard.
What should be used if there is a risk of electrical shock while using cutting tools?
Two non-conductive lanyards.
What is the purpose of a rope grab?
To connect the lanyard to a vertical lifeline and adjust the free fall distance.
What is the maximum free fall distance that a rope grab should maintain?
No more than 120 cm (4 ft).
What happens to the rope grab when the worker moves up or down?
It moves up or down the same distance on the lifeline.
What is prohibited by the WorkSafeBC OHS regulation regarding rope grabs?
The use of a triple sliding hitch to connect a rope lanyard to a lifeline.
What is the primary function of shock-absorbing devices?
Reduce the impact of a lifeline stopping a fall
When is a shock-absorbing device required?
If a wire rope lanyard is used
What is the free-fall limit when using a shock-absorbing device?
Increased to 2 m
What is the purpose of a snap hook in a personal fall arrest system?
Connects the lanyard to the rope grab and to the harness
What is a crucial requirement for the snap hook?
Must be self-locking
List the requirements for vertical lifelines used in a personal fall arrest system
- Be CSA approved
- Have a breaking strength of at least 6000 lb. (26.7 kN)
- Be made from synthetic fibre or wire rope
- Be free of knots and splices, except at termination points
- Be secured to an anchor capable of supporting at least 5000 lb. (22 kN)
- Have only one worker attached to it
- Extend to within 1.2 m (4 ft.) of the ground or a safe lower landing
- Not exceed a suspended length of 91 m (300 ft.) without prior approval from WorkSafeBC
What is the minimum breaking strength required for vertical lifelines?
At least 6000 lb. (26.7 kN)
What is the maximum suspended length for vertical lifelines without prior approval?
91 m (300 ft.)
What is the requirement for horizontal lifelines in terms of support per worker?
Must provide 800 lb. of support for each worker attached to the line
What is the minimum breaking strength required for horizontal lifelines?
At least 20,000 lb. (89 kN)
What diameter must horizontal lifelines be made from?
½” diameter wire rope
What is the maximum span allowed for horizontal lifelines?
Less than 18 m (60 ft.)
What is the unloaded sag requirement for horizontal lifelines?
1/60th of the span
What is the minimum height requirement for horizontal lifelines above the working surface?
At least 1 m
What is the maximum free fall allowed for horizontal lifelines?
120 cm (4 ft.)
How many workers can be attached to a horizontal lifeline?
Maximum of three workers
What is the minimum clear space required below the working surface for horizontal lifelines?
3.6 m (12’)
True or False: Vertical lifelines can have multiple workers attached to them.
False
Voltage classifications
0-30 is extra low voltage
31-750 is low voltage
750 volts + is high voltage
How does temperature affect skin resistance?
Resistance is further reduced if temperatures are high due to salt and moisture in perspiration
Hard work or vigorous exercise may also change skin resistance due to perspiration. Conversely, cold dry weather may increase skin resistance.
What happens to body resistance when there are breaks in the skin?
Breaks in the skin drastically reduce body resistance to well below 100 ohms
This is because the insulating layer is absent.
How does applied voltage affect skin resistance measurements?
Skin resistance changes with applied voltage
Testing with an ohmmeter at 1.5 volts gives a high reading, while testing with a 500 volt megger gives a result only one-tenth as big.
Is it safe to use a megger to test body resistance?
No, do not use a megger to test body resistance because a shock will result.
What happens to skin resistance during current flow?
Skin resistance decreases with time during current flow.
What is the body resistance measured between the ears?
Between the ears, body resistance is only 100 ohms.
What is the body resistance measured from hand to foot?
Resistance measured hand to foot is closer to 500 ohms.
What is the most important factor in determining the deadliness of an electric shock?
The amount of current forced through the body.
What current levels can produce painful to severe shock?
Currents over 10 mA (0.01 amp) can produce painful to severe shock.
What current level can be lethal?
Any current over 50 mA (0.05 amp) can be lethal.
Do victims of high-voltage shock respond better to resuscitation than low-voltage shock victims?
Yes, victims of high-voltage shock usually respond to resuscitation more readily.
What is a common misconception regarding the danger of different voltage levels?
75 volts is as life-threatening as 1000 volts.
What effect does a current of 1 mA or less have on the body?
No sensation. Shock probably not felt.
What effect does a current between 1 and 8 mA have?
Shock is felt, but is not painful. Victim can let go at will.
What happens with a current between 8 to 15 mA?
Shock is painful. Victim can let go at will. Muscular control is kept.
What happens with a current between 15 to 20 mA?
Shock is painful. Victim cannot let go. Muscular control is lost. Breathing is difficult.
What’s the act that gives work safe bc authority?
Workers compensation act
What four parts is the workers compensation app comprised of?
1 compensation to workers and dependants
2 liability of employers not within the scope of part 1
3 occupational health and safety
4 Appeals
Minimum approach distance for working close to to exposed electrical conductors or equipment. Over 750V to 75kV
3m or 10 feet
2m passing under
Minimum approach distance for working close to to exposed electrical conductors or equipment. Over 75kV to 250kV
4.5m or 15 feet
3m passing under
Minimum approach distance for working close to to exposed electrical conductors or equipment. Over 250 kV to 550 kV
6m or 20 feet
4m passing under
OHS Parts 1-4
The Core requirements apply to all work places.
OHS Parts 5-19
General hazards found in a number of work places.
OHS Part 20-32
Requirements that apply to specific industries or specific hazardous activities.
