Practice Questions For Nebosh Examinations – Hazards

Front 1

Excessive dust levels have been discovered in a workplace, the principal cause being the inefficient local exhaust ventilation system (LEV).

(i) Identify FOUR indications that could have highlighted the LEV systems’ inefficiency. (4)

Back 1

• Deposits of dust on surfaces and people
• Visible particles in the air
• Discomfort and irritation by employees
• Air monitoring reviews
• Actual ill-health in employees due to exposure to dusts

Front 2

Excessive dust levels have been discovered in a workplace, the principal cause being the inefficient local exhaust ventilation system (LEV).

(ii) Outline the factors which could have reduced the LEV systems effectiveness (8)

Back 2

• Poor design
• Lack of planned testing
• Lack of maintenance
• Extraction hood too far from dust source
• Damaged or blocked ducting or filters
• System alterations – unauthorized
• Settings incorrect
• Faulty fan
• Process changes that could lead to greater dust emissions.

Front 3

Excessive dust levels have been discovered in a workplace, the principal cause being the inefficient local exhaust ventilation system (LEV).

(iii) Describe other methods of control to minimise levels of airborne dust except from LEV. (8)

Back 3

• Hierarchy of control
• Eliminating the process causing the dust
• A change in process to reduce dust amounts
• Substitution of materials i.e. capsule form, pellets or liquid
• Segregation or enclosure of the dust creation process
• Damping down the dust for easier removal such as vacuuming
• Methods of cleaning so as not to disturb the dust i.e. vacuuming instead of sweeping

Front 4

Outline necessary precautions to be taken when pedestrians are required to work close to vehicle movement areas. (8)

Back 4

• Segregation systems for vehicles and pedestrians
• Clear and appropriate road markings
• Visibility – mirrors, transparent doors, adequate lighting etc.
• Vehicular audible warnings
• Site rules
• High-visibility clothing
• Good housekeeping
• Training and supervision of all involved on site

Front 5

Factory cleaning staff uses a rotary floor polisher each night.

(i) Identify the associated hazards. (4)

Back 5

• Segregation systems for vehicles and pedestrians
• Clear and appropriate road markings
• Visibility – mirrors, transparent doors, adequate lighting etc.
• Vehicular audible warnings
• Site rules
• High-visibility clothing
• Good housekeeping
• Training and supervision of all involved on site

Front 6

Factory cleaning staff uses a rotary floor polisher each night.

(ii) Outline what control measures could be used to reduce the risks. (4)

Back 6

• Guarding
• Cable management
• Isolation for the task of changing brushes
• Appropriate non-slip footwear
• Regular testing and maintenance
• Residual current devices – RCD’s
• Training to ensure pre-use checks

Front 7

Outline precautions needed when maintenance work is being carried out in an underground storage vessel. (8)

Back 7

• Permit-to-work
• Risk assessment
• Isolation
• Pre-cleaning
• Purging and testing the vessel’s atmosphere
• Safe means of access and egress
• Appropriate tools i.e. non-spark
• P.P.E
• Appropriate lighting
• Continual monitoring
• Competent and trained personnel
• Good communication systems between tank and above-ground workers
• Maintenance of detailed emergency procedures

Front 8

Outline the principal requirements to ensure excavation work is carried out safely. (8)

Back 8

• Examine the support structures weekly by competent person
• Record examination
• Inspect working part daily or per shift if deeper than 2m
• Inspect support material before use
• Support work done under supervision of competent person
• No person to work in excavation unless competently examined
• No projecting nails on support structure
• No materials left near edges of excavation

Front 9

With respect to work-related upper limb disorders (WRULD’s).

(i) Identify typical symptoms. (4)

Back 9

• Back, neck and shoulder pain
• Swollen joints
• Reduced mobility and stiffness
• Cramps and muscle fatigue/tiredness

Front 10

With respect to work-related upper limb disorders (WRULD’s).

(ii) Outline the factors that would increase the development of WRULD’s. (4)

Back 10

• Display screen equipment issues – DSE
• Layout of workstation
• Insufficient breaks from the task
• Inadequate space leading to poor postures
• Excessive force needed to carry out tasks
• Frequency of the task
• Vibrating tools/equipment
• Pre-existing medical conditions
• Pregnant women

Front 11

Outline what is required for a safe means of escape when evacuating a building in the event of fire. (8)

Back 11

• At least two escape routes in opposite directions, none to exceed the recognised travel distance
• Escape route fire integrity
• Self closing fire doors that open outwards easily
• Escape routes clearly marked
• Emergency lighting for routes
• Routes kept free from obstruction
• Safe, clearly signed assembly point

Front 12

(i) What are the principal hazards associated with the use of ladders at work? (3)

Back 12

• Poor maintenance
• Incorrect use
• Incorrect locations

Front 13

(ii) Explain how these hazards may be eliminated or reduced. (5)

Back 13

• Inspection and repair
• Correct storage
• 75 degrees slope (1 in 4)
• Secured top and base
• Not to use aluminium ladders near overhead cables

Front 14

Outline the precautions to protect against electrocution when:

(i) Excavating near underground cables (4)

Back 14

• Supply isolation
• Cable routes identification via plans and cable detectors
• Checking for service box covers
• Marking of cable routes
• Digging with hand-tools

Front 15

Outline the precautions to protect against electrocution when:

(ii) Working near overhead power lines (4)

Back 15

• Isolation
• Goal-post barriers defining clearance distances
• Use of signs and bunting to clearly mark danger zones
• Safe access routes under lines
• Use of marshals and banksmen when cranes, excavators or tipper lorries may approach
• Restriction on use of metal ladders and scaffold tubes

Front 16

List EIGHT routine inspection items included on a checklist at the beginning of a shift, before using a fork-lift truck. (8)

Back 16

• Tyre pressure and condition
• Lights functioning (where fitted)
• Secure and properly adjusted seats
• Undamaged mirrors with good vision
• Leakages from various fluids – diesel, battery acid, oil, brake fluid etc.
• Battery connections
• Chains in good order
• Horn operates
• Reversing audible signals where fitted
• Forks in good order
• Break checks, including hand break
• Forks do not drop when raised – hydraulic fluid levels ok
• No play in steering wheel

Front 17

Outline EIGHT precautions that should be considered to prevent injuries to children who may be tempted to access a construction site. (8)

Back 17

• Fencing
• Warning signs of any dangers
• Security patrols
• CCTV
• Isolating services
• Reducing heights of materials
• Covering excavations
• Removing ladders – lashing the ladders – to deny access to scaffolding
• Securing tools, chemicals, equipment and vehicles under lock and key
• Community liaisons

Front 18

i. Define ‘ergonomics’. (2)

Back 18

• The study of the interaction between workers and their work, and is concerned with the design of the workplace, work equipment and work methods with the needs and limitations of the human operator in mind.

Front 19

ii. Outline which health issues could be caused by poor ergonomic designs of display screen equipment (DSE) workstations. (4)

Back 19

• Work-related upper limb disorders such as: pain in shoulders, arms (including forearms), wrists, hands, fingers and even neck pains.
• Eye strain
• This question asks for an outline which would typically include detail of the symptoms and the circumstances that would make the effects more likely.

Front 20

iii. Outline which factors should be considered for an ergonomic assessment of a DSE workstation. (14)

Back 20

• Equipment
• Environment
• Task
• Individual - inter-relationships between these four
• Repetition
• Working posture of fingers, hands and wrists
• Working posture of shoulders and arms
• Psychosocial factors such as: pace of work, unplanned overtime/shift work, little control over own work, stressful deadlines, lack of training

Front 21

Use sketches to clearly show what is meant by the following terms relating to mechanical hazards from moving parts of machinery.

i. Entanglement (2)

Back 21

Please suggest your Answer. Thank You. Paul

Front 22

Use sketches to clearly show what is meant by the following terms relating to mechanical hazards from moving parts of machinery.

ii. Crushing (2)

Back 22

Please suggest your Answer. Thank You. Paul

Front 23

Use sketches to clearly show what is meant by the following terms relating to mechanical hazards from moving parts of machinery.

iii. Drawing-in (2)

Back 23

Please suggest your Answer. Thank You. Paul

Front 24

Use sketches to clearly show what is meant by the following terms relating to mechanical hazards from moving parts of machinery.

iv. Shear (2)

Back 24

Please suggest your Answer. Thank You. Paul

Front 25

i. Outline the main considerations when deciding on the siting of fire extinguishers. (4)

Back 25

• Accessibility
• Visibility
• Proximity to exits and escape routes
• Travel distances
• Support of the equipment off the ground
• Free from obstruction
• Protection from the weather
• Protection from other sources of damage

Front 26

ii. Outline maintenance and inspection requirements for fire extinguishers. (4)

Back 26

• Inspection – routine i.e. monthly visual checks ensuring extinguishers are in place, have not been discharged and have no obvious damage.
• Maintenance – annual tests by a competent person according to the manufacturer’s instructions in order to ensure the extinguishers integrity, with faulty equipment being removed and replaced.

Front 27

Explain these terms with regards to noise control.

i. Silencing 2)

Back 27

• The suppression of noise generated by the air flow, gas or steam in ducts and pipes, or when exhausted to the atmosphere, and uses either absorptive material or baffles

Front 28

Explain these terms with regards to noise control.

ii. Absorption (2)

Back 28

• Reduction of reflected noise by using materials such as foam or mineral wool

Front 29

Explain these terms with regards to noise control.

iii. Damping (2)

Back 29

• Reduction of amount of noise radiating from large panels and is effected by increasing the stiffness of the panels

Front 30

Explain these terms with regards to noise control.

iv. Isolation (2)

Back 30

• Physical separation of people from the noise source such as acoustic booths or havens, or by isolating the noise by vibration using flexible pipes or anti-vibration machine mounts

Front 31

Outline a procedure for the safe lifting of a load whilst using a crane, ensuring the crane has been properly selected and positioned for the task. (8)

Back 31

• The suitability of the lifting tackle such as its safe working load, free from defects, etc.
• The competence of the people involved i.e. driver, slinger, signaler
• The load must be lifted vertically, secure balanced and controlled during the lift by the use of tag lines whenever necessary
• Proper communication
• Area must be kept clear of non-essential personnel
• Lifting, moving and lowering must be performed at the correct rate maintaining proper control at each part of the operation

Front 32

i. Define the occupational health term “target organ”. (2)

Back 32

• A part of the body that sustains an adverse effect when exposed to, or is contaminated by, a particular substance or agent.
The harmful effects of a toxic substance confined to particular organs such as the lungs, liver, skin or kidneys.

Front 33

ii. Outline personal hygiene methods that would decrease the risk of ingesting a hazardous substance. (6)

Back 33

• Regular hand washing
• Restriction of smoking and eating in the workplace
• P.P.E such as gloves
• Removal and cleaning of contaminated clothing

Front 34

Identify FOUR different types of hazards that could require the use of special footwear explaining in EACH type how the footwear protects the wearer. (8)

Back 34

• Falling objects – steel toe-caps
• Sharp objects – steel in-soles
• Flammable atmospheres – anti-static footwear
• Spread of contamination – washable boots
• Molten metal – heat resistant boots and gaiters
• Electricity – rubber soles
• Wet environments – impermeable Wellington boots
• Slippery surfaces – non-slip soles
• Cold environments – thermally insulated footwear

Front 35

List the items to include on an inspection checklist for portable electrical appliances. (8)

Back 35

• Appropriate equipment for the task and environment
• Equipment is tested
• Equipment, plugs, connectors and cables are free from damage
• Correct wiring and sound connections
• Fuses and other means of preventing excess current in place and correct rating
• Accessible and appropriate means of isolation
• System not overloaded

Front 36

Outline the main precautions to be taken whilst undertaking an excavation project. (8)

Back 36

• Detection of services using plans, cable/pipe detectors etc.
• Supporting the sides
• Storage of materials and spoil away from the edge
• Measures to prevent vehicles falling into excavations such as stop blocks
• Guard rails and barriers
• Measures to prevent collapse of adjacent structures
• Safe means of access/egress
• Testing for, and ventilation of, noxious fumes
• Measures to pump out water
• Safe procedures for working with mechanical plant
• Inspection, training and supervision

Front 37

i. State TWO asbestos related respiratory diseases. (2)

Back 37

• Mesothelioma
• Asbestosis
• Lung cancer

Front 38

ii. Identify where you are likely to encounter asbestos in a building undergoing renovation work. (6)

Back 38

• Pipe lagging
• Wall and roof panels
• Ceiling tiles
• Textured coatings such as fire resistant encapsulation of metal girders
• Insulation materials
• Gaskets and other seals

Front 39

List ways that may cause a fork-lift truck to become unstable when in use. (8)

Back 39

• Insecure, excessive or uneven loading
• Incorrect tilt and/or elevation of forks whilst traveling
• Uneven or unconsolidated ground
• Slopes and incorrect procedures to deal with them
• Obstructions overhead and low level