Interview Questions and answers (SAFETY FIRST)

1. What is Fire?
Ans: Fire is a chemical chain reaction, were required three elements
(1) Heat
(2) Oxygen
(3) Fuel.

2. How many types of fire classifications are there and what are those?
Ans: There are five types, A.B.C.D.K

Class A: Ordinary combustible
Ex: Paper, Wood, Garbage, Plastics.
Class B: Fire involves inflammable liquid
Ex: Petrol, Diesel.
Class C: Involves in Electricity
Ex: Switch panel, Boards.
Class D: Metal fire
Ex: Magnesium, Potassium, Aluminum.
Class K: Kitchen fire.
Ex: Cooking oil, Animal fat,Vegetable fat.

3. What are the colour codes of fire extinguisher?
Ans: A-red


4. What will you do in case of emergency situation?
Ans: 1. Inform the surrounding people by raising alarm.

  1. If it is small fire I try to extinguish the fire with extinguisher.
  2. Inform the fire department and exit to the assembly point in case of Big fire.

5. How will you evacuate the area in case of emergency arise?
Ans: 1. Sound the alarm by triggering (breaking the glass) the fire alarm actuator.

  1. Evacuate the building by proceeding toward the emergency exit door.
  2. If you have to pass through the smoke, keep low and follow the corridor towards the emergency exit.
  3. Proceed to the Assembly Point and wait for further instruction from the Evacuation warden.

6. Types of PPE and their purpose?
Ans: 1. Head Protection: - hardhats

  1. Ear protection: - Earmufs, Ear plugs.
  2. Nose: - Respirators supplying air, Respirators Cartiage type.
  3. Eye protection: - Googles, Safety glasses.
  4. Face: - Face shield.
  5. Body: - Coverall, overall, full body suits.
  6. Hand glows: - Neproni Butyl, Lactive Corrosive liquids.
  7. Shoes: - Steel tow, Slip resists shoe, Non-Conductive shoe.

7. What is fire alarm system or fire control panel system how many types are there?
Ans: Fire alarm is a automatic electronic panel which will indicate when the fire occur. Fire alarm is connected to smoke detector and heat detector. When smoke comes down the detector will give the signal to alarm panel and the alarm gives the indication water is 9.12 meters. Or fire alarm control unit (FACU), is the controlling component of a fire alarm system. The panel receives information from environmental sensors (Heat detectors or smoke detectors) designed to detect changes associated with fire.
There are four basic types of panels: coded panels, Conventional panels, Addressable Panels, and Multiples systems.

8. What is smoke and heat detector and how does it work?
Ans: Smoke: It detects the smoke if there is a fire on work side or building.
Heat Detector: It detects the temperature in case of fire.

9. What is Risk Assessment?
Ans: It is a systematic way to identify the hazards and to control those hazards for a specific task.

10. What is work permit system and how many types are there?
Ans: It is a formed documented control process which takes accounts of all the foreseeable interactions between the workers, the environment and the associated hazards. There are seven types of work permit they are:-

  1. Hot work permit
  2. Cold work permit
  3. Electrical work permit
  4. Working at height work permit
  5. Excavation work permit.
  6. Acid area work permit
  7. Vessel entry work permit.

11. Definition of Hazard, Accident and Near Miss?
Ans: Hazard: - Anything which has a potential to cause harm, or damage to the property.
Accident: Unplanned unwanted events which results harm or damage to property.
Near Miss: In an incident in which no injury or damage.

12. How many types of safety reports are there?
Ans: Weekly, Monthly, Annual.

13. What is tool box talk or safety induction?
Ans: Tool box Talk: - General training provided to the worker before they start the work.
Safety Induction: These training provided to the new employees about general safety rules, emergency response procedure hazard the accident reporting.

14. Definition of Safety?
Ans: Free from accident or hazards.

15. How to use fire extinguisher?
Ans: Pass
P - Pull the pin.
A - Aim the hose at base of fire.
S - Squeeze the handle.
S - Sweep the hose.

16. What kind of safety precaution do you take to protect people, property and environment at work site?
Ans: 1. Provide training to the people
2. Conducting inspection
3. Safety meetings
4. Preparing risk assignment.
5. Monitoring.
6. Regular audit.

17. What is fire sprinkler system and how does it work?
Ans: Sprinkler system is installed inside the building. It is working under the water pressure. On the end of pipe lines sprinkler head is fitted the sprinkler head is rated to 68 degree. In case of fire the temperatures will be increase and the sprinkler head will broke and get sufficient water with pressure.
Distance between the sprinkler head is 3 meters. The coverage area of the sprinkler water is 9.12 meters.

18. How many types of hazards are there and what are those?
Ans: There are five types of hazards.

  1. Physical hazards: - caused by physical energy noise vibration.
  2. Chemical hazards: - through chemical.
  3. Biological hazards: - through microorganism, bacteria, virus fungi.
  4. Ergonomic hazards: - Caused by manual building.
  5. Cytological hazards: - Caused by work stress pressure.

19. How to inspect the fire extinguisher?
Ans: 1. we need to check not obstructed.
2. Check pressure.
3. Check for safety pin should to intext.
4. No physical cracks.

20. What you will do if you find any unsafe condition on work site?
Ans: Unsafe condition should be reported and fixed.


• Don’t Panic & Stop Work
• Proceed to the nearest emergency exit & Don’t run, walk fast
• Use the staircase, never use the elevator
• Walk along the LEFT side of the staircase, Leave the right side for Life Savers and rescue team
• Give First preference to the physically challenged, pregnant mothers and the elderly
• Proceed to the safe assembly point & Do not re-enter the building until the signal is given
• Max. time for evacuation – 2.5 to 3.0 minutes


  • FACP: Fire Alarm Control Panel
  • BMS: Building Management System
  • HSE: Health Safety & Executive
  • HIRARC: Hazard Identification, Risk Assessment, Risk Control
  • BS: British Standard
  • HSW: Health Safety Work
  • CPR: Cardio Pulmonary Resuscitation
  • EMS: Emergency Medical Service
  • ERT: Emergency Response Team


v HELMET Z-89.1 (ANSI) 1981
v SAFETY GLASS Z-87+ (ANSI) 1968
v SAFETY SHOES Z-47.1 (ANSI) 1967
v RESPIRATOR Z-88.2 (ANSI) 1992

Safety is the control of hazards to obtain any acceptable level of risk, to perform a job properly and avoid incident and accidents at worksite…!!!


It is the documents submitted by contractor to client, covering the general work procedure of a particular job in safe manners as per required standard.


We can plan and execute the work easily and safely, it also helps to know the codes and standards used for each activity.


Job safety analysis is the step by step analysis of a job to determine the safe working procedures
It includes the following steps.
a.) Watch the job being done
b.) Break the job down into steps
c.) Described the hazards in each step of task
d.) Identity the desired controls measures and
e.) Implement these counter measures in the job executions.


is a written document authorizing a person or a group to perform maintenance, inspections or construction work.


Hot work permit,
Cold work permit,
Confined space entry permit,
Excavation permit,
Lifting permit,
Night work permit,
Radiography permit,
Other permits as per job requirement.

6). What is Safety?

Safety is a state where the Risk has been Eliminated or Reduced to an Acceptable Level.
Control of Accidental Loss of Resources Human and Material

7). What is near-miss?

An undesirable event which has the potential to cause loss


Any space having a limited means of access and egress, when subject to the hazards like deficiency of Oxygen, toxic or flammable gases or substances, dust etc.


The Oxygen level in Confined space is 19.5% to 23.5%.


If properly ventilated, gas test reading are satisfactory, properly barricaded and warning signs are Posted, trained stand by man is present with log sheet, sufficient lightening and low voltage Electricity (24V-110V), proper means of communication, locked and tagged out if necessary, lifeline man retrieval System if necessary etc.


He is one who is aware of the confined space hazards and knows how to react if any thing goes wrong, able to maintain confined space entry log sheet etc.


Oxygen Deficiency or Enrichment, presence of toxic or flammable gases, chemical hazards fire hazards.
Fall of materials fall hazards electrocution dust sounds heat or cold caught in between moving.
Equipments engulfment etc.


He is responsible for the safety of entrants, should be present whenever people are working in confined space, maintain update entry log sheet, maintain continuous communication with entrants and monitor conditions in the confined space to ensure a safe working atmosphere, prevent unauthorized personnel, initiate alarm for help if in need evacuate the entrants if conditions are not satisfying or in case of any general evacuation initiated contact rescue personnel if necessary etc.


Pipes, Vessels, Tanks, boilers, and Tube areas Silos Trenches and excavation deeper then 4feet sludge Pits Duct works etc.


Welding Grinding Chemical Use of gas cutting sets erection of materials


Is one who is properly trained and authorized to perform a specific work in a safe manner competent person one who is capable of identifying existing predictable hazards and who has authority to make prompt corrective actions.


Accident is uncontrolled events that results in undesirable consequences to personnel injury, illness of the assets damage or loss or to the environment.
An Undesirable event which causes harm to personal Damage to property.


A Potential hazards, which has not yet caused an accident or an occurrence that did not results in but have the potentials to results in undesirable consequences to personnel illness injury and or to the assets damage loss or to the neighboring community and environment.
An Undesirable event which has the potential to cause loss.


Concerned area supervisor or site safety representatives.


A team of frontline supervisor, HSE manager sub contractor representatives if subcontractor personnel
Are injured high officials depending upon the severity of accident.


To find out the root cause of accident makes recommendations to prevent re-occurrence and evaluate the effectiveness of emergency response.


Waste management means safely disposing the by-product of a process or a work to the environment after the proper treatment if necessary so that no threat for living properties and environment exists.


Materials safety data sheets is the documents prepared by the manufacturer giving product name producer address emergency contact phone number information of ingredients possible hazards first aid measures precaution to be taken for storage and handling recommended PPE extinguisher physical and chemical properties etc.


Isotope means one or more species of atoms having same atomic number but different mass number.


Isotope are hazardous because it emits uncontrolled energy in the form of radio active waves which is hazardous to all living things as it can destroy the living tissues that causes fatality or can convert it to cancer.


It is use for welding X­-rays. (If the wind velocity is up the 32 km or 20 miles then work should stop.)


Radioactivity is the spontaneous disintegration of atomic nucleus emits ALPHA particles BETA particles or GAMA rays or electromagnetic rays during this process.


Micro sever or Mille Rem.


The controlled area is calculated evacuated and barricaded with yellow black tapes warning signs a minimum of 4 no. and red or yellow flash lights.


Ensure a competent person is surveying outside the barricaded areas with surveys meters. The crews are observing and following the safety precautions. The controlled areas is calculated evacuated and barricaded with yellow black warning signs a minimum of 4no.s and red or yellow flash lights.


Any area where the radiations dose is more that 0.75 MREM/h (7.5 Micro sever)


Is the instruments used to measure the radiations dose (Radiation Survey Meter)


This badge is worn by the personnel who are exposed to radiation due their nature of duty and this is processed to calculate the received radiation dose of a person during the period normally 1 month of exposure.


Is the chart showing the change in the radioactivity of an Isotope by losing mass by decay in certain period at regular interval of time.


He is one who got formal training in the use of sealed source and X-RAY equipment used in industry radiography.


It should be designed and fabricated according to standards have party certificates two guide ropes damage free lifting gears the load bearing capacity should be written on man basket shackles with cotter pin only to be used.


All slings must be inspected before every use and periodically it should be inspected thoroughly and shall be rejected if found were one third of the original outside the diameter of outside individual wires serves corrosion distortion linking crushing bird caging broken wires.


Mobile Crane
Crawler Crane
Tower Crane
Over Head Crane


Boom,Slings,Shackie,Flyingjib,Antitwoblock,Outerrigger,Mainhoist,Auxillaryhoist,Pulley,Webslings,LMI(Load Movement Indicator).


Crane positions on firm and level ground with wood pads and steel plates. Outriggers are fully extended tires are off the ground. Certified operator and rigger are available safe load indicator is working the check list filled by competent persons.


Is the maximum distance where a certain activities for lifting or rigging jobs in progress.


Safe Working Load is the maximum load that can apply to the lifting tool, safely


Is the documents prepare for planning a critical lift by calculating and considering all factors which is going to effect the lift and there by selecting the correct tools and cranes and ensure the safe lifting procedure to be followed for the particular lift, which is used for lifting and what the safe factor is, where the load is lifted, where it is fitted, size and SWL of each lifting tool used JSA and load-chart are attached with it.


A lift in wich two crane are used for Lifting is called Tandum Lifting.

45) What is excavation?

A man made cut, cavity, trench or depression formed by earth removal.

46) What is trench?

A narrow excavation, where the depth is greater than width

47) What is shoring?

A structure that supports the sides of an excavation and protects against cave-ins.

48) What is different between a flash back arrestor and a check valve?

A check valve allows flow in one direction only. This prevents oxygen reaching acetylene cylinder and acetylene reaching oxygen cylinder in the event of blockage in the torch or line or pressure variations.
But a flash back arrestor prevents reverse flow; stop the flow of flame from reaching the cylinder in the event of a flash back or the temperature exceeds a limit (220 degrees f.)

49) How many type of Fall Protection system?

(1) Guardrail system,
(2) Safety Net system.
(3)Personal Fall arrest system (BODY HARNESS)

50) What is the classis of fire and what type of fire extinguishers are used for them?

Class A. Ordinary combustible materials
Example: Wood, Cloth, Plastic, Rubber
Extinguisher- Water, DCP, Foam, CO2, Halon

Class B. Combustible liquids and gases.
Example: Gasoline, Diesel, Oil, Grease, Oil based paint, tar…
Extinguisher- CO2, Foam, DCP

Class C. Energized electrical equipment
Extinguisher - DCP, FM 200, Halon, Carbon dioxide.

Class D: Combustible metals
Example: Magnesium, Potassium, Zinc, Calcium, Titanium
Extinguisher- Metal x-type, Combustatible metal type

51) What is the responsibility of Fire Watch?

Fire watch is the person design to identify and eliminate fire hazards, alert and extinguish fire incase of any out break of fire and to protect the person and properties from a fire. He is the man to reach first in case of fire by keeping a close watch on such hazardous areas.

52) What is color coding system?

This system followed to inspect and insure the serviceability of tools, equipments periodically ( normally it is monthly ) like fire extinguishers, full body harness, lifting gears, electrical codes and power tools, etc. These things are inspected by competent person and are indicated by putting the color of particular month (this color is decided in advance and is being followed by all people at particular site). The items which are found defective or unserviceable will not be color coded and has to be removed from service.

53) Who can color code?

Competent person

54) What is the maximum distance between two adjacent accesses in a long excavation?

A ladder must be present within 25feet, of employees working in excavation.
In open excavation – At least every 30m on the perimeter, if less than 1.2m deep
At every 7.5m on the perimeter, if more than 1.2m deep

55) When is an excavation considered as a confined space?

If depth is more than 1.2m

56) Who can erect scaffolding?

Certified scaffold

57) Who can inspect the components used for erecting a scaffold?

A competent and certified scaffolding supervisor

58) What is tag system?

A tag system is put on scaffolding, by a competent person, indicating the present condition whether it can be used and whether fall protection needed or not.
Red tag – Do not use (is being erected or dismantled)
Yellow tag – Can use with 100% fall protection (is incomplete or cannot be completed)
Green tag – Safe to use (scaffolding is complete)

59) Who can place a scaffold tag?

Competent person (scaffolding supervisor)

60) What are the details in a scaffold tag?

Location, Maximum loading capacity (kN/m2 or psf), Date erected and date inspected with foreman’s name and signature.

61) In which condition a scaffold cannot be erected?

Extreme weather (strong wind, rain, ice), ground not stable, safe clearance (minimum 10 feet) can’t be maintained with live wire, certified workers and supervisor are not available, permit not available.

62) What is the minimum overlapping of two adjacent planks in a platform?

Not less than 12 inches

63) What is a guard rail system?

A barrier consisting of top rail and med rails, toe board and vertical up right erected to prevent men and materials falling from an elevated work area.

64) What is a toe board?

Barrier secured along the sides and ends of a platform to guard falling of materials, tools, and other objects.

65) What is the minimum height of a toe-board?

Minimum 4 inches

66) What is the height of the top-rail from the platform?

38 inches to 45 inches

67) What are the requirements in placing an access ladder on a scaffold?

Provide access when scaffold platforms are more than 2 feet above or below a point of access.
When using ladders, bottom rung must not be more than 24 inches high. Ladder to be at the correct angle (i.e. Feet out for every 4 feet in height) Ladders are to be tied at both sides not by the rungs. Make sure the ladder extends a safe distance (at least 90cm) above the landing stage. When the horizontal travel distance exceeds 15 meters provide at least two accesses. If the platform is longer, access shall be provided at every 30 meters. The ladder should be free from damage and should be color coded. All access ladders must be tagged.

68) In what circumstances fall protection system has to be used?

If the person could fall more than 1.8 meter then a fall protection system should be used.
Example- Any activity at an elevation more than 1.8 meter such as erection, dismantling or maintenance of scaffolding pipes, equipments.

69) What is the minimum width required for a walk-way?

Minimum width of a walk-way is 18 inches.

70) What material’s can be placed on a scaffold platform?

All types of construction materials which are used for particular construction activity can be kept on scaffolding platform but before keeping the materials and tools required for the work on the platform, we must ensure load bearing capacity of that scaffolding platform. The platform shall not be overloaded and shall be fitted with object protection system like toe board nets etc.

71) What are the requirements for working on a moving scaffold?

Mobile scaffolding shall be plumb, level and square. It shall be moved only by manually pushing or pulling the base. No men, equipment, or materials shall be on the working platform or elsewhere on the scaffolding while it is in motion. Castors shall be locked at all times except during scaffold movement. The temporary foundation or truck set on uneven ground for scaffold movement shall be level and properly secured. The height of the working platform shall not exceed 4 times of the minimum base dimension, if it exceeds this limit outriggers must be installed. A complete guard rail system must be provided. The scaffolding shall be inspected and tagged before use by a competent person.

72) When should we inspect scaffold?

Scaffolding shall be inspected and tagged after completing erection. Also before each work period or where they are altered, adjusted to rain or heavy winds. Thereafter the scaffolding shall be examined at least once in every seven days.

73) What is the angle to fixed the Ladder?

The angle of Ladder is 75deg or ¼.

74) What is the space between the two ladder Rungs?

The gape or space is 12inch or 30cm.

75) With what color a ladder can be painted?

Aluminum ladders and wooden ladders shall not be painted.

76) What is a life-line?

Life line is component that consists of a flexible line that connects to an anchorage at one end to hang vertically or that connects to anchorages at both ends to stretch horizontally and which serves
as a method to connect component of a personnel fall arrest system to the anchorage.

77) How can we calculate the safe anchorage of a life-line?

When life is used they shall be fastened to fixed safe points of anchorage capable of supporting 2300 kilos shall be independent, and shall be protected from sharp edges and abrasion. Safe anchorage points may include structural members (minimum 4 inches structural member or 4inces pipes) but do not include guard rails, vents, other small dia piping system, electrical conduit, outrigger beams or counter weights. It shall be made from 10mm dia wire ropes. Horizontal lifelines shall be installed at the highest feasible point, preferable above shoulder height. This life lines shall be maintained with unloaded sag at the centre no longer than 30cm (12inches) for every 10meters of life line length between attachment points.

78) What is lock-out/tag-out system?

For servicing or maintenance of live equipments or pipe lines where the unexpected energizing or release of energy could cause of injury, lock and tag are place on the isolating device to avoid uncontrolled operation and give details of the lock-out schedule.

79) Abbreviation use for safety?

STARRT - Safety Task and Risk Reduction Talk
COSHH - Control of Substance Hazardous to Health
OSHA - Occupational Safety and Health Administration
CFR - Court of Federal Regulation
OHSAS - Occupational Health and Safety Assessment Series
ELCB - Earth Leakage Circuit Breaker
GFCI - Ground Fault Circuit Interrupter
BSI - British Standard Institute
SWL - Safe Working Load
ANSI - American National Standard Institute
LTI - Lost Time Incident
LMI - Load Movement Indicater
MSDS - Material Safety Data Sheet
TWA - Time Wated Average
STEL - Short Term Exposure Limit
ERP - Emergency Response Plan
ASTM - American Society for Testing and Material
JSA - Job Safety Analysis
LEL - Lower Explosive Limit
UEL - Upper Explosive Limit
PEL - Permissible Explosive Limit
REL ­- Recommended Exposure Limit
PSI - Pound per Square Inches (1 bar = 14.7 psi)
STEL - Short Term Exposure Limit
WBGT - Wet Bulb Globe Temperature
APR - Air Purifying Respirator
ASR - Air Supplying Respirator
SCBA - Self Contained Breathing Apparatus
RSO - Radiation Safety Officer
NFPA - National Fire Protection

80) What is the importance of a tool-box meeting?

The workers can be educated about safe work rules and procedures, and their awareness can be improved on some task.

81) What is an Emergency Evacuation Plan?

It is the procedure to provide concise guidelines for evacuation in case of some emergencies and to identify the emergencies in advance. This also helps us to plan and to define roles and responsibilities of all building custodian, fire wardens and occupants.

82) What is a hydro-test?

It is the test carried out for leak test for pipes, equipments etc, by filling water in these equipments and pipes with some pressure and its joints and connections are checked for ant leak or breakage.

83) What is a hypo-test?

It is the insulation leakage test done for high electrical cables, with high voltage merger.

84) What are the safety requirements for doing a hot work?

Remove all combustible materials from the area (with in 10m), if possible.
Use fire blanket to protect immovable combustible materials and also for welding slugs.
Cover the area with fire blanket for containment of sparks generated while doing hot work.
Provide proper fire extinguisher in sufficient numbers.
Appoint a fire-watch with red jacket, if necessary.
Barricade the area and post proper signage.
Use of proper PPE and damage free
Conduct gas test if presence of combustible gases expected prior to work.

85) What are the benefits of near-miss reporting?

To make analysis of the incident, in order to avoid re-occurrence.
To rectify the cause of those near misses before it turns into accidents.
To identify the deficiencies of site safety performances and find remedial actions.
To improve safety performances by reducing LTA’s incidents and near misses.

86) What is a risk assessment?

Risk assessment is a method of estimating the rate of risk of an activity, by classifying actual and potential consequence and finding out mitigation actions to limit that risk.

87) In what situation “ear protection is needed”?

In the areas, where sound pollution is more than 85 dBA

88) What is the emergency evacuation procedure to follow in the event of a gas release?

Don’t get panic on hearing alarm
Observe the direction of wind flow, proceed out in the cross wind direction to the plant boundary fence and then proceed up wind.
Obey further instructions from emergency response team.
Resume work after getting clearance only.

89) What is an “Assembly Muster Point “?

The area determined and marked, for assemble of people working the area in case of any emergency.

90) What is meant by “Head counting”? What is the purpose?

On hearing emergency alarm, all people have to assemble in “Assembly Muster Point”.
There area supervisor will call his workers with attendance sheet and confirm that nobody is trapped in the site. This procedure is called head counting. Its purpose is to ensure all workers are present in the assembly area, they are safely evacuated and identify the person if anybody is trapped and take necessary actions to rescue these trapped workers.

91) What is heat stroke? What are the different stage through which a person undergoes before he gets heat stroke?

During hot days, due to dehydration, body temperature increases beyond safe limit, because of break down of body’s heat regulating mechanism. Due to this the person collapses and if not taken care off he can even die. This is called heat stroke.
Generally pulse raises 20 beats per minute for each 1 degree C rise in temperature, heat cramps: Exercising in hot weather can lead to muscle cramps, because of brief imbalances in body salt.
Heat exhaustion: further losing of fluid and salt can lead to dizziness and weakness body temperature may rise up to 102 degree F.
Heat stroke: In some cases, extreme heat can upset body’s thermostat, causing body temperature to rise to 105 degree F. or higher. Symptoms are lethargy, confusion and unconsciousness, heat stroke can kill.

92) How is the soil classified? What is the slope to be given for each type of soil while excavating?

The following is a short explanation of soil classifications. You should check the standard for detailed information regarding classifying soils

.Type A soils
Cohesive soils that have an unconfined compressive strength of 1.5 tsf or greater.
E.g., clay, salty clay, sandy clay & clay loam
Type A soils cannot have or be subjected to the following:
Subjection to vibration from traffic, pile driving or similar conditions
Been previously disturbed
Or if it has been subjected to other factors that would change it’s classification

Type B soils

Cohesive soils that have an unconfined compressive strength greater than 0.5 tsf but less than 1.5tsf
E.g., angular gravel, silt, silt loam, sandy loam and previously disrobed soils except those which would be classified as Type C soil
Also includes soils that meet some of the requirements of Type A soils but is fissured or subject to vibration; or dry rock that is not stable.

Type C soils

v Cohesive soils with an unconfined compressive strength of 0.5tsf or less
v E.g. granular soils including gravel, sand and loamy sand
v Also submerged soil or soil from which water is freely seeping or submerged rock that is not stable
Stable rock
v A natural solid mineral material that can be excavated with vertical sides and will remain intact while exposed.
Maximum allowable slopes
v Stable rock: vertical (90degrees)
v Type A: ¾ :1 (53degrees)
v Type B 1:1 (45degreed)
v Type C : 1 ½ : 1 (34degrees)
v ½ : 1 (63 degrees ) slope is allowed for only short term excavations that are 12feet deep or le

93) What are the precautions to be taken while handling and storing compressed cylinders?

  1. Where cylinders are to be kept for an appreciable length of time should be provided to ensure that they cause no hazard to workers or public in the area.

  2. Cylinders should be stored in a well ventilated area-preferable in open air but protected from the weather.

  3. The store should be away from fire risks and source of heat and ignition. Nothing else should be stored in the area.

  4. The cylinders should be stored upright on a firm level, well drained surface free from hollows and cavities. All long grass, weeds etc. should be removed.

  5. Cylinders should be secured so as they are prevented from falling over, when in storage or use.

  6. Cylinders should be segregated within the store according to type and weather full or empty.

  7. Oxygen and oxidizing gases should be separated flammable gases by 6m or by a fire resistant partition.

  8. No electrical apparatus should be installed within a cylinder store unless it is constructed to a suitable standard for the hazard.

  9. No cylinder should be used in a storage area.

  10. Appropriate warning signs “HIGHLY FLAMMABLE”. NO SMOKING”, “FULL/EMPTY” etc. should be displayed.

  11. Suitable fire fighting apparatus should be situated adjacent to the store. Typically dry powder fire extinguishers. These should be inspected and maintained at intervals not exceeding 1 year.

  12. Where cylinders area required to be stored in a compound this should be located not less than 3 meters from any building, site or public access road. The compound fence should be a minimum of 2 meters high, and it should have two means of escape, with the gates opening outwards.

  13. Where it is necessary to take precautions vandalism or theft, suitable protection cages should be used.

  14. Each cylinder should be adequate marked to include the manufacturer’s mark and serial number, together with an indication of the specification to which the cylinder is constructed and its years of manufacture. A date of test and pressure test, together with weight of cylinder and the name of the product, should be displayed.

15)When gas cylinders are to be transported they should be protected from physical damage and the consequences of any leaks that may occur minimized.

16)Move cylinders by hand in proper cylinder trolleys where the cylinder is secured in the trolley.

17)Take great care when lifting cylinders as they can be very heavy and awkward to handle.

18)Before moving any cylinders remove all attached equipment including regulators and safety cap must be provided.

19)The cylinders should be properly supported and secures within the vehicle so they cannot move during the journey. They should be totally within the vehicle and protected from impact.

20)The cylinders should be checked to ensure that the valves are closed and there are no leaks.

21)The vehicle should be equipped with a suitable fire extinguisher. Typically dry powder, minimum capacity 2kg.

22)There should be no smoking within the vehicle while crying cylinders.

23)The driver of the vehicle should be conversant with the load and have written information on the hazards and the action to be taken should any problems occur. The driver should also have training in the operation of the fire extinguisher and any other safety equipment carried.

94) What are the type of fire extinguishers commonly used and briefly, explain each one?

Multipurpose dry chemical, carbon dioxide, halon, wet chemical or foam, pressurized water are the commonly used fire extinguishers.

Multipurpose dry chemical / class “A”, “B”, or “C” fires.2.5-20lb. dry chemical (ammonium phosphate) pressurized to 10.5-18 bar by CO2 gas (8-25 seconds discharge time). Has pressure gauge to allow visual capacity check.5-20ft maximum effective range. Extinguisher by smothering burning materials

Smothering – Cut off oxygen / close the ventilation using fire extinguisher
Starving – Remove the fuel / remove the material going to burn
Cooling – Reduce the heat / use water

Carbon Dioxide – Class “B” or “C” fires 2.5-100lb. of CO2 gas at 150-200 psi (8-30seconds discharge time).
Has NO pressure gauge-capacity verified by weight 3-8 ft. maximum effective range.
Extinguisher by smothering burning materials, Effectiveness decreases as temperature of burning material increases.
Halon – Class “A”,”B”, or “C” fires (smaller sizes ineffective against class “A”). 9-17 lb. Halon 1211 (pressurized liquid) releases as vapor (8-18 seconds discharge time). Has pressure gauge to allow visual capacity check 9-16 ft. maximum effective range. Works best in confined area – ideal for electronics fire due to lack of residue. Extinguishers by smothering burning materials, Fumes toxic if inhaled, Halon is ozone depleting chemical – production halted in Jan ’94.

Wet Chemical or Foam – Class “A”, “B” fires 1.5gal of stored pressure PRX wet chemical extinguishing agent (40 sec. discharge time) 10-12 ft. maximum effective range. On Class “K” fires, don’t use until after fixed extinguishing system has activated, Extinguishes by cooling and forming foam blanket to prevent reigniting.
What is S

95) What is the formula for incident rate?

Number of Record able injuries X 200,000 Number of employees Hour Worked 200,000 is the equivalent of 100 full time employees working for 40 hours per week or 50 weeks per year (OSHA guidelines)

96) What is First Aid and CPR?

Medical aid provide to a victim of an accident scene. This first aid is administered by trained nurse. CPR (Cardio Pulmonary Resuscitation) a first aid given to a person having heart blocked or chocked due to sudden shock.

97) What is Fire?

Chain reaction of FUEL, HEAT, OXYGEN.
A) Fuel any material which can burn like Paper, Rubber, Wood, Oil, Lubricants, Gases, Metals like Phosphorous, Magnesium.
B) Heat or temperature at which the any fuel can ignite this depends on its flash point.
C) Oxygen which is helping in combustion and is present in the air.

98) How Fire can be extinguished?

Remove anyone of the above three elements of Fire. Fire will extinguished,
A) Remove the burning material, the remaining materials will be safe.
B) Cut off the Oxygen by blanketing with foam or Fire blanket or any other materials which
can not burn the oxygen will be cut off and fire extinguished.
C) Remove or lessen the heat with water or use Carbon Dioxide fire cylinder. Never use Water for Electric Fire as water is good conductor of electricity and you will get electric shock if water is used for electric fire.

99) What common type of the fire extinguisher is used for fire?

ABC or Dry Chemical Powder Fire Extinguisher used for Solid, Liquid Gases and Electric Fire.


100) What is a Work Permit?

A written document authorizing employees to carryout a work in a designated area on an equipment specifying the hazards, safety instructions and PPE required for work.


101) What is a Confined Space?

A vessel, column, tank, pit, trench which has limited entry and access and one can not stay inside for long time due to following factors.
Lack of fresh air or Oxygen, Heat, Fumes, Toxicity of storage Contents, Noise any other annoyance, causing disturbance in normal work.

102) What is (a) THLV (b) LEL © UEL?

Threshold Limit Value, Lower Explosive Limit, Upper Explosive Limit

103) What is ASPHYXIANTS?

Chemical gases which can cause suffocation by restricting the uptake of oxygen or by respiratory paralysis or by diluting / displacing oxygen below the levels needed by human body.

104) What is a SCBA?

Self Contained Breathing Apparatus, use in confined spaces or where oxygen deficiency exists or where concentration of toxics gases is harmful to humans.

105) What is toxic Material?

A material or substance which adversely effects body or organs.

106) What are Flammable and Combustible Liquids?

Liquids that give off enough vapors to form an ignitable mixture with air and produce a flame when a source of ignition is present.

107) What is MSDS?

Material Safety Data Sheet

108) What is a Risk Assessment/Hazard Identification Plan?

Identifying hazards and risk involve in a specific job and control measures required to eliminate them or bring them to minimum acceptable limit for the job to be done in safe manner

Before erecting scaffolds assess the work area for existing and for potential future hazards which may impact on the work.

109) What are basic components of scaffolds?

a) Base Plate
b) Sill Boards
c) Screw Jack
d) Couplers
e) Vertical tubes or Bearer also called LEDGERS
f) Horizontal tubes or Ledgers also called STANDARDS
g) Transoms connected across the width
h) Hand rails mid rails
i) Toe Boards
j) Platforms
k) Ladder
l) Diagonal Bracings for stability


110) What are different types of slings used for lifting?

a) Wire rope slings
b) Synthetic/Nylon Webbings
c) Chain Slings

111) When a sling is considered unsafe for use?

  1. 10 wire broken in one rope lay randomly distributed
  2. 05 wires broken in one strand in one lay
  3. 1/3rd of original diameter is scrapping or worn
  4. Kink crushing, bird caging, or other damage or distortion of wire rope structure
  5. Evidence of heat damage
  6. End attachments that are cracked worn or damaged
  7. Hooks open more than 15% of normal throat
  8. Twisted more than 10 degrees from the plane

112) What safety measure are required for SAFE CRANE OPERATION

  1. Crane is to be positioned on level ground
  2. Outriggers fully extended
  3. Mats to be used for stability
  4. Crane radius of swing should be barricaded and no one to cross under the suspended load
  5. Ensure clear of obstructions
  6. Load chart available in the cabin
  7. Qualified Operator and rigger to rig the loads
  8. Only one rigger is authorized to signal the operator
  9. Do not lift the load beyond the rated capacity of the crane
  10. Wind speed not more than 20miles/hr or 32km/hr
  11. Anti two block system working
  12. Load monitoring indicator operational
  13. Telescopic boom free moment
  14. Operators cabin have clear view and not obstructed


114) Why this should be used with electric tools?

To protect the workers from shock in case of current leakage

115) What is the sign of a potable electric tool having double insulated?

(Double square)

116) Why tools having broken insulation must not be used?

To avoid possible electric shock

117) What is meager test?

The insulation break down test is known as meager test

118) Why meager test is necessary for electric tools?

A tool having subjected to harsh use at site needs to be tested for insulation break down to avoid possible electric shock.

119) Why dead man switch should be used on electric tools?

To cut off the power supply to the tool in emergency

120) Why Safety Training is required?

To make the employees familiar with the hazards associated with their work safety orientation and some other trainings is required, also special craft training is required before start of work, safety assessment risk assessment for potential hazards is essential which covers the general hazards and specific hazards associated to the work being undertaken and the control measures applied to eliminate or minimize the potential of harm to the employees, therefore emphasis of accidental loss of resources (Men and Materials) to reduce the direct and indirect costs and loss time delays due to interruptions providing safe and friendly environment for timely completion of projects therefore imparting plays an important role in loss control and it is an idea sound business to have safety culture prevailing on the construction sites.

121) What is LOTO?

Lock out tag out, to lock out specific breakers are used for the maintenance of all equipments

122) What is GFCI?

Ground Fault Circuit Interrupter

123) What is Excavation and Ditches?

Digging of land with Machine or with men

124) What is Confined Space?

Space heaving a limited entrance or egress but that is large enough to bodily entrance and performed the work, i.e.

  1.  Pits sumps
  2.  Vessels
  3.  Boilers
  4.  Tanks Sewers
  5.  D-Excavations
    A) High Temperature
    B) High Noise
    C) Fall from Elevation
    D) Sleeping
    E) Oxygen deficiency

125) What are the scaffoldings and its kinds and it’s Consists?
It is temporary platform
A) System Scaffolding
B) Under Hang Scaffoldings
C) Mobile Scaffolding
D) Bract Scaffolding
E) Tower Scaffolding
F) Tube and Copular scaffolding

Scaffolding Consists

A) Sole Boards
B) Base Plates
C) Posts
D) Ledgers
E) Couplers

  1. Right angle couplers
  2. Right angle Double couplers
  3. End to End Couplers
  4. Adjustable Couplers
  5. Girder Couplers
    F) Top rail
    G) Mid rail
  6. Should be in between top rail and toe boards
    H) Toe Board
  7. Distance between toe board to top rail should be 38 to 43 inches
    I) Bracings
  8. Zigzag bracings
  9. Transverse bracings
  10. Longitudinal bracings and cross bracings

126) What is KENAPI?

To Safe Workers from falling objects we can use KENAPI nets and catch plate forms.

127) Which Permit is use for Vehicles?

Hot Work Permit

128) What is Risk Assessment?

Simply we can defined it with
v What can go wrong
v What can cause its going wrong
v What can we do to prevent it from going wrong

129) What is Evocation?

v Stop the work and switch off equipment and proceed to nearest assembly ground
v Always walk against wind direction
v If you driving a vehicle, stop on road side switch off engine and proceed to assembly area and let the key should inside the ignition point.
v Head count will taken by Safety Officer in assembly area.
v Do not come to work tell all clear alarm sounds.

130) How many types of accident in construction area?

Fatality case
Last work day case
Restricted work case
Medical treatment case
First aid case
Near miss Incident
v An incident, which could cause property damage or personal injury and if we will not stop near miss incidents then can happen an accident.

131) What is Toolbox Talks?

Awareness about work situation to the employee is called toolbox talk
A development of safety bricfings and deal with special issues at the workplace.

132) What is DBA?

The frequency of noise at which we should use ear plug or muffs is 85DBA.
v DBA Decibel at scale A

133) What are LEL and UEL?

v Lower Explosive Limit
v Upper Explosive Limit
Level of Flammable gases or toxic gasses should be zero
Level of Oxygen should be in between 19.5 – 23.5 in volume

134) How many scaffolding tags used in scaffolding?
v Green tag - Scaffolding is safe to work
v Yellow - Use full body harness is required with double Lyn yard
v Red tag - Means scaffolding is unsafe or not able to use (only scaffolder can work)
Note: Safety Harness can bear the weight 2450kg

135) What are the precautions for Welding?
v Hot work permit is required
v Area should be barricaded and warning signage should be placed
v Area should be clean at least 8 meters (free from combustible materials)
v Fire extinguisher and fire blankets should be available
v Trained fire watch man should be available
v Fire water drum should be available
Note: Welder must use complete PPE’s (Welding Helmet, Gloves and Long sleeves shirt)


136) Safety
Safety is a state where risk has been eliminated or reduced to an acceptable level

137) Fire
Fire is a chemical reaction involving rapid oxidation or burning of a fuel. It needs three elements to occur

138) Fuel
Fuel can be any combustible material – solid, liquid, or gas. Most solids and liquids become a

139) Oxygen
Oxygen the air we breathe is about 21 percent oxygen. Fire only needs an atmosphere with at least 16 percent oxygen.

Heat is the energy necessary to increase the temperature of the fuel to a point where sufficient vapors are given off for ignition to occur.

142)Flash Point
Flash Point is the lowest temperature at which a fuel produces enough vapors to ignite in the presence of a heat source.

143) Dust
Dust consists of solid particles and is created by such operations as grinding or sieving of solid materials, controlled detonations and various drying processes.

144) Fumes
Fumes are finely particulate solids which are created by condensation from a vapor, very often after a metal has been converted to the molten state. Fumes are usually highly toxic.

145) Gases
Gas is the formless chemical which occupies the area in which it is enclosed. There are many toxic gases used in industry, such as chlorine.

146) Mist
Mist consists of finely suspended droplets formed by condensation from a gas or the atomizing of a liquid or from aerosols.

147) Vapors
Vapors are the gaseous form of a solid or a liquid, rise in temperature causes the vaporization. Examples are organic solvent vapors’.

148) Liquid
Liquid is a typical example of a liquid, Can be in other forms as droplets or aerosols.

149) Very Toxic
Substances and preparations which in very low quantities cause death or acute or chronic damage to health when inhaled swallowed or absorbed via the skin.

150) Toxic
Toxic substances and preparation that in low quantities cause death or acute or chronic damage to health when inhaled swallowed or absorbed via the skin.

151) Corrosive
Corrosive is substances and preparations that may on contact destroy living tissues.

152) Density
The density of a material is defined as the mass of one cubic meter of material

153) Specific Gravity
We can therefore say that any liquid that will not dissolve (not miscible) in water, with a specific gravity higher than 1, will sink, whilst those with a specific gravity lower than 1 will float on top. For example:
1m3 of water (1000 liters) weights 1000kg
1m3 of aviation gasoline (1000 liters) weight 720 kgs

154) Heat
Heat is a form of energy. Heat can be produced by chemical means, e.g., by burning aviation fuel or by mechanical means, by fiction. Passing electric current through a resistor also produces heat as in an electric fire.

155) Element
Substances that consist of only one type of atom are known as elements. EX. CARBON

156) Molecules
If an element consists of more than one of the same type of atom, chemically bound together, it is known as a molecule. EX. OXYGEN, The term molecule can also be used to describe a substance that is made up of more than one type of atom, water is example.

157) Compound
A mixture is a term used to describe a substance that is made up of more than one type of molecule. EX. WATER

158) Combustion
Combustion is a chemical process. For it to occur, oxygen, usually from the air, must combine with a fuel. A fuel is any substance that will burn and may be in any one of the three states, solid, liquid or gas. EX. SMOLDING OR FLAMING

Flammability Limits:

Flammability Limit
(% Fuel/Air by volume)

Carbon Monoxide

159) Organization Culture
Shop floor representatives, supervisors and managers who meet to discuss general health and safety matters affecting the company

A person’s point of view, or their way of looking at something.

161) Mistakes or Errors
Doing the wrong thing, believing it to be right

162)Influence of peer group
A peer group is a group of individuals of a similar age or background with whom a person mixes in a social context.

163)Work place group
The workplace group is such a group and we behave in accordance with the collective, accepted behavior of the group.

Communication is defined as, imparting, conveying or exchanging information, ideas or opinion by the use of speech, written, or graphics.

165)Written communication
Written a postal service or a notice board

166) Oral or Verbal (SPOKEN) Communication
Oral or Verbal (spoken) a personal interview or telephone system

167) Notices, Posters, Films
Used to draw attention to hazards and risks or safe practices and measures, need to be ‘eye catching’ and relevant.

168) Tool Box Talks
A development of safety briefings and deal with specific issues at the workplace

169) Employee Hand Book:
Key document laying out company policy and certain procedures, Effective as part of induction training

170) Investigation
The purpose of an investigation is primarily to find the cause, with the intention of preventing a recurrence, rather than to blame

171) Reactive Monitoring
Reactive Monitoring, which is used in the investigation of accidents, incidents or dangerous occurrences-After

172) Proactive Monitoring
Pro-active monitoring, which involves checking that standards, practices, procedures and system are being complied with. Before

173) Maintenance Inspections
Inspections involve examining, testing and making repairs/adjustments to such items, often specified by the manufacturer or supplier.

174) Safety Inspection
A formal inspection by a team of inspectors who go round an area or section of work to check on standards; e.g floor condition, HK, warning signs, fire equipment

175) Safety Survey
An in-depth examination of specific procedures such as the introduction of new equipment, or investigating a rise in accident or incident rate

176) Chemical Hazard
Liquids, dusts, fumes, mists

177) Biological Hazards
Exposure to bacteria, viruses and fungi

178) Physical Hazard
Mechanical, noise, radiation, heat etc. also includes ergonomic factors

179) Psychological Hazards
Refers to mental stress

180) Safe Work System
A safe system of work is: a formal procedure which results from systematic examination of a task in order to identify all the hazards

181) Permit to Work
A permit to work can be described as: A formal document giving written.