Complete Safety Q&A Guide
242 essential safety questions and answers for construction and industrial workplaces. Your comprehensive resource for workplace safety standards and procedures.
Safety Standards
Helmet
Z-89.1 (ANSI) 1981
Safety Glasses
Z-87+ (ANSI) 1968
Safety Harness
Z-359.1 (ANSI) & 10.4 ANSI
Safety Shoes
Z-47.1 (ANSI) 1967
Respirator
Z-88.2 (ANSI) 1992
Scaffolding Safety
A-10.4 (ANSI)
"Safety is the control of hazards to obtain any acceptable level of risk, to perform a job properly and avoid incidents and accidents at worksite…!!!"
General Safety (Questions 1-50)
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:
- Watch the job being done
- Break the job down into steps
- Describe the hazards in each step of task
- Identify the desired controls measures
- 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
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.
An undesirable event which has the potential to cause loss.
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.
A man made cut, cavity, trench or depression formed by earth removal.
A narrow excavation, where the depth is greater than width.
A structure that supports the sides of an excavation and protects against cave-ins.
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.)
- Guardrail system
- Safety Net system
- Personal Fall arrest system (BODY HARNESS)
Confined Space (Questions 8-16, 101-107)
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.
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.
Threshold Limit Value, Lower Explosive Limit, Upper Explosive Limit.
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.
Self Contained Breathing Apparatus, use in confined spaces or where oxygen deficiency exists or where concentration of toxics gases is harmful to humans.
A material or substance which adversely effects body or organs.
Space having a limited entrance or egress but that is large enough to bodily entrance and performed the work, i.e., Pits sumps, Vessels, Boilers, Tanks Sewers, D-Excavations.
Fire Safety (Questions 50, 84, 94, 97-99)
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, Combustible metal type
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.
- 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 equipment
- Conduct gas test if presence of combustible gases expected prior to work.
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.
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.
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. Extinguishes by cooling and forming foam blanket to prevent reigniting.
Chain reaction of FUEL, HEAT, OXYGEN.
- Fuel: Any material which can burn like Paper, Rubber, Wood, Oil, Lubricants, Gases, Metals like Phosphorous, Magnesium.
- Heat: Temperature at which the any fuel can ignite this depends on its flash point.
- Oxygen: Which is helping in combustion and is present in the air.
Remove anyone of the above three elements of Fire. Fire will extinguished:
- Remove the burning material - the remaining materials will be safe.
- 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.
- 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.
ABC or Dry Chemical Powder Fire Extinguisher used for Solid, Liquid Gases and Electric Fire.
Scaffolding (Questions 56-73, 125-126, 134)
Certified scaffolders only should erect scaffolding.
A competent and certified scaffolding supervisor.
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)
Competent person (scaffolding supervisor).
Location, Maximum loading capacity (kN/m2 or psf), Date erected and date inspected with foreman's name and signature.
Not less than 12 inches (30 cm).
A barrier consisting of top rail and mid rails, toe board and vertical up right erected to prevent men and materials falling from an elevated work area.
Barrier secured along the sides and ends of a platform to guard falling of materials, tools, and other objects.
Minimum 4 inches (10 cm).
38 inches to 45 inches (96.5 cm to 114.3 cm).
Scaffolding: It is temporary platform.
Kinds of Scaffolding:
- System Scaffolding
- Under Hang Scaffoldings
- Mobile Scaffolding
- Bract Scaffolding
- Tower Scaffolding
- Tube and Coupler scaffolding
Scaffolding Components:
- Sole Boards
- Base Plates
- Posts
- Ledgers
- Couplers (Right angle, Double, End to End, Adjustable, Girder)
- Top rail
- Mid rail
- Toe Board
- Bracings (Zigzag, Transverse, Longitudinal, Cross)
To Safe Workers from falling objects we can use KENAPI nets and catch platforms.
- Green tag - Scaffolding is safe to work
- Yellow tag - Use full body harness is required with double lanyard
- Red tag - Means scaffolding is unsafe or not able to use (only scaffolder can work)
Lifting & Rigging (Questions 36-44, 110-113)
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, Shackle, Flying jib, Anti two block, Outer rigger, Main hoist, Auxiliary hoist, Pulley, Web slings, 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 which two crane are used for Lifting is called Tandum Lifting.
- Wire rope slings
- Synthetic/Nylon Webbings
- Chain Slings
- 10 wire broken in one rope lay randomly distributed
- 05 wires broken in one strand in one lay
- 1/3rd of original diameter is scrapping or worn
- Kink crushing, bird caging, or other damage or distortion of wire rope structure
- Evidence of heat damage
- End attachments that are cracked worn or damaged
- Hooks open more than 15% of normal throat
- Twisted more than 10 degrees from the plane
- Crane is to be positioned on level ground
- Outriggers fully extended
- Mats to be used for stability
- Crane radius of swing should be barricaded and no one to cross under the suspended load
- Ensure clear of obstructions
- Load chart available in the cabin
- Qualified Operator and rigger to rig the loads
- Only one rigger is authorized to signal the operator
- Do not lift the load beyond the rated capacity of the crane
- Wind speed not more than 20 miles/hr or 32 km/hr
- Anti two block system working
- Load monitoring indicator operational
- Telescopic boom free movement
- Operator's cabin have clear view and not obstructed
Safety Abbreviations & Definitions (Questions 79, 136-242)
Safety is a state where risk has been eliminated or reduced to an acceptable level.
Fire is a chemical reaction involving rapid oxidation or burning of a fuel. It needs three elements to occur.
Risk can be defined as the likelihood that the harm from a particular hazard will happen. Risk reflects both the likelihood and severity of the harm.
Risk = LIKELIHOOD × SEVERITY
A planned layout of the workplace is essential if a safe place of work is to be provided.
Accidents are undesired and unplanned events. They may cause personal injury or property damage or both.
Any form of incident which could result in injury or loss but does not.
A hazard can be defined as a situation with the potential to cause harm or danger.
This describes a condition where the quality of a toxic substance absorbed into the body process harmful effects very quickly, i.e. within seconds, minutes or hour.
The term chronic toxicity describes a condition where the harmful effects of a toxic substance absorbed into the body take a very long time to appear-months or perhaps years.
An independent tied scaffold is designed to carry its own mass and the full load of all materials and workers used on the scaffold.