Health and safety engineer/officer interview questions
Q. What is HSE Policy? What are its main parts? And why we need HSE Policy?
The health and safety policy of an organisation is an important legal document that sets out the organisation’s aims with regard to health and safety, explains who is responsible for achieving these aims, and how the aims are to be achieved.
There are three main parts or sections of HSE policy:
1) Statement of Intent- In this section importance of health and safety of the employees for the company, and commitment and leadership regarding health and safety is demonstrated by the top management of the company. Health and Safety aims and objectives are also set in this section.
2)Organisation section- This section highlights the roles and responsibilities from top to bottom within the organisation to achieve the organisational aims and objectives. It shows lines of responsibility and accountability for managing health and safety.
3)Arrangement section- This section provides the detail on how the organisation manages health and safety. It outlines the general and specific arrangements that relate to health and safety management.
HSE policy is one of the primary documents all organisations should have in place. It sets out health and safety objectives, responsibilities and arrangements. Having a good HSE policy delivers many benefits, including clear communication of Health and Safety Management. It is also a legal requirement by many H&S acts and regulations like, Health and Safety at Work Act (1974) and The Management of Health and Safety at Work Regulation (1999).
Q. What is Management System? Identify different types of Management System.
A Management System is the framework of policies, process and procedures used by an organisation to ensure that it can fulfill all the tasks required to achieve its objectives.
Examples of Management System Standards include:
· ISO-9001: Quality Management System (QMS).
· ISO- 14001: Environmental Management System (EMS).
· OHSAS-18001: Occupational Health and Safety Management System Standard.
· ILO-OSH 2001: Occupational Safety and Health Management System.
· ISO-45001: Occupational Health and Safety Management System.
· ISO-50001: Energy Management System.
Q. What is HSE Audit? Identify its types.
HSE audit is the systematic, objective and critical evaluation of an organisation’s health and safety management system. Audit is based on three different types of evidences: Documents and records, Interviews, and Direct observation in the workplace. The objectives of health & safety audit are to evaluate and inform the company that,
· How well it is performing in Health & Safety,
· Whether managers and others meeting the standards set by the company itself,
· Whether the company is complying with the H&S laws.
Types of audit could be:
1) Internal Audit: That is normally performed by internal team to evaluate current status and effectiveness of management system.
2)External Audit: It is second type of audit which is usually conducted by third party certifying body and Insurance companies to evaluate and examine effectiveness of current management system.
Q. What are the sources of evidence / information auditors look for?
Auditors use three methods to gather factual information:
1)Documents and Records (e.g., method statement, HSE policy, procedures, training record, maintenance record, inspection, record risk assessment, incident records, civil claims, accident investigation reports, statutory examinations record etc).
2) Interviews (of workers and management)
3) Direct observation (of the site, activity and behavior of individuals)
Q. Explain the process of Audit OR Explain the steps of an Audit.
Audit is carried out into three steps:
1)Pre-Audit Preparations before the audit starts the following should be defined:
· The scope of the audit- will it cover just health and safety, or environmental management as well?
· The area of the audit – one department, one whole site, all sites?
· The extent of the audit- fully comprehensive (which may take weeks), or more selective?
· Who will be required – auditors will need to be accompanied during their visit and will need access to managers and workers for information-gathering,
· Information-gathering – it is common practice for auditors to ask for copies of relevant documentation before starting the audit so that they can prepare.
2) During the Audit Auditors use three methods to gather factual information:
· Reference to paperwork – the documents and records that indicate what should be happening and what has happened relevant to a particular issue.
· Interviews - word-of-mouth evidence given by managers and workers.
· Direct observation - of the workplace, equipment, activities and behavior.
3)At the End of the Audit – Verbal feedback or presentation to the management team is usually provided at the end of an audit; This verbal feedback will be followed by a written report. The report will make recommendation for improvement and indicate priorities and timescales.
Q. What is Active and Reactive monitoring in terms of H&S?
Active / proactive Monitoring: is the type of monitoring that is performed before any unwanted event for ex. routine safety inspection of the workplace, safety sampling safety survey, safety tour, health surveillance, benchmarking of the performance, etc.
Reactive monitoring: is the type of monitoring that is performed after things gone wrong. For example, investigating accidents and incidents, monitoring the cases of ill-health and sickness absence records.
Q. What is Safety Inspection? AND its Types?
Safety inspection is the process of looking for safety hazards, unsafe acts and unsafe condition at the workplace.
Safety inspections are based on 4Ps:
P- Plant e.g., Machinery, equipment etc.
P- Premises e.g., Workplace and working conditions.
P- People e.g., Acts and behavior.
P- Procedure e.g., System of work.
A safety inspection may be concentrated on one,
more or all above aspects.
Types of safety inspection:
1) Routine inspection of a workplace to determine if general standards of health and safety are acceptable, or if corrective action is necessary.
2)Statutory inspection of an item by a competent person to fulfill a legal requirement (e.g. the annual thorough examination of an item of lifting equipment)
3)Periodic inspection of plant and machinery as part of a planned maintenance programme (e.g. a mechanic inspects the brakes on a lorry on a regular basis to ensure they are not excessively worn).
4)Pre-use checks carried out by workers before they use certain items of plant and machinery (e.g. the start-up checks carried out by a forklift-truck driver).
Q. What is Safety Sampling?
Safety sampling is the technique of monitoring compliance with a particular workplace standard by looking at a representative sample only. If a big enough sample is collected, then there is a strong likelihood that the results of the sample will reflect the results for the workplace as a whole.
For example, if the standard in a large office complex is that all 1,000 fire extinguishers must be inspected annually by a competent engineer, then there are several ways to monitor this standard:
1) Check the maintenance records to ensure each and every fire extinguisher has been signed off.
2) Check all 1,000 fire extinguishers directly by inspecting each one.
3)Check a representative sample of, say, 50 extinguishers selected at random from various locations around the complex. (This method is safety sampling).
Q. What is Safety Survey?
A safety survey is a detailed examination of one particular issue or topic, e.g. a detailed examination of the provision of emergency lighting within a building.
Q. What is Safety Tour?
A safety tour is a high-profile inspection of a workplace carried out by a group or team, including managers, worker representatives, occupational health & safety specialists, engineers and workers from the area.
Q. What is Health Surveillance?
Health surveillance is the method of monitoring workers’ health. E.g., hearing check-ups.
Q. What is Bench marking?
The comparison of an organisation’s performance with others in the industry or sector is known as “bench marking”. This provides an indication of how well the organisation is performing compared to similar companies.
Q. What is the difference between Safety Inspection and Audit?
Safety inspections look for hazards and risks. Meanwhile, safety audits examine whether programs and strategies are meeting a company’s goals. Both are important components of a workplace safety plan.
Q. What is Accident Investigation and Its benefits?
Types of safety inspection:
1) Routine inspection of a workplace to determine if general standards of health and safety are acceptable, or if corrective action is necessary.
2)Statutory inspection of an item by a competent person to fulfill a legal requirement (e.g. the annual thorough examination of an item of lifting equipment)
3)Periodic inspection of plant and machinery as part of a planned maintenance programme (e.g. a mechanic inspects the brakes on a lorry on a regular basis to ensure they are not excessively worn).
4)Pre-use checks carried out by workers before they use certain items of plant and machinery (e.g. the start-up checks carried out by a forklift-truck driver).
Q. What is Safety Sampling?
Safety sampling is the technique of monitoring compliance with a particular workplace standard by looking at a representative sample only. If a big enough sample is collected, then there is a strong likelihood that the results of the sample will reflect the results for the workplace as a whole.
For example, if the standard in a large office complex is that all 1,000 fire extinguishers must be inspected annually by a competent engineer, then there are several ways to monitor this standard:
1) Check the maintenance records to ensure each and every fire extinguisher has been signed off.
2) Check all 1,000 fire extinguishers directly by inspecting each one.
3)Check a representative sample of, say, 50 extinguishers selected at random from various locations around the complex. (This method is safety sampling).
Q. What is Safety Survey?
A safety survey is a detailed examination of one particular issue or topic, e.g. a detailed examination of the provision of emergency lighting within a building.
Q. What is Safety Tour?
A safety tour is a high-profile inspection of a workplace carried out by a group or team, including managers, worker representatives, occupational health & safety specialists, engineers and workers from the area.
Q. What is Health Surveillance?
Health surveillance is the method of monitoring workers’ health. E.g., hearing check-ups.
Q. What is Bench marking?
The comparison of an organisation’s performance with others in the industry or sector is known as “bench marking”. This provides an indication of how well the organisation is performing compared to similar companies.
Q. What is the difference between Safety Inspection and Audit?
Safety inspections look for hazards and risks. Meanwhile, safety audits examine whether programs and strategies are meeting a company’s goals. Both are important components of a workplace safety plan.
Q. What is Accident Investigation and Its benefits?
Accident investigation is the process of determining the immediate and root causes of an accident, so that corrective action can be taken to prevent similar incidents from happening again.
Benefits of investigating an accident/incident:
· It identifies causes of the incidents.
· It identifies corrective actions to prevent re occurrence.
· Records facts of the incident for future evidence.
· Meeting legal compliance.
· Improves staff morale.
· Identifies individuals for disciplinary action.
· It enables risk assessment to be updated.
· Discovers trends.
Q. Explain what are the steps of Accident Investigation.
investigation procedures:
Basically, the accident investigation is done into four steps that are:
Step 1: Gather factual information about the event.
Step 2: Analyse that information and draw conclusions about the immediate and root causes.
Step 3: Identify suitable control measures.
Step 4: Plan the remedial actions.
Q. What is Hazard and types of the hazards?
The inherent property of something or the condition that has the potential to cause harm, injury or property loss.
Hazards can be grouped into five categories:
· Physical
· Chemical· Biological
· Ergonomics
· Psychological
EXAMPLES:
Physical Hazards
Work at height, Electricity, Moving vehicles, Moving parts of machinery, Noise, Vibration, Naked flames, Uneven surface, Poor lighting, Sharp objects, Temperature extremes etc.
Chemical Hazards
Cleaning products, Gases, Solvents, Fumes, Dusts, Smoke etc.
Biological Hazards
Blood or other body fluids, Human waste, Animal and bird droppings, Bacteria and viruses, Insects and animal bites, Fungi etc.
Blood or other body fluids, Human waste, Animal and bird droppings, Bacteria and viruses, Insects and animal bites, Fungi etc.
Ergonomic Hazards
Awkward movements, Repetitive movements, Poor workstation design, Frequent lifting etc.
Psychological Hazards
Over load, Tiredness, Lack of procedure, Violence in the workplace, Bullying and harassment etc.
Q. What is Line of Fire?
“Line of fire” is the military term that describes the path of a discharged missile or firearm. When it comes to health and safety, it may be defined as the path a hazardous object will travel.
There are many objects that have potential to create line of fire exposure, such as:
Suspended load, objects with fall or roll potential, vehicles path, drop zone of working aloft etc.
Q. What is Risk Assessment? Explain it steps?
Risk assessment is the formal process of identifying hazards, evaluating risks and then deciding control measures to eliminate or control those risks to an acceptable level. This can be used to determine whether enough precautions have been taken or whether more should be done to prevent harm.
The aim of the risk assessment is to identify hazards and decide and implement control measures.
The main objective of risk assessment is the prevention of accidents, ill-health and property damage.
Risk assessment is carried out into five steps:
“Line of fire” is the military term that describes the path of a discharged missile or firearm. When it comes to health and safety, it may be defined as the path a hazardous object will travel.
There are many objects that have potential to create line of fire exposure, such as:
Suspended load, objects with fall or roll potential, vehicles path, drop zone of working aloft etc.
Q. What is Risk Assessment? Explain it steps?
Risk assessment is the formal process of identifying hazards, evaluating risks and then deciding control measures to eliminate or control those risks to an acceptable level. This can be used to determine whether enough precautions have been taken or whether more should be done to prevent harm.
The aim of the risk assessment is to identify hazards and decide and implement control measures.
The main objective of risk assessment is the prevention of accidents, ill-health and property damage.
Risk assessment is carried out into five steps:
1) Identify the hazards
Hazards may be identified by:
· Inspecting the workplace
· Asking employees if they have noticed any hazard
· Checking manufacturer’s data sheets and instructions
· Checking accident, near miss and ill-health records
2)Identify the people who might be harmed and how
People may be:
· Employees
· Visitors
· Public
· Vulnerable group like, children, expectant mothers, young workers, new workers, lone workers, individuals with disability etc.
3)Evaluate the risks and decide on precaution
Generally, risk matrix is used to evaluate the risk. Then control measures are decided considering existing control measures that are already being used.
4)Record significant findings and implement them
If a company has five or more employees, a record of the significant findings of the risk assessment must be kept electronically or in writing. It involves recording of, what hazards were found, who are at risk and how, what you are already doing to control the risk and what further action is necessary, by whom and by when.
5)Review and update as necessary
A risk assessment should be reviewed after:
· Any additional control measures have been introduced
· After significant changes to work process, equipment or personnel
· After an accident
· After several near misses
Q. What is Risk Matrix?
Risk Matrix is the matrix that is used during Risk Assessment process to define the level of risk by considering the likelihood and the severity.
Risk is rated as Risk Rating= Likelihood X Severity
The example below is a 5 x 5 matrix. The result will provide a risk rating of 1 to 25
Q. What do you mean by Hazardous Atmosphere?
Q. What is H2S, its health effects and safety precautions for entering into H2S prone areas?
Hydrogen sulphide (H2S) is a colorless, highly toxic and flammable gas with a “rotten egg” smell at low concentration (up to 30 ppm), it has sweet odour at (30 to 100 ppm). At higher concentration or continuous low-level exposure, it is not detectable by the sense of smell. The TLV-TWA, TLV-STEL and IDLH for H2S is 10 ppm,15 ppm and 100 ppm respectively.
It occurs naturally in crude petroleum and natural gas, and can be produced by the breakdown of organic matter and human/ animal wastes (e.g., sewage). It is heavier than air (with density 1.19) and can collect in low-lying and enclosed, poorly ventilated areas such as basements, manholes, sewer lines and underground vaults.
Health effects of H2S:
· Low concentration - irritation of eyes, nose, throat, or respiratory system.
· Moderate concentration - more severe eye and respiratory effects, headache, dizziness, nausea, coughing, vomiting and difficulty breathing.
· High concentration - shock, convulsions, unable to breathe, coma, death; effects can be extremely rapid (within a few breaths).
Safety precautions:
· The air needs to be tested for the presence and concentration of hydrogen sulphide by a qualified person. Necessity of fire prevention should also be determined.
· If gas is present, the space should be ventilated.
· If the gas cannot be removed, use appropriate respiratory protection and any other necessary personal protective equipment (PPE), rescue and communication equipment.
· Atmospheres containing high concentrations (greater than 100 ppm) are considered IDLH and a self-contained breathing apparatus (SCBA) is required.
Q. What is Hierarchy of risk control?
The hierarchy of risk control is a list of control measures, in priority order, that can be used to eliminate or minimize exposure to the hazard. In this system elimination is considered before all other options.
The hazard/risk controls in the hierarchy are, in order of decreasing effectiveness:· Elimination - Hazard elimination is a hazard control strategy based on completely removing a material or process causing a hazard. Elimination is the most effective of the five members of the hierarchy of hazard control. Ex- eliminating work inside confined space.
· Substitution - Hazard substitution is a hazard control strategy in which a material or process is replaced with another that is less hazardous. Ex- Replacing silica sand or coal slag with alternative less toxic blasting material like sodium bi carbonate, Dry ice etc.
· Engineering Control – Engineering controls are strategies designed to protect workers from hazardous conditions by placing a barrier between the worker and the hazard or by removing a hazardous substance through air ventilation. Ex- machine guards, positive ventilation system etc.
· Administrative Control – Administrative controls are training, procedure, policy, or shift designs that lessen the threat of a hazard to an individual. Ex- job rotation, safe system of work etc.
· Personal protective equipment (PPE) – The purpose of PPE is to reduce employee exposure to hazards. It is used in combination with other more effective control measures. PPE does not eliminate the hazard and may result in employees being exposed to hazards if the equipment fails.
Q. What is Safety Sign? Name some standard safety sign.
Safety signs combine shape, color and pictographs to convey specific health and safety information or instructions.
While there are regional variations, the standard safety signs are divided into five categories:
1)Prohibition - directed at stopping dangerous behaviour, e.g. “No Smoking”.
2)Warning - tell people to be careful of a particular hazard, e.g. “Fork Lift Trucks Operating in The Area”.
3)Mandatory action - instruct people to take a specific action, often relating to wearing personal protective equipment, e.g. “Eye Protection Must Be Worn”.
4)Safe condition - identify safe behavior or places of safety, e.g. “First-Aid Station”
5)Fire-fighting equipment - identify particular items of equipment, e.g. “Hose Reels”
Q. Define Personal Protective Equipment (PPE)?
Equipment or clothing that is worn or held by a worker that protects them from one or more risks to their safety or health. E.g., safety boots, safety helmet, hand gloves etc.
Q. What is Collective Protective Equipment (CPE)?
Equipment that protects the workers from one or more risk collectively. It is not worn or held by personnel. It provides protection for every worker in any particular area.
Examples of CPE – safety net, noisy equipment casing, barriers, protective screens etc.
Q. Which is the latest safety regulation / standard?
As of now (June 2018), ISO 45001-2018: Occupational Health and Safety (OH&S) Management System is the latest standard in the field of occupational health and safety, published in March 2018. The standard is based on OHSAS 18001, labour standards, conventions, and recommendations of the International Labour Organization, and national standards. The goal of ISO 45001-2018 is the reduction of occupational injuries and diseases.
Q. What is ILO and OSHA?
ILO (International Labour Organisation) – ILO is a “United Nation’s” agency. The two primary outputs of the ILO are “conventions” and “recommendations”. These set international standards. The ILO is devoted to universal social justice and protecting human rights.187 countries are the members of the ILO.
OSHA (Occupational Safety and Health Administration) – is an agency of the “United States Department of Labour”. The agency is established under the “Occupational Safety and Health Act” in 1971.
OSHA’s mission is to assure safe and healthful working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education and assistance.
Q. What are the responsibilities of workers?
Article 19 of ILO Convention C155 states that all workers and their representatives have to co-operate with their employer so that he can fulfil his safety obligations.
Article 16 of ILO Recommendation R164 says that workers should:
· Take reasonable care of their own safety and that of others who might be affected by their acts and omissions.
· Comply with safety instructions and procedures.
· Use all safety equipment properly and not tamper with it.
· Report any situation that they believe could be a hazard and which they cannot themselves correct.
· Report any work-related accident or ill-health.
Q. What are the responsibilities of an employer?
As per ILO Convention C155 article 16,
· Employers shall be required to ensure, so far as is reasonably practicable, the workplace, equipment, machinery and process under their control are safe and without risk to health.
· Employers shall be required to ensure that, so far as is reasonably practicable, the chemical, physical and biological substances under their control are without risk to health when appropriate measures of protection are taken.
· Employers shall be required to provide, where necessary, adequate protective clothing and protective equipment to prevent risk of accident or adverse effects on health.
Apart from these providing information, instruction, training and supervision to workers and ensuring competency of the workers are also the important responsibility of employer.
Q. what is Self-contained Breathing Apparatus (SCBA), its types and components?
A self-contained breathing apparatus (SCBA) is a type of respiratory protection equipment or device worn by rescuers, fire-fighters and others to provide breathable air in an
SCBA are found in two types:
1)Closed-circuit type (or Re breather) – This type of SCBA filters, supplements and recirculates exhaled gas. CO2 from exhaled gas absorbed and fresh O2 recirculated. Closed-circuit SCBA contains pure oxygen in their cylinder.
2) Open-circuit type – This type of SCBA are filled with filtered, compressed air rather than pure oxygen.
Components of SCBA:
SCBA typically has three main components –
1)High pressure tank (e.g., 153 to 310 bars) - air cylinders are made of aluminium, steel or of a composite construction (usually carbon-fibre). Carbon fibre cylinders are the lightest in weight, therefore preferred,
2)A pressure regulator,
3)And an inhalation connection (e.g., mouth-piece, mouth mask or face mask).
Q. What is ELSA?
An Emergency Life Support Apparatus (ELSA) is a type of breathing apparatus used in an emergency situation to escape from a confined space or building following a fire, chemical accident or explosion. An ESLA is needed when breathable air is insufficient or highly contaminated.
An ELSA provides a constant flow of breathable air to the user for about 10 to 15 minutes. Generally, it consists of the following parts:
· A pressure release valve, pressure gauge and whistle attached to cylinder’s neck.
· A hood with visor and/or a mouthpiece connected to a pipe that supplies air from the cylinder
· A carrying pouch with a waist belt or neck strap
Q. What is escape respirator?
Escape respirators are similar as ELSA in terms of their use. It is also the small size respirator which is used in an emergency to escape from a highly contaminated zone.
Q. What is TLV, PEL, REL and IDLH?
TLV (Threshold Limit Value) – The threshold limit value of a toxic gas or chemical is believed to be a concentration level to which a worker can be exposed day after day for a working lifetime without adverse effects. The TLV is a recommendation by American Conference of Governmental Industrial Hygienists (ACGIH), with only a guideline status.
PEL (Permissible Exposure Limit) –Permissible exposure limit is similar to TLV, but it has regulatory status. PEL is published and enforced by OSHA.
REL (Recommended Exposure Limit) – The National Institute for Occupational Safety and Health (NIOSH) publishes recommended exposure limits (REL) which OSHA takes into consideration when promulgating new regulatory exposure limits.
IDLH (Immediate Dangerous for Life or Health) – OSHA defines the term IDLH as "an atmosphere that poses an immediate or delayed threat to life, would cause irreversible adverse health effects, or would impair an individual's ability to escape from a dangerous atmosphere."
Note: some materials, for example, hydrogen fluoride gas and cadmium vapor, poses no immediate adverse effect, but are followed by sudden fatal collapse after 12 to 72 hours.
Q. How many types of TLV?
There are three types of TLV for toxic gases and chemicals:
1)Threshold Limit Value – Time-Weighted Average (TLV-TWA): Average exposure on the basis of 8h/day, 40h/week work schedule.
2)Threshold Limit Value – Short-Term Exposure Limit (TLV-STEL): Spot exposure for a duration of 15 minutes, that cannot be repeated more than 4 times per day with at least 1 hour gap between exposure periods.
3)Threshold Limit Value – Ceiling Limit (TLV-C): Absolute exposure limit that should not be exceeded at any time.
Q. What is LEL/LFL and UEL/UFL?
LEL (Lower Explosive Limit) / LFL (Lower Flammability Limit) - is defined as the lowest concentration (by percentage) of a gas or vapor in air which can lead to flame propagation, detonation or an explosion, in presence of an ignition source (spark, flame, heat).
UEL (Upper Explosive Limit) / UFL (Upper Flammability Limit) - is defined as the highest concentration (by percentage) of a gaseous or vaporized fuel, in air, which can lead to flame propagation, detonation or an explosion, in presence of an ignition source (spark, flame, heat).
Note: Concentrations lower than the Lower Explosive Limit are 'too lean' to burn; those above the Upper Explosive Limit (UEL) are too rich to burn. Fuels will burn, only if their concentration in air is within the range of their LEL and UEL.
Q. What is flash point, auto ignition temperature and Fire point?
Flash point – Flash point is the lowest temperature at which a liquid gives off enough vapours to form a mixture with air that can be ignited, when given an ignition source.
Auto ignition temperature – is the temperature at which vapour ignite spontaneously without an ignition source.
Fire point – is the lowest temperature at which vapours of the material will keep burning after being ignited and the ignition source removed.
LEL, UEL, Flash Point and Auto ignition temp. of different combustible and flammable substances:
Q. Which kinds of liabilities an employer can face?
An employer could face a range of liabilities for not maintaining health and safety standards in the workplace. Liabilities may range from direct and indirect costs to legal actions against an employer if employer’s negligence led to an accident.
Some examples of liabilities are:
· Fines in criminal court.
· Compensation payable to the victim.
· First-aid treatment.
· Workers sick pay.
· Repair to or replacement of damaged equipment.
· Lost production time while dealing with the injury.
· Loss of staff from productive duties in order to investigate the incident, undertake hospital visits, deal with relatives of victims and court proceedings.
· Loss of staff morale.
· Project delay that leads to loss of goodwill of customers and penalty for failing to meet delivery dates.
· Damage to public image and business reputation.
Q. What is Permit-to-Work (PTW) / Safe Work Permit? And name different types of Work Permit?
A permit-to-work system is a formal written system used to control certain types of work that are potentially hazardous. Basically, it is a formal written permission to perform a particular job specially for significant risk activity. It specifies the work to be done and the precautions to be taken. It is a formal part of safe system of work. It allows work to start only after safe procedures have been defined and they provide clear record that all foreseeable hazards have been considered.
Types of permit-to-work:
· HOT WORK PERMIT (Hot Work Permit is required for carrying out any hazardous activity or those produces sufficient heat to cause fire in a inflammable air-vapour mixture. E.g., welding, cutting, brazing, grinding, vehicle entry into hazardous area, etc.).
· COLD WORK PERMIT (This permit is required for carrying out any activity inside plant that are non-critical in nature and does not produces sufficient heat to ignite a flammable substance. E.g., cleaning, manual handling, cold work at height etc.).
· CONFINED SPACE ENTRY PERMIT (Confined Space Entry Permit is required for entry into any confined space.).
· EXCAVATION PERMIT (Excavation permit is required for carrying out any excavation inside plant.).
· RADIOGRAPHY PERMIT (Radiography Permit is required for Radiographic Testing).
· ROAD / SITE CLOSURE PERMIT (for closure of road/cutting of road or blockage of main roads is required in a section or unit.).
· ELECTRICAL ISOLATION AND ENERSISATION PERMIT (this permit is required for all electrical isolation and energisation of electrical equipment.).
Note: In some organisation Confined space Entry Permit and Excavation Permit are called Authorizations or associated certificates with the major permits.
Works exempted from requirement of permit:
· Routine works carried out into the workshop (except Hot Work Permit)
· Routine testing of samples and handling chemicals in Quality Control laboratory (except Hot Work Permit)
· Jobs carried out during emergencies (fire/explosion, uncontrolled release of hazardous chemicals, rescue, natural disaster etc.) to control the emergency.
Q. What are general conditions / requirements of Permit-to-Work?
· Display the permit at work site with associated authorisations.
· Separate permits are required so different maintenance crafts and jobs.
· Only authorised personnel holding valid “work permit issuer/executer” card can sign permit.
· Only field operators/contractors with work “permit awareness training” can sign respective column.
· Only authorised gas testers holding valid certification for gas test can sign gas test section.
· Issuer may authorize work only if the gas tests results are within the permissible range.
· Field operator must check site and sign the permit before start of the work.
· Executor must provide adequate supervision and must be always present during critical work.
· Executor must ensure providing all recommended protective before starting work and compliance to all permit conditions. He must ensure his people are wearing appropriate PPE
· Suspend all work in case of plant emergency or accident.
· Issuing division and safety personnel have the right to stop the job any time on safety reasons
· Field operator shall monitor permit conditions and site conditions frequently.
· Executor must renew the permit if the work is “stopped” or “not started” for over 2 hrs.
· All tools and equipment shall be secured, and personnel protected from falling objects.
· Do not anchor to or suspend loads on process piping.
· Do not use scaffolds without valid green scaffold tag.
· Do not use wooden planks in running units.
· Close the permit by completing relevant section of original and field operator copy. Keep in file for 1 month.
Q. How many sections are in the Work Permit?
Formats and sections of Work Permit vary from company to company. But the typical sections of a Work Permit are:
Section 1- Exact Location and Description of Work.
Section 2- Work is Critical (Yes or No, if Yes then, Fire station informed? Issuer & Executor jointly checked work site? Risk Assessment done & attached?)
Section 3- Safety Requirements, it has 3 columns:
· Has the equipment been
Isolated, depressurized, blanked, blinded, disconnected, flushed, purged, drained?
· Engine with exhaust spark arrester & valid safety certificate.
· Expected residual hazards.
· Protection measures.
Section 4- Gas Test and Electrical Isolation.
Section 5- Authorization/Renewal (It is safe to proceed with this job).
Section 6- Permit Closure (Agreed, site was checked and found safe).
Q. What is Scaffolding? And its Types?
Scaffolding or Staging is a temporary platform constructed for supporting both men and materials Scaffolds are widely used on site to get access to heights and areas that would be otherwise hard to get to.
Types of scaffolding:
1. Tube and coupler type Scaffold
2. Trestle Scaffold
3. Patented or Ready made Scaffold
4. Suspended scaffold
5. Cantilever Scaffold
6. Mobile Scaffold
Q. What are the potential hazards / risks of working on scaffolding?
There are several hazards to watch out for when using scaffolding:
· Unsecured and excessive over hanged planks cause workers to fall.
· Unsecured or overloaded scaffold can collapse
· Missing toe boards and guardrails can cause workers to fall and the materials falling on workers.
· Scaffolding planks can also break if overloaded
· Overhead electrical lines can cause electrocution
· Bad housekeeping on scaffolding platform also create risks of slip, trip and fall.
· Unsafe access such as ladders.
· Bad whether condition effects integrity and sustainability of scaffold.
Q. What are the safety measures that can be taken to avoid risks of using scaffolds?
· Ensure that scaffold is designed by qualified person.
· Ensure the use of base plate, guard rails, toe board, bracing etc.
· Ensure providing safe access.
· Scaffold must be secured.
· Ensure users are trained and all the foreseeable risks of using scaffold are communicated.
· Ladders used in scaffold for access should be secured and extended at least 3 feet from the landing platform.
· Inspect the scaffold every week and on daily basis before use and whenever exposed to adverse whether condition such as rain and heavy wind.
· There should be tag system to identify when the scaffold is safe to use.(Red tag- do not use, Green tag- safe to use, yellow tag- caution)
· Scaffold must not be overloaded.
· Work on or from scaffolds is prohibited during storms or high winds unless a competent person has determined that it is safe for employees to be on the scaffold and those employees are protected by a personal fall arrest system or wind screens.
· The area below the scaffold to which objects can fall, shall be barricaded, and employees shall not be permitted to enter the hazard area
· Provide fall protection system in the form of full body harness or safety net.
Q. What are the standard safety requirements for scaffold erection / design?
Some of the standard safety requirements, related to scaffold erection, those are mentioned in OSHA standard are:
· Scaffolds shall be designed by a qualified person and shall be constructed and loaded in accordance with that design.
· Any gap on the scaffold platform shall not be more than 1 inch.
· The front edge of all platforms shall not be more than 14 inches from the face of the work, unless guardrail systems are erected, and/or personal fall arrest system is used.
· Each scaffold platform and walkway shall be at least 18 inches wide.
· On scaffolds where platforms are overlapped to create a long platform, the overlap shall occur only over supports, and shall not be less than 12 inches (30 cm) unless the platforms are nailed together or otherwise restrained to prevent movement.
· Wood platforms shall not be covered with opaque finishes, except that platform edges may be covered or marked for identification.
· Scaffold components manufactured by different manufacturers shall not be intermixed.
· Footings shall be level, sound, rigid, and capable of supporting the loaded scaffold without settling or displacement.
· Unstable objects shall not be used to support scaffolds or platform units.
· The employer shall provide safe means of access for each employee erecting or dismantling a scaffold where the provision of safe access is feasible and does not create a greater hazard.
· Scaffolds and scaffold components shall not be loaded in excess of their maximum intended loads or rated capacities.
· The use of shore or lean-to scaffolds is prohibited
· Any part of a scaffold damaged or weakened shall be immediately repaired or replaced.
· Scaffolds shall be erected, moved, dismantled, or altered only under the supervision and direction of a competent person.
· Platforms shall not deflect more than 1/60 of the span when loaded.
· Guardrail systems shall be installed along all open sides and ends of platforms.
· The height of top rail are 42 inches, plus or minus 3 inches, above the walking-working surface. And mid rail height shall be 21 inches.
· Ladder shall be placed at1:4 ratio and extended at least 3 feet above the platform for safe landing of workers.
· Workers involved in scaffold erection must be trained.
Q. What are the capacity requirement for scaffold?
Each scaffold and scaffold components must support without failure its own weight and at least 4 times the maximum intended load applied to it. (suspended scaffold must support its own weight and at least 6 times of intended load).
Q. How wide does the work area need to be on scaffold?
Each scaffold platform and walkway must be at least 18 inches wide, otherwise guardrails and/or personal fall arrest system must be used.
Q. What is the base width to height ratio of scaffold?
The base width to height ratio of scaffold is 1:4. For example if base width is 2 m, the maximum height would be 8 m.
Q. Can you tell me the names of different scaffold components?
Typical scaffold components include:
· Sole plate- first component of scaffold putted on ground to distribute the load.
· Base plate/jack- in which the standard or vertical tube is fitted. it provides stability to scaffold.
· Standard- the vertical scaffold poles that bear weight of the scaffolding.
· Coupler- a fitting used to join components together.
· Plank/board- they are used to make working platform.
· Mid rails & guardrails- the scaffolding tubes fixed to the edges of scaffold to prevent fall of persons.
· Toe boards- they are planks or boards fitted to the edges to prevent material fall.
· Braces- they are scaffold tubes fitted diagonally or horizontally to provide strength to the scaffold.
· Transoms- a horizontal cross-section load-bearing component which holds the boards or decking unit.
· Ledgers- a horizontal brace attached 90 degree to the transoms.
· Ladder- used to get access to the scaffold.
Q. What is transom?
Transom is a horizontal cross-section load-bearing component which holds the boards or decking unit.
Q. How often should a scaffold be inspected?
A scaffold used for construction should be inspected before it is used for the first time and then every seven days. It should also be inspected each time it is exposed to conditions likely to cause deterioration eg. Following adverse weather condition or following substantial alteration.
Q. How high should the guardrails on a scaffold be?
The top guardrail should be a minimum of 950mm above the working platform and any gap between top rail and the mid rail should not exceed 470mm.
Q. What is the maximum height a ladder can be used?
There is no maximum height for using a ladder. However, where a ladder rises 9 meters or more above its base, landing areas or rest platforms should be provided at suitable intervals.
Q. What are the common hazards of crane lifting activity?
Hazards of crane lifting operation include:
· Crane toppling.
· Suspended load falling.
· Striking by moving load.
· Crane collapse.
· Crushing between load and structure.
· Equipment failure.
· Contact with overhead power lines.
· Pinch point.
Q. What safety precautions should be taken for crane lifting or rigging operation?
Some of the typical precautions for crane lifting are:
· Prepare lifting plan.
· Carry our JSA (Job Safety Analysis) or JHA (Job Hazard Analysis), or JRA (Job Risk Analysis) or STA(Safety Task Assignment).
· Place the crane on firm and level ground, extend the outriggers properly and use mats.
· Cordon off (barricade) the lifting zone and place the warning signages.
· See the load chart and do not overload the crane.
· Inspect the crane and all tools and tackles prior to use.
· Check the validity of crane/tools third party inspection certificates, safety certificate of crane, and fill the daily checklist after carrying out visual inspection.
· Ensure crane operators and riggers are competent holding relevant cards and certificates.
· Lifting should not be performed in bad weather conditions
· Use tagline to control the load.
· Provide appropriate communication device for signal.
· Isolate the power if working near overhead power line.
· Use rigging pad to prevent load slippage and cuts to the sling.
· Wear personal protective equipment like safety helmet, safety shoes, hand gloves etc.
Q. What is Critical Lift?
According to OSHA 1926.751, critical lift means a lift that meets one of two criteria:
1) The load exceeds 75% of the rated capacity of the crane or derrick, OR
2) The load requires the use of more than one crane or derrick.
Q. What do you mean by Lifting Plan or Lift Study?
Lift plan is a document that provides information about lifting activity. It is an important planning process that will identify all hazardous situations that might be encountered during lifting.
Components of lifting plan/information gathered in the lifting plan:
· Overview of the area (atmospheric and environmental condition of the site, objects in the vicinity including plants and overhead power cables etc.).
· The weight of lift (load).
· Centre of gravity of the load being lifted.
· The dimension of lift.
· Crane being used and its lifting capacity.
· The rigging tools and tackles being used (shackles, slings, chain blocks, etc.).
· Boom and sling angle.
· Evaluate hazards to determine consequences resulting from collision, upset or load drop.
· Good rigging practices etc.
Q. What is pre-engineered lift?
A pre-engineered lift is a repetitive or routine lift performed for assembly or disassembly of components or systems in which the item to be lifted are identical in terms of dimensions, weight, centre of gravity, load path, attachment to the lifting equipment and selection of the lifting equipment. In this type of lift all items can be lifted in adherence to a specific routine step-by-step procedure that eliminates rigging decisions or calculations.
Q. How many types of cranes are there?
Cranes can be categorized into two ways:
1 a) Hydraulic crane (e.g., telescopic mobile crane, rough terrain crane, truck mounted crane or loader).
b) Mechanical crane (e.g., crawler crane tower crane, overhead or gantry crane, derricks).
2 a) Mobile crane (e.g., telescopic boom mobile crane, crawler, rough terrain crane, truck mounted crane).
b) Fixed crane (e.g., tower crane, overhead/gantry/suspended crane)
Note: crawler comes into both hydraulic and mechanical type.
Q. How many types of crane booms are there?
There are mainly three types of booms being used in cranes:
1. Telescopic Boom
2. Lattice Boom
3. Articulating Boom
Nylon Slings capacity (WLL)
Q. What are the various sling hitches used during lifting and their effect on Working Load Limit?
Mainly three types of sling hitches are used to attach load to the crane hook.
1. Vertical hitch
2. Choker hitch
3. Basket hitch
Effect of sling hitches on WLL
Vertical hitch- When a sling is used in a vertical hitch, full lifting capacity of the sling is utilised.
Choker hitch- In case of choker hitch, 25% of the capacity is decreased due to stress created at the choke point.
Basket hitch (90°)- The capacity of the sling in this hitch is twice that of the same sling in a vertical sling because two ends (legs) of the sling function as they were two separate slings. It requires two hooks or a spreader to attach both end of the sling.
Basket hitch (less than 90°)- When slings or sling legs are used at an angle during a lift, the sling capacity is reduced. Lesser the angle, lesser the capacity. There are Sling Angle Factor that is used to calculate the capacity.
Q. What is Safe Working Load (SWL)?
SWL or Rated Capacity or MRC (Maximum Rated Capacity) is the maximum gross load which may be applied to the crane, hoist or winch.
Q. What is Working Load Limit (WLL)?
Working Load Limit is the maximum load which may be applied to the lifting components including shackles, hooks, chain blocks, slings etc.
Formula for calculating WLL of slings at specified angle
WLL=vertical hitch WLL X no. of legs X sling angle factor
Example:
WLL of grey nylon sling with 2 legs at an angle of 60°
WLL=vertical hitch WLL x no. of legs x sling angle factor
= 4000kg x 2 x 0.866
=6928 kg
Wire Rope WLL
Q. Can you tell the name of some Industrial Vehicles.
Some vehicles those are used in an industry are:
cranes, trailers, dumper trucks, fork lifts, excavators half lorries, pickups, water and oil tankers etc.
Q. What is an Emergency and its types?
A serious, unexpected, and often dangerous situation that requires immediate action.
Types of Emergency:
· Fire/explosion emergency.
· Dangerous chemical spillage.
· Toxic gas release e.g., H2S
· Natural calamities e.g., flood, earthquake etc.
· Security threats.
Q. What is Emergency Planning?
Emergency planning can be defined as a control measure. It can control the accidents safe guard people and provide information to media. An emergency plan specifies procedures for handling sudden or unexpected situations.
Q. What is Work Method Statement/ Standard Operating Procedure? and what headings it consists?
A work method statement, sometimes called a "safe system of work", is a document that details the way a work task or process is to be completed. The method statement should outline the hazards involved and include a step by step guide on how to do the job safely. The method statement must also detail which control measures have been introduced to ensure the safety of anyone who is affected by the task or process.
Typical headings of Method Statement:
· Title e.g., Method Statement.
· Brief description of work, task or process.
· Company details (name, address etc.).
· Start & completion date.
· Site address and contact details including emergency numbers etc.
· Document no., issue date, revision date etc.
· Permit to work.
· Staff, training and PPE.
· Risk assessments.
· Machinery/plant shutdown and lock off procedures
· Site access and egress.
· Material handling.
· Scaffold and access to height.
· Welfare and first-aid. Etc.
Q. What is Fire?
Fire is the chemical chain reaction between three element fuel, heat and oxygen (air).
Q. What is Fire Triangle/Combustion Triangle?
The fire triangle is the illustration of three essential elements of fire (Fuel, Heat and Oxygen). In absence of any one element triangle will not form i.e., fire will not occur.
Q. What are the methods for extinguishing the fire?
There are three main methods to extinguish a fire. These involves removing one of the essential elements of fire (Fuel, Heat, Oxygen):
1) Cooling – removal of Heat (by water generally for class A fire)
2) Smothering – removal of Oxygen (by using CO2 or DCP)
3) Starvation – removal of Fuel (by cutting fuel supply)
Q. What is the difference between flammable and combustible substances?
According to NFPA 30 Classification of flammable and combustible substances:
Substances which have a flash point less than 100.0 °F are called flammable — whereas fuels having a flash point above that temperature are called combustible.
Further classification:
Flammables:
Class 1A – Flash point < 73 °F, Boiling point < 100°F
Class 1B – Flash point < 73 °F, Boiling point > 100°F
Class 1C – Flash point > 73 °F < 100°F
Combustibles:
Class II – Flash point > 100 °F < 140 °F
Class IIIA – Flash point >140 <200 °F
Class IIIB – Flash point > 200 °F.
Q. What are the US and UK based classification of fire?
UK based classification of fire:
Class A – Solid fire (wood, paper, textiles etc.)
Class B – liquid fire (diesel, kerosene etc.)
Class C – Gas fire (propane, methane etc.)
Class D – Metal fire (sodium, potassium etc.)
Class F – Kitchen fire (cooking fats and oil)
Note: Previously there was a class E – Electrical fire, but later this class removed, considering electricity as a heat source.
US based classification of fire:
Class A – Solid fire
Class B – Liquefiable solid (waxes, plastics etc.), Liquid and Gas fire
Class C – Electrical fire
Class D – Metal fire
Class K – Kitchen fire.
Q. What is fire extinguisher, its types and application of each, and colour coding for different fire extinguisher?
A portable device that discharges a jet of water, foam, gas, or other material to extinguish a fire is called fire extinguisher.
Types of fire extinguishers and their application:
Water type extinguisher – Water fire extinguishers have a class A rating and are suitable for fighting fires involving solid combustibles such as wood, paper and textiles.
AFFF Foam type extinguisher – AFFF (aqueous film forming foam) foam fire extinguishers are highly effective on class A and class B fires (the foam agent helps to prevent re-ignition). Some foam extinguishers have been dielectrically tested to 35000 Volt (35kV) and can be used on or near electrical appliances.
Carbon dioxide (CO2) type extinguisher – They are ideal for electrical fires, as CO2 is not a conductor and they do not leave behind any harmful residue.
ABC Dry chemical powder type extinguisher – ABC powder fire extinguishers are extremely versatile and can be used on class A, class B, class C and electrical fires.
Water mist type extinguisher – They are highly effective on class A,B,C,F and electrical.
Wet chemical type extinguisher – Wet chemical fire extinguishers are designed specifically for use on class F kitchen fire
Colour coding for fire extinguishers:
Water type – Red
AFFF Foam – Cream
Carbon dioxide – Black
ABC Powder – Blue
Water mist – White
Wet Chemical – Yellow
Q. What is PASS method?
PASS is the acronym for Pull the safety pin, Aim nozzle at base of the fire, Squeeze the lever and Sweep side to side. This is fire extinguishing method or steps that is followed to extinguish a fire using fire extinguishers.
Q. What depth of an excavation is considered as confined space?
Practically, the excavation in an area (where oxygen deficiency or hazardous atmosphere exists or could reasonably be expected to exist) that is greater than 1.22 m in deep is considered as confined space.
Q. What is the depth of a confined space?
Depth of confined space is not defined. But generally the space that is greater than 4 feet(1.22m) in deep and meeting all other criteria of confined space, considered as confined space.
Q. What is Induction training?
Induction training is the form of introduction for new employees about the company, work activitivities, company’s health & safety policy, current hazards involved in different sites, general laws of the country if workers are from other place, emergency evacuation and fire safety etc. to enable them work safely.
Q. What is toolbox talk?
A toolbox talk is a brief informal group discussion that focuses on hazards involved in a particular job and safety precautions to be taken to minimize the risks.
toolbox talk can be organized on daily basis to promote site safety culture as well as to facilitate health and safety discussions on the job sites.
Q. What are the hazards and safety precautions for working with the electricity?
Hazards of electricity:
· Electric shock
· Fire and explosion
· Arcing
· Direct and indirect burns
· Secondary effects like fall from ladder as a consequence of electric shock
· Ultra violet radiation from arcing.
Safety precautions for electricity:
· Suitable electrical equipment should be selected for the purpose.
· Power should be isolated before working on electricity and lock-out tag-out procedure should be followed.
· Electrical works should be restricted to the competent workers only.
· All electrical installations, equipment and appliances should be subject to user checks, formal visual inspections and testing.
· Electrical equipment should not be used in wet condition.
· Various protective systems should be used such as fuses, RCB, ELCB, GFCI, earthing etc.
· Non-conductive tools to be used while working with electricity.
· Work permit system should be followed.
· Workers should wear appropriate PPEs such as electric shock proof gloves, boots etc.
Q. What are four legs of fire safety?
1. Fire protection
2. Fire prevention
3. Quantity control
4. Preventive Maintenance
Q. What is the difference between fire prevention and fire protection?
Fire prevention is about taking steps to prevent a fire from happening. For example regular inspection, provision of booths for hot work, housekeeping, properly storing materials etc.
Fire protection is the combination of different fire safety equipment and procedures that are used to control the fire and to protect the people and property. Fire protection often includes equipment like fire alarms, extinguishers and fire sprinkler system.
Q. What is CPR and process of giving CPR?
CPR (Cardiopulmonary Resuscitation) It is a life saving medical procedure which is given to someone who is in cardiac arrest. It helps to pump blood around person’s body when their heart unable to do this. It combines chest compression and artificial breathing.
Steps to follow:
Step 1- shout for help and bring the victim to the safe place.
Step 2- check for response by shaking victim’s shoulder and asking something.
Step 3- check for normal breathing by looking, listening and feeling. If the person is breathing normally then put them in recovery position and call ambulance.
If the victim is not breathing:
Step 4- ask someone to call ambulance immediately.
Step 5- Place one hand on the person’s forehead, gently tilt their head back, then lift their chin using two fingers of your other hand under their chin, this is for opening airways.
Step 6- start CPR:
· Kneel next to the person.
· Place the heel of one hand in the centre of their chest. Place your other hand on top of the first. Interlock your fingers.
· With straight arms, use the heel of your hand to push the breastbone down firmly and smoothly, so that the chest is pressed down between 5–6 cm, and release.
· Do this at a rate of 100 to 120 chest compression per minute – that’s around 2 per second.
· Give 30 chest compression.
· Open the airway again by tilting the head back and lifting the chin. Pinch the soft part of the person’s nose closed.
· Give 2 rescue breath.
· The person’s chest should rise and fall. Keeping the person’s head back and the chin lifted, take your mouth away, take another normal breath, and give a second rescue breath. The two breaths should take no longer than five seconds.
· Repeat 30 compression and two rescue breaths until ambulance arrives.
Q. What is smoke detector?
Smoke detector: A smoke detector is a device that senses smoke, typically as an indicator of fire.
Types:
Ionization smoke detector – ionisation smoke detector uses a radio isotope, typically americium-241 (an alpha emitter) to ionize air. A difference is detected in ionising process due to smoke and an alarm is generated.
Photoelectric or optical smoke detector – It contains a source of infrared, visible, or ultraviolet light (typically incandescent light bulb or LED), a lens, and a photoelectric receiver (typically a photodiode). The light emitted by the light source passes through the air being tested and reaches the photosensor. The receives light intensity will be reduced because light is scattered due to smoke particles. The circuit detects the intensity reduction and generates the alarm.
Carbon monoxide and carbon dioxide detection – fire produces carbon monoxide and carbon dioxide, and they can be detected through these detection systems. They are particularly suitable for dusty and dirty environment where ionising and optical detection systems tend to give false alarm.
Q. What is Fire Sprinkler System?
A fire sprinkler system is an active fire protection method that consists pressurised water supply through piping distribution and provides water flow through the sprinkler heads when fire is detected.
Sprinkler Head
Sprinkler head is a component of the fire sprinkler system that discharges water when fire is detected or temperature of that location exceeds the predetermined level. It has color-coded heat sensitive glass bulb filled with liquid (mixture of alcohol and water or glycerine and water) that works as a plug which prevents water from flowing. The color of the bulb indicates the activation temperature. When temperature around the sprinkler head exceeds the activation temperature, the bulb breaks and water starts flowing through the head.
Colour-code and activation temp. of bulb
Orange - 57 °C Green - 93°C
Red - 68°C Blue - 141°C
Yellow - 79°C Purple - 182°C
Q. How will you define Hazardous Waste?
The waste that is dangerous or potentially harmful to our health or the environment is known as hazardous waste.
Fire is the chemical chain reaction between three element fuel, heat and oxygen (air).
Q. What is Fire Triangle/Combustion Triangle?
The fire triangle is the illustration of three essential elements of fire (Fuel, Heat and Oxygen). In absence of any one element triangle will not form i.e., fire will not occur.
Q. What are the methods for extinguishing the fire?
There are three main methods to extinguish a fire. These involves removing one of the essential elements of fire (Fuel, Heat, Oxygen):
1) Cooling – removal of Heat (by water generally for class A fire)
2) Smothering – removal of Oxygen (by using CO2 or DCP)
3) Starvation – removal of Fuel (by cutting fuel supply)
Q. What is the difference between flammable and combustible substances?
According to NFPA 30 Classification of flammable and combustible substances:
Substances which have a flash point less than 100.0 °F are called flammable — whereas fuels having a flash point above that temperature are called combustible.
Further classification:
Flammables:
Class 1A – Flash point < 73 °F, Boiling point < 100°F
Class 1B – Flash point < 73 °F, Boiling point > 100°F
Class 1C – Flash point > 73 °F < 100°F
Combustibles:
Class II – Flash point > 100 °F < 140 °F
Class IIIA – Flash point >140 <200 °F
Class IIIB – Flash point > 200 °F.
Q. What are the US and UK based classification of fire?
UK based classification of fire:
Class A – Solid fire (wood, paper, textiles etc.)
Class B – liquid fire (diesel, kerosene etc.)
Class C – Gas fire (propane, methane etc.)
Class D – Metal fire (sodium, potassium etc.)
Class F – Kitchen fire (cooking fats and oil)
Note: Previously there was a class E – Electrical fire, but later this class removed, considering electricity as a heat source.
US based classification of fire:
Class A – Solid fire
Class B – Liquefiable solid (waxes, plastics etc.), Liquid and Gas fire
Class C – Electrical fire
Class D – Metal fire
Class K – Kitchen fire.
Q. What is fire extinguisher, its types and application of each, and colour coding for different fire extinguisher?
A portable device that discharges a jet of water, foam, gas, or other material to extinguish a fire is called fire extinguisher.
Types of fire extinguishers and their application:
Water type extinguisher – Water fire extinguishers have a class A rating and are suitable for fighting fires involving solid combustibles such as wood, paper and textiles.
AFFF Foam type extinguisher – AFFF (aqueous film forming foam) foam fire extinguishers are highly effective on class A and class B fires (the foam agent helps to prevent re-ignition). Some foam extinguishers have been dielectrically tested to 35000 Volt (35kV) and can be used on or near electrical appliances.
Carbon dioxide (CO2) type extinguisher – They are ideal for electrical fires, as CO2 is not a conductor and they do not leave behind any harmful residue.
ABC Dry chemical powder type extinguisher – ABC powder fire extinguishers are extremely versatile and can be used on class A, class B, class C and electrical fires.
Water mist type extinguisher – They are highly effective on class A,B,C,F and electrical.
Wet chemical type extinguisher – Wet chemical fire extinguishers are designed specifically for use on class F kitchen fire
Colour coding for fire extinguishers:
Water type – Red
AFFF Foam – Cream
Carbon dioxide – Black
ABC Powder – Blue
Water mist – White
Wet Chemical – Yellow
Q. What is PASS method?
PASS is the acronym for Pull the safety pin, Aim nozzle at base of the fire, Squeeze the lever and Sweep side to side. This is fire extinguishing method or steps that is followed to extinguish a fire using fire extinguishers.
Q. What depth of an excavation is considered as confined space?
Practically, the excavation in an area (where oxygen deficiency or hazardous atmosphere exists or could reasonably be expected to exist) that is greater than 1.22 m in deep is considered as confined space.
Q. What is the depth of a confined space?
Depth of confined space is not defined. But generally the space that is greater than 4 feet(1.22m) in deep and meeting all other criteria of confined space, considered as confined space.
Q. What is Induction training?
Induction training is the form of introduction for new employees about the company, work activitivities, company’s health & safety policy, current hazards involved in different sites, general laws of the country if workers are from other place, emergency evacuation and fire safety etc. to enable them work safely.
Q. What is toolbox talk?
A toolbox talk is a brief informal group discussion that focuses on hazards involved in a particular job and safety precautions to be taken to minimize the risks.
toolbox talk can be organized on daily basis to promote site safety culture as well as to facilitate health and safety discussions on the job sites.
Q. What are the hazards and safety precautions for working with the electricity?
Hazards of electricity:
· Electric shock
· Fire and explosion
· Arcing
· Direct and indirect burns
· Secondary effects like fall from ladder as a consequence of electric shock
· Ultra violet radiation from arcing.
Safety precautions for electricity:
· Suitable electrical equipment should be selected for the purpose.
· Power should be isolated before working on electricity and lock-out tag-out procedure should be followed.
· Electrical works should be restricted to the competent workers only.
· All electrical installations, equipment and appliances should be subject to user checks, formal visual inspections and testing.
· Electrical equipment should not be used in wet condition.
· Various protective systems should be used such as fuses, RCB, ELCB, GFCI, earthing etc.
· Non-conductive tools to be used while working with electricity.
· Work permit system should be followed.
· Workers should wear appropriate PPEs such as electric shock proof gloves, boots etc.
Q. What are four legs of fire safety?
1. Fire protection
2. Fire prevention
3. Quantity control
4. Preventive Maintenance
Q. What is the difference between fire prevention and fire protection?
Fire prevention is about taking steps to prevent a fire from happening. For example regular inspection, provision of booths for hot work, housekeeping, properly storing materials etc.
Fire protection is the combination of different fire safety equipment and procedures that are used to control the fire and to protect the people and property. Fire protection often includes equipment like fire alarms, extinguishers and fire sprinkler system.
Q. What is CPR and process of giving CPR?
CPR (Cardiopulmonary Resuscitation) It is a life saving medical procedure which is given to someone who is in cardiac arrest. It helps to pump blood around person’s body when their heart unable to do this. It combines chest compression and artificial breathing.
Steps to follow:
Step 1- shout for help and bring the victim to the safe place.
Step 2- check for response by shaking victim’s shoulder and asking something.
Step 3- check for normal breathing by looking, listening and feeling. If the person is breathing normally then put them in recovery position and call ambulance.
If the victim is not breathing:
Step 4- ask someone to call ambulance immediately.
Step 5- Place one hand on the person’s forehead, gently tilt their head back, then lift their chin using two fingers of your other hand under their chin, this is for opening airways.
Step 6- start CPR:
· Kneel next to the person.
· Place the heel of one hand in the centre of their chest. Place your other hand on top of the first. Interlock your fingers.
· With straight arms, use the heel of your hand to push the breastbone down firmly and smoothly, so that the chest is pressed down between 5–6 cm, and release.
· Do this at a rate of 100 to 120 chest compression per minute – that’s around 2 per second.
· Give 30 chest compression.
· Open the airway again by tilting the head back and lifting the chin. Pinch the soft part of the person’s nose closed.
· Give 2 rescue breath.
· The person’s chest should rise and fall. Keeping the person’s head back and the chin lifted, take your mouth away, take another normal breath, and give a second rescue breath. The two breaths should take no longer than five seconds.
· Repeat 30 compression and two rescue breaths until ambulance arrives.
Q. What is smoke detector?
Smoke detector: A smoke detector is a device that senses smoke, typically as an indicator of fire.
Types:
Ionization smoke detector – ionisation smoke detector uses a radio isotope, typically americium-241 (an alpha emitter) to ionize air. A difference is detected in ionising process due to smoke and an alarm is generated.
Photoelectric or optical smoke detector – It contains a source of infrared, visible, or ultraviolet light (typically incandescent light bulb or LED), a lens, and a photoelectric receiver (typically a photodiode). The light emitted by the light source passes through the air being tested and reaches the photosensor. The receives light intensity will be reduced because light is scattered due to smoke particles. The circuit detects the intensity reduction and generates the alarm.
Carbon monoxide and carbon dioxide detection – fire produces carbon monoxide and carbon dioxide, and they can be detected through these detection systems. They are particularly suitable for dusty and dirty environment where ionising and optical detection systems tend to give false alarm.
Q. What is Fire Sprinkler System?
A fire sprinkler system is an active fire protection method that consists pressurised water supply through piping distribution and provides water flow through the sprinkler heads when fire is detected.
Sprinkler Head
Sprinkler head is a component of the fire sprinkler system that discharges water when fire is detected or temperature of that location exceeds the predetermined level. It has color-coded heat sensitive glass bulb filled with liquid (mixture of alcohol and water or glycerine and water) that works as a plug which prevents water from flowing. The color of the bulb indicates the activation temperature. When temperature around the sprinkler head exceeds the activation temperature, the bulb breaks and water starts flowing through the head.
Colour-code and activation temp. of bulb
Orange - 57 °C Green - 93°C
Red - 68°C Blue - 141°C
Yellow - 79°C Purple - 182°C
Q. How will you define Hazardous Waste?
The waste that is dangerous or potentially harmful to our health or the environment is known as hazardous waste.
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