Module 1: Safety Engineering of Process Plants PDF

Module 1 20CHT456 Safety Engineering of Process Plants 1 Text books for references: B. K. Bhaskara Rao, Safety in Chemical Industry/Plants and Its Management R. K. Jain & Sunil S Rao, Industrial Safety, Health and Environment Management Syste...

Module 1 20CHT456 Safety Engineering of Process Plants 1 Text books for references: B. K. Bhaskara Rao, Safety in Chemical Industry/Plants and Its Management R. K. Jain & Sunil S Rao, Industrial Safety, Health and Environment Management System 2 3  Importance of Safety It has been reported that 2,20,000 humans lose their lives & 125 millions are victims of Occupational disease and accidents in every year. 4  Safety of people in their workplaces Protecting the environment against damage from industrial accidents Protecting businesses against serious losses from damage to plant and machinery Eliminating accidents causing work stoppage and production loss. Creating awareness of the good practices available for the delivery of effective safety instrumented systems 5  Providing basic training in well-established techniques for engineering of safety systems Assisting engineers and technicians to support and participate in the safety systems activities at their work with good background knowledge of the subject Being aware of what can go wrong and how to avoid it 6  Concept of Safety To prevent of accidents by the use of appropriate technologies, to identify the hazards of a chemical plant and to eliminate them before an accident occur. The management of all operations and procedures in an industry in order to protect its employees and assets by minimizing hazards, risks, accidents, and near misses” called the Industrial Safety. 7  Important Terms Safety or loss prevention: the prevention of accidents through the use of appropriate technologies to identify the Hazard: a chemical or physical condition that hazards of a chemical plant and eliminate them before an has the potential to cause damage to people, accident occurs. property, or the environment. Incident : An event that could or does result in unintended harm to people and /or damage to property and/or environment Near-Miss (No loss type incident) Risk: a measure of human injury, Accident (loss type incident) environmental damage, or economic loss in terms of both the incident likelihood and the Danger magnitude of the loss or injury. A thing or situation which may cause ‘injury, loss, accident, etc. Such a thing or situation is ‘dangerous’, risky. 8  Basic safety rules 1. Keep work areas clean (Maintain housekeeping). Proper housekeeping alone can go a long way in preventing injuries. Injuries such as slips, trips, falls, sprains, strains, etc. can be reduced from keeping work areas organized and clean. 2. Use the proper tool for the job. Avoid the first impulse to use whatever tool is around you to get a work task done. Using the wrong tool for the job can result in an injury or damage to the tool which can lead to an injury down the road. 3. Always wear the proper PPE for the work task. The lack of PPE or the use of improper PPE leads to many injuries in the workplace. PPE is the last line of defence when protecting yourself from the hazards of your work. If you come into contact with a hazard when not wearing the correct PPE the injury will be more severe than if you were wearing it. 4. Never work on live equipment. Working on energized equipment is an unsafe act that leads to many serious injuries and fatalities every single year. Always follow proper lock out tag out procedures prior to performing any maintenance or repair work on equipment. 9 5. Make sure chemicals are properly labelled and stored. Occupational Safety and Health Administration (OHSA) issues many citations regarding the hazard communication every year. Improper labelling and storage can lead to injuries or property loss due to fires, corrosion, etc. 6. Communicate hazards to other personnel (Report Hazards). Never assume that a co-worker understands the hazards of a task especially if they are new or new to the task. When work plans or conditions change take the necessary time to inform others of the impacts the changes have on safety. 7. Stop work when needed to address hazards. Always stop work to take the time to get hazards addressed to make it safe to continue the task. Whether you need to involve other personnel such as a supervisor or you need to take time to get the right tool for the job, always take the time to do so. 10 11  Fundamental safety tenets To ensure safety of the plants, machinery and the human beings Principle 1: Responsibility for safety The prime responsibility for safety must rest with the person or organization responsible for facilities and activities that give rise to risks. Principle 2: Role of government An effective legal and governmental framework for safety, including an independent regulatory body, must be established and sustained. Principle 3: Leadership and management for safety Effective leadership and management for safety must be established and sustained in organizations concerned with, and facilities and activities that give rise to, risks. Principle 4: Justification of facilities and activities Facilities and activities that give rise to risks must yield an overall benefit. Principle 5: Optimization of protection Protection must be optimized to provide the highest level of safety that can reasonably be achieved. 12 Principle 6: Limitation of risks to individuals Measures for controlling risks must ensure that no individual bears an unacceptable risk of harm. Principle 7: Protection of present and future generations People and the environment, present and future, must be protected. Principle 8: Prevention of accidents All practical efforts must be made to prevent and mitigate accidents. Principle 9: Emergency preparedness and response Arrangements must be made for emergency preparedness and response Principle 10: Protective actions to reduce existing or unregulated risks Protective actions to reduce existing or unregulated risks must be justified and optimized. 13  Safety in the site selection & layout Plant location and site selection: The principle factors to be considered are: 1. Location, with respect to the marketing area: The location should be strategically situated within or close to the target market to reduce transportation costs, improve accessibility to customers, and enhance market penetration. 2. Raw material supply: Proximity to sources of raw materials ensures a steady and cost-effective supply chain, reducing transportation costs. 3. Transport facilities: Accessibility to transportation networks such as highways, railways, ports, and airports facilitates the movement of goods and materials, reducing transportation costs and lead times. 4. Availability of labour: The availability of skilled and unskilled labor in the vicinity affects labor costs, workforce productivity, and recruitment efforts. 5. Availability of utilities: water, fuel, power: Adequate access to essential utilities such as water, fuel, and power is critical for operations. Availability, reliability, and cost of utilities should be evaluated to ensure uninterrupted production processes. 14 6. Availability of suitable land: The availability of suitable land for construction, expansion, and future growth is essential. 7. Environmental impact, including effluent disposal: Assess the environmental impact of operations, including potential pollution, emissions, and waste generation. 8. Local community considerations: Engage with the local community to address concerns, build positive relationships, and contribute to community development. 9. Climate: Evaluate the local climate conditions, including temperature, and seasonal variations, as they can impact operations, infrastructure, and employee comfort and safety. 10. Political and strategic considerations: Consider political stability, regulatory environment, tax incentives, and government policies that may impact business operations. 15 In the past: Raw materials Transportation Marketing facility Other techno-economic factors Presently: Environmental Considerations: Environmental Impact Assessment (EIA) is a process used to evaluate the potential environmental consequences of proposed projects, policies, or activities before they are carried out. Industrial Licensing procedures (KSPCB, CPCB. etc): Industrial licensing procedures in India involve obtaining various permits and approvals from regulatory authorities such as the Kerala State Pollution Control Board (KSPCB) and the Central Pollution Control Board (CPCB) for establishing and operating industrial facilities. 16  Environmental guidelines for industries Areas to be avoided  Ecologically and or otherwise sensitive areas at least 25 km; depending on the geo- climatic conditions the requisite distance shall have to be increased by the appropriate. (Environmental conservation, Water sources, Cultural heritage sites, Disaster-prone areas)  Costal Areas: At least ½ km from high tide line. (Risk of flooding, Erosion control, Habitat preservation)  Flood plain of the river systems (Risk of flooding, Property damage, Environmental impact)  Transport/ communication system  Consider direction of growth 17  Siting Criteria ( Mandatory)  No forest land shall be converted into non-forest activity (Ref: Forest Conservation Act 1980).  No prime agricultural land shall be converted into industrial site.  Land acquired shall sufficiently large to provide space for waste water treatment , reuse and solid waste management.  There should be a green belt of about ½ km wide around the battery limit of the industry.  For industry having odor problems the green belt shall be a kilometer wide.  The green belt between two adjoining large scale industries shall be 1 km.  Should maintain three ambient air quality measuring stations within 120o angle between stations. 18  Safety in Plant Layout Storage and handling facilities for explosive and flammable substances as raw material, intermediate product and finished product stages Electrical equipment, wiring and installation, lighting, power supply including emergency stand by power Handling equipment such as winches, pulleys, cranes, lifts, conveyors etc. Boilers and other pressure equipment Ventilation, heating, air conditioning Fire protection Waste and effluent disposal First aid, medical facilities, personal protection equipment, noise and sanitation 19  Critical Factors to be considered in Plant layout Segregation of hazardous process areas Provision of a separate area for storage of flammable and hazardous materials Provision of a separate location for furnaces, heaters etc. Using flame at a safe distance from areas where flammable and volatile materials are handled. Location of control room /Protection Fire water tank and fire water pump house Congestion in the plant site because of buildings, structures, pipelines, trees etc. The emergency exit gate shall be away from the main gate and always be available for use for personnel evacuation during emergency. Evacuation routes should not be blocked by poor plant layout 20  Accidents An unpleasant , unexpected, unforeseen or unintended happening sometimes resulting from negligence, that results in injury, loss, damages, etc. and is caused by a mistake or machine failure or natural disaster, or sabotage. Accidents may lead to Injury or even death of a worker. Accidents may occur due to Damage to the plant and the equipment 1. Human error (unsafe practices) – 88% Disruption of production schedules 2. Mechanical failure (plant condition, equipment failure) – 10% Prolonged absence of trained worker for treatment 3. Acts of nature (poor weather, flood, cyclone) – 2% It indicates that 98% of accidents can be prevented. 21  Classification of Accidents Fires and Explosions (Accidents involving the ignition and combustion of materials resulting in fires or explosions, which can cause damage to property, injuries, or fatalities) Electrical Accidents (often occurring due to faulty wiring, equipment malfunction, or human error) Shocks and Flashovers Fires and Explosion initiated by Sparks and Short-circuit currents Failures and accidents in electrical plants. Chemical accidents and Explosions (Events involving the release, spillage, or mishandling of hazardous chemicals, leading to explosions, fires, toxic exposures, or environmental contamination) Emission of gases, Fumes, Dust , Chemical Fluids Nuclear disasters, Radiation of radioactive materials Accidents with machines, Plant, Tools (Incidents involving machinery, equipment, or tools, including malfunctions, mechanical failures, or accidents during operation, maintenance, or repair activities) Human error Failure of plant accessory Process hazard (eye injury due to LASER, welding lights) 22  Falling of Objects on body (Accidents where objects or materials fall onto individuals, potentially causing injuries such as bruises, cuts, or fractures) Due to construction work Due to operation of the plant Falling of persons in pits or height Accidents from civil works During construction Service life of plant (Accidents or incidents related to the operational lifespan of industrial plants or equipment, including wear and tear, degradation, or structural failures over time) Human made accidents Sabotage Theft Natural disasters 23 Causes of accidents 24 Unsafe Act: An unsafe act refers to any action or behaviour performed by an individual in the workplace that deviates from established safety procedures, policies, or standards, thereby increasing the risk of accidents or injuries. Example:  Failing to wear personal protective equipment (PPE) when required.  Disregarding safety protocols or procedures. 25 Unsafe Condition: An unsafe condition refers to any situation, circumstance, or environmental factor in the workplace that poses a hazard or increases the likelihood of accidents or injuries. Unsafe conditions can result from equipment malfunctions, poor maintenance practices, inadequate safety measures, or environmental factors. Example:  Slippery floors or walkways due to spills or inadequate cleaning.  Overcrowded or cluttered work areas that impede movement or access to emergency exits.  Defective or malfunctioning equipment, machinery, or tools. 26 27 28  Cost of industrial accidents  Direct Costs Loss of Life  Payment of compensation to the accident victims Permanent Disability and  Medical expenses incurred by the management for the injured in the Distress accident Lost Production  Indirect Costs Damaged Materials  Cost involved in the enquiry and preparation of investigation Medical Cost reports on accidents  Cost of time lost by other personnel than those involved in the Insurance, Compensation etc. accident.  Cost involved in recovery and salvage of damaged equipment and cleaning the accident area.  Loss of prestige and public confidence  Degradation of morale among workers 29 30 Key safe practices in chemical industry for accident prevention programme 1. House-keeping  Effective housekeeping can help control or eliminate workplace hazards.  Poor housekeeping practices frequently contribute to incidents.  Housekeeping is not just cleanliness.  It includes keeping work areas neat and orderly, maintaining halls and floors free of slip and trip hazards, and removing of waste materials (e.g., paper, cardboard) and other fire hazards from work areas.  It also requires paying attention to important details such as the layout of the whole workplace, aisle marking, the adequacy of storage facilities, and maintenance.  Good housekeeping is also a basic part of incident and fire prevention. 31 Purpose of workplace housekeeping Poor housekeeping can be a cause of incidents, such as: Tripping over loose objects on floors, stairs and platforms Being hit by falling objects Slipping on greasy, wet or dirty surfaces Striking against projecting, poorly stacked items or misplaced material Cutting, puncturing, or tearing the skin of hands or other parts of the body on projecting nails, wire or steel strapping. To avoid these hazards, a workplace must "maintain" order throughout a workday. Although this effort requires a great deal of management and planning, the benefits are many. 32  2. Work Place Safety Self and others safety is primary responsibility of each employee (use helmets and safety shoes at work). Good work culture and attitude Make proper work plan.  Identify various activities required for the job.  Determine the specific tasks and responsibilities involved in the job.  Understand the sequence of activities required to complete the job efficiently and safely.  Communicate with supervisors or engineers in charge to clarify any uncertainties regarding job duties.  Find out the likely hazards and plan for remedial measures.  Conduct a thorough risk assessment to identify potential hazards associated with each task.  Determine appropriate control measures to mitigate or eliminate identified hazards.  Develop a comprehensive safety plan outlining procedures and protocols to address potential risks.  Provide training to employees on hazard recognition and proper safety procedures. 33  Appropriate safety apparels for work.  Assess the specific hazards present in the work environment.  Choose safety apparel suitable for protecting against identified hazards (e.g., hard hats, safety glasses, gloves,  steel-toed boots).  Ensure safety apparel is properly fitted and in good condition to provide adequate protection.  Check/Inspect the tools for usage.  Regularly inspect tools and equipment to ensure they are in good working condition.  Check for signs of damage, wear, or malfunction that could pose a safety hazard.  Perform routine maintenance and repairs as needed to keep tools functioning properly.  Provide proper training on the safe operation and maintenance of tools to employees. 34  Discuss the work plan with engineer in charge /supervisor.  Collaborate with the engineer in charge or supervisor to develop a detailed work plan.  Communicate expectations, timelines, and safety considerations for the job.  Address any concerns or questions regarding the work plan and make necessary adjustments as needed.  Ensure all team members are aware of their roles and responsibilities.  Place of work should be stable and possible risks should be avoided.  Evaluate the stability of the work area and address any potential hazards (e.g., unstable surfaces, overhead hazards, confined spaces).  Implement measures to prevent slips, trips, and falls, such as maintaining clean and clutter-free workspaces.  Secure tools, materials, and equipment to prevent them from falling or shifting during work activities.  Monitor environmental conditions (e.g., weather, lighting) that could impact safety and take appropriate precautions. 35  Safe Working Environment  Illumination  Proper artificial lighting should be provided as per IS : 3646 (part II)  No glaring lights: Avoid glaring lights that can cause discomfort or reduce visibility, especially in areas where employees perform tasks requiring focused attention.  Windows providing natural lighting should be cleared regularly outside and inside  Speak with supervisor on noting any malfunctions  Noise Pollution  < 85 dBA and should not exceed 90 dBA Prevention of noise pollution  Proper maintenance and lubrication: Implement measures to prevent noise pollution, including regular maintenance and lubrication of machinery and equipment to reduce noise emissions.  Provide ear plug for workers (Regular audiometry check ): Provide personal protective equipment (PPE) such as earplugs or earmuffs to workers exposed to high noise levels. Conduct regular audiometry checks to monitor workers' hearing health and detect any signs of noise-induced hearing loss.  Install silencers/acoustic linings and mufflers 36  Safe Working Environment  Dust/Fumes/Gas  Thermal radiation No person is allowed to enter any chamber/tank or pipe or  Proper maintenance of thermal shields other confined place where gas /vapor/fumes are likely present,  Minimum exposure to melting and hot parts unless:  Appropriate protections for workers  Manhole or Access Point: Manhole of adequate size is  Waste Disposal provided  No burying of waste  Work Permit: Work permit from competent authority of  Appropriate waste disposal measures safety of the work environment.  Proper handling of toxic chemicals  Containment: Harmful substances should be confined to  Proper clearing of pipes and drains regularly airtight apparatus.  Proper sewage treatment facilities  Ventilation: Proper ventilation and temperature control  Meet norms and standards of disposal  Washing Facilities: Adequate washing facilities and supply  Permission to transport waste off site of good water supply. 37   Maintain Light Fixtures Dirty light fixtures reduce essential light levels. Clean light fixtures can improve lighting efficiency significantly.  Aisles and Stairways Wide enough to accommodate people and vehicles comfortably and safely. Warning signs and mirrors can improve sight-lines in blind corners Keeping aisles and stairways clear is important. Should not be used for temporary "overflow" or "bottleneck" storage. Adequate lighting. Stop them before they happen  Spill Control Important to clean them up immediately. Absorbent materials are useful for wiping up greasy, oily or other liquid spills. Used absorbents must be disposed of properly and safely. 38  Assignment 1 Write a short review about the major Chemical industry accidents: {Contents : Major Causes, Effects, action taken } 1. Bhopal Tragedy 2. Flix borough 3. Seveso disaster 39  Material safety data sheet A material safety data sheet is a technical document which provides detailed and comprehensive information on a controlled product related to:  Health effects of exposure to the product  Hazard evaluation related to the product’s handling, storage or use  Measure to protect workers at risk of exposure  Emergency procedures. Safety Data Sheets (SDSs) (formerly MSDSs or Material Safety Data Sheets) Data sheet may be written, printed or otherwise expressed, and must meet the availability, design and content requirements of WHMIS (Workplace Hazardous Materials Information System) legislation. The SDS includes information such as the properties of each chemical; the physical, health, and environmental health hazards; protective measures; and safety precautions for handling, storing, and transporting the chemical. The information contained in the SDS must be in English (although it may be in other languages as well). 40 41 42 43 44 45 46 47 48 49 50 51  Boiling point: Temperature at which liquid changes to vapor state.  Melting point: Temperature at which solid begins to changes to liquid.  Vapor pressure: Measure of how volatile a substance is and how quickly it evaporates.  Vapor density (air =1): Weight of a gas or vapor compared to weight of an equal volume of air.  Specific gravity (water=1): Ratio of volume weight of material to equal volume weight of water.  Solubility in water: Percentage of material that will dissolve in water, usually at ambient temperature. 52 53 54 55 56 57 58  Work permit system A work permit is a written record issued by the authorized personal permitting a specific task for a specified time frame and defined area. OBJECTIVES  To Provide Safe working conditions  To exercise control over the maintenance, repair and construction activities by assigning responsibilities.  To serve as an official written record of conditions and requirement for safe execution of work.  To allow and authorize the work to be carried out.  To fix the responsibility of each party for the safe execution of work.  To serve as a general guide and to ensure adequate preparation has been taken to make the job safe.  Safe hand over from operation to maintenance. 59  Work permit system Content included in a work permit system  The description of the work to be performed  The location of the work area  Permit receiver and permit issuer  List of person(s) performing work  Identify hazards and precautions  Identify any extra permits that may be required  List of check and review points  Emergency procedure and contact  Time limit of the work Jobs where a Permit is required include:  Excavation  Maintenance Work  Vehicle/Mobile Equipment Entry into Hazardous Areas  Construction and Project Work  Other Activities Serving the refinery operations  Alterations / Modifications  Non – routine work in workshops, warehouse, etc.  Process Equipment Cleaning Activities  For all non routine jobs which are not covered by operating  Inspection and Condition Monitoring procedures, mainly maintenance or repair works  Entry into Confined Space 60  Work Permit System WORK NOT REQUIRING A PERMIT:  Routine work carried in established workshops and adjacent yards with fixed boundaries.  Routine material handling work in established warehouses and adjacent lay down yards with fixed boundaries.  Routine office work including cleaning, servicing of office equipment, communication equipment in buildings etc.  Maintenance cold work in building outside hazardous area (other than control rooms) which does not exceed climbing of ladder or scaffold over 2 meters.  Eg: Hand tool work, revamping, servicing of air conditioners, painting etc.  Visual inspection in operational areas excluding confined spaces with the verbal permission of the custodian.  Work carried out by Operations Dept. personnel as part of their routine Operations, start-up and shutdown.  Work carried out in areas designated as ‘permit free’ by written approval from Supdt., Safety. 61  Principles of work permit  JOB PLANNING  JOB PREPARATION  AUTHORIZATION  SUPERVISION  VALIDITY & EXTENSION  HAND BACK 62  Work permit system JOB PLANNING JOINTLY BY ISSUER & JOB PREPARATION BY OPERATION ACCEPTER  Decontamination By Draining, Purging, Cleaning.  Job scope  Equipment details - a common procedure used to remove contaminants from  Requirement of tools, tackles or lifting machine various systems, equipment, or environments  Risk & hazard analysis  Isolation- Physical By Valves (Single/Double),  Requirement of personal protective equipment Disconnection.  Trained personnel  Isolation- Energy By Electrical Fuse Removal, Tagging  Communication with all concerned And Lock Out Mechanical, Steam Or Pneumatic Isolation, Cathodic Protection Or Radioactive Source.  Access Or Approach - Ladder, Platform ,Gas Test.  Communication of Residual Hazards & PPE to be Used. 63  AUTHORIZATION VALIDITY & EXTENSION o Issue by operation or owner of the area o End of the shift or as specified in permit o Sr. Engr., Engr., Supervisor, foreman o Extension after each expiry of validity / shift o Acceptance by concerned maintenance mechanical, electrical, civil change o Sr. Engr., Engr., Supervisor, foreman o Extension for maximum two times o Electrical for isolation o Electrical engr., Foreman o Safety HAND BACK o Sr. Supervisor, engr., Supervisor, inspector o Maintenance has to certify that work is finished (completion of job) SUPERVISION o Housekeeping of the area / equipment o By maintenance foreman / group leader o Restoration of energy o By operation or area owner supervisor o Restoration of physical isolation o By area operator / filling station foreman o Remove barricading / road closure o Safety inspector / safety engineer o Cancellation of permit o By supdt. / Manager o Recording of actual work done 64  Work permit system TYPES OF WORK PERMIT o HOT WORK / VEHICLE ENTRY PERMIT o Red permit o Authorization to perform tasks in conditions that produce sparks, flames or any source of ignition. o Eg: Welding, Flammable gases and other heat inducing operation o COLD WORK PERMIT o Green permit o Authorization to operate machinery or other functions that do not generate any form of heat in the manufacturing process. o Eg: Mechanically induced bending, shearing, squeezing and drawing etc. o CONFINED SPACE ENTRY PERMIT o Yellow form o Authorization to perform task in a narrow space which is prone to hazards like asphyxiation, a substance that has ability to engulf, toxic atmosphere etc. o Eg: Vents, sewages, tanks 65  Work permit system Types of work permit o EXCAVATION AUTHORIZATION o White form o Authorization for personnel to mine or dig land in order to build infrastructure, extract resources or unearth hidden artifacts. o The risk involved in excavation includes falling, being trapped, explosions, airborne contaminants etc. o HIGHT WORK PERMIT o Authorization to work on elevated space (2 m from ground), be it ladders, scaffolds, Mobile Elevated Work Platform (MEWP) or spaces that are off the ground. o ELECTRICAL ISOLATION PERMIT o Authorization to work in high voltage zones that are prone to uncontrolled dispersion of electricity. o CHEMICAL WORK PERMIT o Authorization to work with harmful chemical substances or in a chemical induced atmosphere that is either toxic or corrosive in nature. 66  Work permit system PRECAUTIONS FOR COLD WORK PRECAUTIONS FOR HOT WORK o Follow safe maintenance procedure and work permit o All precautions mentioned in cold work procedure o Keep all combustible away from hot work o Use proper tools o Contain sparks at source o Use proper PPE-helmet, boots, hand gloves, goggles or o Keep fire extinguisher and fire hose ready specific required PPE o Keep welding or cutting set at safe distance o Use proper scaffold or ladder or platform for approach o Periodic gas test o Use proper lifting machine o Fire watch if required o Barricade area if required 67  Work permit system  Confined Space o A “confined space” is any chamber, tank, manhole, vat, silo, pit, pipe, flue or any other enclosed space, o In which: o Dangerous gases, vapors or fumes are liable to be present to such an extent as to involve risk of fire or explosion. o The supply of air is inadequate, o or is likely to be reduced to be inadequate, for sustaining life; o or there is a risk of engulfment by material. PRECAUTIONS FOR CONFINED SPACE ENTRY PERMIT o All precautions mentioned in cold work o Ensure adequate ventilation & illumination (24v DC) o Provide communication system o Ensure ELCB (Earth leakage circuit breaker) is used for o Prepare rescue plan and keep rescue stand by portable power tools o Periodic / continuous gas test o Come out if you feel uncomfortable 68  Why working in confined spaces is hazardous? Working in confined spaces is more hazardous than working in other workplaces because: o The entrances/exits of confined spaces might not allow the entrant to evacuate effectively o Flood or collapse of free-flowing material; o Self-rescue by entrant is more difficult; o Rescue of the victim is more difficult. o The interior configuration of a confined space often restricts the movement of people or equipment within it; o Natural ventilation alone is often not sufficient to maintain breathable quality air because the interior configuration of some confined spaces does not allow air movement to circulate; o Conditions can change very quickly; o Work activities may introduce hazards not present initially. 69  Work permit system PRECAUTIONS FOR EXCAVATION WORK o All precautions mentioned in cold work o Use manual tool before using power tool o Barricade area or road closure o Provide shoring o Provide warning signs & lights o Provide proper access o Keep excavated soil away from edge o Provide fire extinguisher 70  Personal protective equipment's (PPE’s) Personal protective equipment (PPE) can protect you against chemical and physical hazard exposure. List of PPE’s: o Safety helmet o Chemical resistant/ Safety shoes o Boiler suit /chemical resistant suit o Goggles o Solvent gloves o Face mask and face shield (if necessary) o Ear buds o Hydrocarbon detectors o H2S detectors o Fire detecting alarms o Air respirator (if necessary) 71 Personal protective equipment's (PPE’s) 72 Personal protective equipment's (PPE’s) 73