IS 103 SAFETY ENGINEERING – II SBTET AP IS

3.1 AGRO INDUSTRY / SUGAR INDUSTRY

3.1.1 Agro Industry Overview

• Agro-based industries include food processing, sugar, cotton, jute, rice mills, oil extraction, etc.

• Major hazards arise due to machinery, dust, fire, explosion, and ergonomic strain.

• Seasonal operations and temporary labor increase accident risks.

3.1.2 Safety in Harvesting and Post-Harvest Activities

Activities Involved:

• Cleaning, trimming, grading, drying, decorticating, retting, cooling, and bulk packaging.

• Cotton picking, threshing, milling, bagging, and storage.

Typical Hazards:

1. Machinery Hazards – moving parts of threshers, crushers, conveyors.

2. Dust Explosions – grain or sugar dust can ignite when suspended in air.

3. Ergonomic Hazards – repetitive movements, manual lifting, awkward posture.

4. Chemical Exposure – fertilizers, pesticides, fumigants.

5. Fire and Explosion – due to combustible materials like husk, bagasse, and dust.

6. Heat Stress – common during summer harvesting operations.

Preventive Measures:

• Proper guarding of rotating parts.

• Regular cleaning to prevent dust accumulation.

• Safe electrical wiring and earthing in dusty areas.

• Adequate ventilation and temperature control.

• Use of PPE: gloves, dust masks, goggles, and safety shoes.

• Fire extinguishers and sand buckets near storage areas.

• Training workers on safe handling of tools and equipment.

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3.2 METAL INDUSTRY (FERROUS AND NON-FERROUS)

3.2.1 Manufacture of Basic Metals

• Ferrous metals: Iron and Steel.

• Non-Ferrous metals: Aluminum, Copper, Zinc, Lead, etc.

• Processes Involved: Smelting, refining, casting, rolling, forging, machining.

Major Hazards:

• High temperature, molten metal splash, burns.

• Explosion due to water contact with molten metal.

• Fumes, gases, and dust exposure (silica, manganese, lead).

• Fire hazards due to oil or grease near hot surfaces.

• Noise and vibration from heavy machinery.

Control Measures:

• Use of heat-resistant clothing, gloves, face shields.

• Maintain dry working floors to prevent molten metal explosions.

• Provide fume extraction and exhaust systems.

• Use flameproof electrical fittings in furnace areas.

• Install guard rails and barriers near hot zones.

• Routine health check-ups for respiratory and hearing protection.

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3.2.2 Metallurgy – Foundry and Steel Plants

Foundry Operations: Melting → Molding → Casting → Fettling → Machining.
Steel Plants: Raw material handling → Coke oven → Blast furnace → Steel making → Rolling.

Hazards:

• Burns and heat stress.

• Metal splash and hot slag.

• Dust and gas inhalation (CO, SO₂, silica).

• Noise and vibration during rolling operations.

• Electrical and mechanical hazards during material handling.

Safety Measures:

• Local exhaust ventilation (LEV) near furnaces.

• Regular inspection of lifting gear and cranes.

• Proper refractory maintenance in furnaces.

• Adequate illumination and warning systems.

• Implementation of confined space entry procedures in tanks/pits.

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3.2.3 Hazards in Melting, Casting, Forging, Rolling, and Testing

Melting Hazards:

• Furnace explosion due to wet scrap.

• Fire from leaking fuel or oxygen lines.

• Burns from molten splash.
  Controls:

  • Preheat and dry charge materials.

  • Maintain proper fuel-air ratio.

  • Isolate fuel supply in emergencies.

Casting Hazards:

• Metal spillage and hot metal contact.

• Sand mold explosion (moisture).
  Controls:

  • Use dry sand molds.

  • Provide PPE and safe pouring distance.

Forging Hazards:

• Hammer and press accidents.

• Flying metal pieces and noise.
  Controls:

  • Guard hammer mechanisms.

  • Provide ear protection and safety screens.

Rolling Hazards:

• Entanglement between rolls.

• Heat and noise exposure.
  Controls:

  • Install nip guards.

  • Maintain emergency stop systems.

Non-Destructive Testing (NDT):

• Hazards due to radiography (X-rays, gamma rays).

• Control: Follow BARC/AECL radiation safety norms, use dosimeters, and shielding.

Pollution Control Measures:

• Install dust collectors, wet scrubbers, and filters.

• Proper waste disposal of slag and metal scrap.

• Maintain air quality per CPCB and EPA norms.

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3.3 AUTOMOBILE MANUFACTURING INDUSTRY

3.3.1 Major Activities

• Pattern making, molding, melting, machining, forging, chipping, grinding, heat treatment, and NDT.

Hazards:

1. Machinery Hazards: Entanglement, crushing, cutting.

2. Fire and Explosion: Flammable liquids and gases in paint shops or fuel testing.

3. Ergonomic Hazards: Repetitive operations, awkward posture.

4. Chemical Exposure: Paints, solvents, lubricants.

5. Noise and Vibration: Grinding, forging, stamping operations.

6. Heat Hazards: From furnaces and heat treatment equipment.

Pollution Control Measures:

• Install effluent treatment plants (ETP) for process waste.

• Provide fume extraction in welding and painting areas.

• Use noise control enclosures around heavy machines.

• Ensure proper ventilation and dust suppression.

• Regular environmental monitoring and waste segregation.

General Safety Precautions:

• Machine guarding and emergency stop controls.

• Safe storage of chemicals and flammable materials.

• Preventive maintenance and inspection schedule.

• Worker training on PPE use and safe machine operation.

• Display of safety signage and evacuation routes.

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3.4 TEXTILE INDUSTRY

3.4.1 Introduction

• Textile industry includes processing of natural fibers (cotton, jute, silk, wool) and synthetic/man-made fibers (nylon, polyester, rayon, acrylic, etc.).

• Main processes:

  1. Fiber preparation – cleaning, carding, combing.

  2. Spinning – conversion of fibers to yarn.

  3. Weaving/Knitting – yarn to fabric.

  4. Dyeing and Printing – coloring and finishing.

  5. Finishing – drying, pressing, packaging.

Significant Hazards

1. Mechanical Hazards:

   • Entanglement in rotating parts (spindles, rollers, conveyors).

   • Nip points in looms and carding machines.

   • Flying fibers causing eye injury.

2. Fire and Explosion Hazards:

   • Cotton and jute dust are highly combustible.

   • Flammable solvents and dyes in printing sections.

   • Static electricity accumulation.

3. Dust and Health Hazards:

   • Inhalation of cotton dust causes Byssinosis (lung disease).

   • Continuous noise exposure causes hearing loss.

   • Skin irritation from dyes and chemicals.

4. Chemical Hazards:

   • Exposure to acids, alkalis, bleaches, solvents, and dyes.

   • Toxic fumes during synthetic fiber processing.

5. Ergonomic Hazards:

   • Repetitive operations, prolonged standing, awkward posture.

Preventive Measures

• Machine guarding and emergency stop buttons.

• Proper housekeeping to avoid fiber accumulation.

• Use of humidifiers to reduce static build-up.

• Adequate ventilation and dust extraction system.

• Fire protection system: smoke detectors, extinguishers, hydrants.

• Safe storage of dyes and flammable chemicals.

• Use of PPE: masks, gloves, ear protection.

• Regular medical check-ups and health surveillance.

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3.5 CONSTRUCTION INDUSTRY

3.5.1 Basic Philosophy and Parameters

• Construction industry is dynamic, temporary, and high-risk, involving multiple agencies and frequent site changes.

• Safety depends on planning, supervision, and worker discipline.

Key Safety Considerations

1. Site Planning and Layout:

   • Proper fencing, access roads, safe zones, and material storage.

   • Segregation of pedestrian and vehicle routes.

   • Availability of first-aid and fire-fighting facilities.

2. Safe Access and Egress:

   • Provide ladders, scaffolds, walkways with guardrails.

   • Maintain proper illumination and signage.

3. Good Housekeeping:

   • Clear debris regularly.

   • Designate safe storage areas for tools and materials.

   • Prevent slips, trips, and falls.

4. Safety in Construction Machinery:

   • Cranes, hoists, concrete mixers, and vehicles should be inspected regularly.

   • Operators must be trained and certified.

   • Provide reverse alarms and barricading around operating areas.

5. Signs and Indications:

   • Use standard color codes (IS 2379) for identification of hazards.

   • Display safety signs, warnings, and emergency contacts.

6. Liaison with Local Authorities:

   • Coordinate with municipal, electrical, and fire departments for compliance.

7. Structural Soundness:

   • Ensure design safety and stability before load application.

   • Test scaffolding, formwork, and temporary structures.

Accidents and Hazards

• Common causes: falls from height, electrocution, struck by objects, collapse of structure, excavation cave-ins.

• Effects: injuries, fatalities, project delays, financial losses.

Preventive Measures

• Conduct Job Safety Analysis (JSA) before each activity.

• Compulsory use of helmets, harness, gloves, and boots.

• Regular safety inspections and toolbox talks.

• Implement Permit-to-Work system for high-risk jobs (confined space, hot work, etc.).

• Emergency preparedness and rescue plan on site.

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3.6 IT AND ELECTRONICS INDUSTRY

3.6.1 Manufacture of Computers, Radios, TVs, and Communication Equipment

• Includes production of microprocessors, circuit boards, displays, wiring harnesses, and assembling of electronic devices.

• Involves soldering, testing, assembly, and packaging operations.

Hazards:

• Exposure to lead, solder fumes, fluxes.

• Electrical shock and static discharge.

• Fire from short circuits or overheating.

• Eye strain from continuous display screen exposure.

• Ergonomic strain due to repetitive hand movement.

Preventive Measures:

• Use of lead-free soldering materials.

• Install local exhaust ventilation (LEV) for soldering fumes.

• Regular inspection of electrical connections.

• Use anti-static wrist straps and mats.

• Provide ergonomic furniture and adequate lighting.

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3.6.2 Manufacture of Electronic Valves, Tubes, and Electro-Magnetic Devices

• Involves use of high voltage, vacuum systems, chemicals, and magnetic fields.

Hazards:

• Glass breakage and cuts.

• Burns from vacuum tube sealing.

• High voltage electric shock.

• Exposure to barium, lead, and mercury.

Preventive Measures:

• Shielding for high-voltage circuits.

• Use of gloves and protective eyewear.

• Proper ventilation and fume extraction.

• Safe waste disposal for heavy metals.

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3.6.3 Safety in Semiconductor Industry

• Semiconductor fabrication involves photolithography, etching, doping, diffusion, and wafer processing.

Hazards:

1. Chemical Hazards: Hydrofluoric acid, solvents, silane gas (toxic & flammable).

2. Physical Hazards: UV and laser radiation, clean room pressure changes.

3. Ergonomic Hazards: Repetitive work, long standing hours.

Preventive Measures:

• Use fully enclosed systems for chemical transfer.

• Provide gas detection and exhaust systems.

• Maintain clean room discipline and PPE (hood, gloves, face shield).

• Emergency eye wash and shower facilities.

• Training in chemical spill and fire response.

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3.7 SAFETY IN DOCKS

3.7.1 Safety in Docks – Overview

• Dock work includes loading, unloading, stacking, and movement of cargo at ports and harbors.

• It involves ships, cranes, forklifts, conveyors, and manual handling, creating multiple hazards.

• Governed by Dock Workers (Safety, Health and Welfare) Regulations, 1990 under the Dock Workers Act, 1986.

3.7.2 Handling of Cargo

Types of Cargo:

• General cargo (bags, boxes, timber, steel).

• Bulk cargo (coal, cement, grains).

• Liquid cargo (petroleum, chemicals).

• Hazardous cargo (flammables, corrosives, explosives).

Major Hazards:

• Falling objects, shifting of loads.

• Slips and trips on uneven surfaces.

• Crane or sling failure.

• Exposure to dust, fumes, or toxic vapors.

• Fire and explosion risks with flammable materials.

Preventive Measures:

• Use proper lifting tackles, tested and certified as per IS standards.

• Maintain clear walkways and lighting.

• Use correct Personal Protective Equipment (PPE) – helmet, gloves, safety shoes, life jacket.

• Proper stacking and segregation of cargo.

• Continuous supervision during loading/unloading.

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3.7.3 Container Operations

• Use of container cranes, forklifts, reach stackers for lifting and stacking containers.

• Containers may contain hazardous materials, requiring special handling.

Safety Measures:

• Inspect containers for damage or leaks before movement.

• Ensure proper twist-locking of containers on trailers.

• Follow safe stacking height limits.

• Maintain safe zones and signal systems during crane operation.

• Operators must be trained and certified.

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3.7.4 Lifting Appliances

• Includes cranes, winches, derricks, forklifts, hoists, and slings.

Safety Requirements:

• All lifting appliances to be tested and certified periodically by a competent person.

• SWL (Safe Working Load) must be clearly marked.

• Use proper slings and shackles of rated capacity.

• Ensure stability and balance of load before lifting.

• Avoid overloading or sudden jerks.

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3.7.5 Responsibilities of Different Agencies

1. Port Trust/Management:

   • Maintain dock safety rules and infrastructure.

   • Provide training, emergency response, and fire protection.

2. Stevedores/Contractors:

   • Ensure safety of their workers.

   • Maintain lifting appliances and tools.

3. Shipping Company:

   • Provide safe access to vessel, ensure cargo stability.

4. Dock Workers:

   • Follow safety instructions and wear PPE.

   • Report unsafe conditions.

5. Government Authorities:

   • Enforce compliance through inspections and audits.

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3.8 SAFETY IN BOILERS

3.8.1 Boiler Safety – Introduction

• Boiler: Closed vessel where water is heated to produce steam under pressure.

• Used in power plants, refineries, textile, food, and chemical industries.

• Governed by the Indian Boilers Act, 1923 and Boiler Regulations, 1950.

3.8.2 Safety Precautions and Operation

Major Hazards:

• Explosion due to overpressure or low water level.

• Tube failure, overheating, and fire.

• Chemical burns from steam or hot water.

Precautions:

• Operate within design pressure and temperature limits.

• Ensure safety valves, pressure gauges, and water level indicators are working.

• Use soft feed water to prevent scaling.

• Provide blowdown valve for sludge removal.

• Conduct regular inspection and hydro testing.

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3.8.3 Types of Boilers & Hazards

• Fire Tube Boiler: Hot gases pass through tubes (e.g., Cochran, Lancashire).

• Water Tube Boiler: Water flows inside tubes (e.g., Babcock & Wilcox).

• Hazards: pressure failure, tube rupture, blowback.

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3.8.4 Preservation of Boilers (When Not in Use)

Methods:

1. Dry Preservation:

   • Remove water completely, dry internal surfaces, and fill with desiccant (silica gel).

2. Wet Preservation:

   • Fill with treated water and add sodium nitrite or hydrazine to prevent corrosion.

3. Mechanical Protection:

   • Close all openings, lubricate moving parts, and cover externally.

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3.8.5 Steam Pressure and Gauges

• Steam Pressure Gauge: Indicates operating pressure of the boiler.

• Must be tested and calibrated regularly.

• Safety Valve: Automatically releases steam when pressure exceeds safe limit.

• Pressure Limits: Maintain below design pressure as per manufacturer’s specification.

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3.8.6 Treatment of Feed Water

• Purpose: To prevent scaling, corrosion, and carryover.

• Treatment Methods:

  • External Treatment: Filtration, softening, demineralization.

  • Internal Treatment: Use of chemicals like phosphate and hydrazine.

• Maintain pH between 8.5 – 9.5 for feed water.

• Periodic blowdown to control solids concentration.

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3.9 ENVIRONMENTAL PROTECTION

3.9.1 Introduction

• Environmental protection is essential to maintain ecological balance and comply with legal requirements.

• Controlled by acts like Environment (Protection) Act, 1986, Air Act, 1981, Water Act, 1974, and Hazardous Waste Rules, 2016.

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3.9.2 Principles and Practices for Pollution Control

A. Air Pollution

Sources:

• Emissions from boilers, furnaces, vehicles, DG sets, chemical processes.
  Control Measures:

• Use of filters, scrubbers, electrostatic precipitators (ESP).

• Conversion to cleaner fuels (CNG, LPG, biofuel).

• Green belt development and stack emission monitoring.

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B. Water Pollution

Sources:

• Industrial effluents, cooling water, domestic sewage.
  Control Measures:

• Effluent Treatment Plant (ETP) installation.

• Segregation of process and storm water drains.

• Reuse and recycling of treated water.

• Maintain discharge standards as per CPCB norms.

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C. Solid and Hazardous Waste Management

Principles:

• Follow Reduce–Reuse–Recycle (3R) approach.

• Identify hazardous wastes (e.g., oils, solvents, heavy metal sludge).
  Control Measures:

• Proper labeling, storage, and transport under Hazardous Waste Management Rules, 2016.

• Secure landfill or incineration of toxic waste.

• Maintain waste records and manifest system.

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3.10 WORK PERMITS

3.10.1 Work Permits – Application, Adoption and Enforcement

Definition

A Work Permit is a written authorization that specifies the type of work, hazards involved, and precautions to be taken before starting potentially hazardous jobs.

It ensures control, communication, and coordination among all personnel involved.

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Purpose of Work Permit

• To prevent accidents by controlling high-risk activities.

• To identify hazards and specify safety precautions before starting work.

• To ensure supervision, isolation, and safe restoration of the area after work.

• To provide a record of authorization and accountability.

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When Work Permits Are Required

• Hot work (welding, gas cutting, grinding).

• Confined space entry (tanks, pits, manholes).

• Electrical isolation and maintenance.

• Excavation and trenching.

• Working at height.

• Radiography or radioactive material use.

• Line breaking or pressure system work.

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Types of Work Permits

1. Hot Work Permit – For any job generating flame, spark, or heat.

2. Cold Work Permit – For maintenance without ignition sources.

3. Confined Space Entry Permit – For entry into limited spaces with restricted ventilation.

4. Electrical Work Permit – For electrical isolation, testing, or maintenance.

5. Height Work Permit – For jobs above 2 meters.

6. Excavation Permit – For digging or trenching near utilities.

7. Radiography Permit – For work involving radiation sources.

8. Vehicle Entry Permit – For vehicles entering hazardous process areas.

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Key Elements of a Work Permit

• Job description and location.

• Date, time, and duration.

• Identification of hazards.

• List of safety precautions and PPE.

• Isolation and gas testing requirements.

• Authorized signatures (Issuer and Receiver).

• Permit validity and cancellation section.

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Procedure for Permit System

1. Application:

   • The job supervisor applies for a permit describing work and hazards.

2. Assessment:

   • Safety officer/authorized person inspects site, verifies isolation, and recommends precautions.

3. Issuance:

   • Permit issued by competent authority with signatures.

4. Display:

   • Copy displayed at work site until job completion.

5. Enforcement:

   • Supervisor ensures all precautions are followed.

6. Closure:

   • After work, area is inspected, declared safe, and permit closed.

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Responsibilities

• Issuer: Ensures safe conditions and approves work.

• Receiver: Executes work safely as per permit conditions.

• Safety Officer: Monitors compliance and audits the system.

• Workers: Follow instructions, use PPE, and report unsafe conditions.

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Enforcement and Audit

• Periodic inspection and verification of permit use.

• Training of all personnel on permit procedures.

• Records maintained for traceability and analysis.

• Violations may result in disciplinary action or retraining.

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Benefits of Permit System

• Ensures control over hazardous jobs.

• Prevents accidents due to unplanned work.

• Improves communication and coordination.

• Creates accountability and documentation.

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3.11 WELDING AND GAS CUTTING SAFETY

3.11.1 Welding and Gas Cutting

• Welding: Joining metals by applying heat, with or without filler metal.

• Gas Cutting: Using flame (oxy-acetylene or LPG) to cut metal.

• Common Types of Welding:

  • Arc Welding (MMAW, TIG, MIG)

  • Gas Welding (Oxy-Acetylene)

  • Resistance Welding

  • Brazing and Soldering

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Major Hazards

• Electric Shock: From live cables or electrodes.

• Fire and Explosion: Sparks near flammable material.

• Fumes and Gases: Toxic metal fumes (zinc, lead, cadmium).

• Radiation: Ultraviolet and infrared rays causing eye burns.

• Burns: From molten metal or hot slag.

• Cylinder Hazards: Leakage or explosion due to improper storage.

• Confined Space Risk: Oxygen deficiency, gas buildup.

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3.11.2 Precautions in Welding, Gas Cutting, Brazing and Soldering

A. General Safety Measures

• Only trained and certified welders to perform work.

• Obtain Hot Work Permit before starting.

• Keep fire extinguishers, sand buckets, and water hoses nearby.

• Remove or cover combustible materials within 10 meters.

• Ensure adequate ventilation or fume extraction.

• Use screens or curtains to protect others from arc flash.

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B. Personal Protective Equipment (PPE)

• Welding helmet with proper shade filter.

• Leather apron, gloves, and safety shoes.

• Flame-resistant clothing (no synthetic fabric).

• Respiratory protection where fumes accumulate.

• Ear protection during grinding or chipping.

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C. Cylinder and Gas Safety

• Store oxygen and fuel cylinders separately (minimum 5 meters apart).

• Keep cylinders upright and secured with caps.

• Use proper regulators and flashback arrestors.

• Check for leaks with soap solution, never with flame.

• Do not use oil/grease on oxygen fittings.

• Close valves when not in use; transport with trolley.

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D. Electrical Safety for Arc Welding

• Ensure proper earthing of welding machine.

• Use dry gloves and insulated electrode holders.

• Avoid welding in wet or damp conditions.

• Disconnect power before maintenance.

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E. Fire and Explosion Prevention

• Remove flammable vapors or liquids from area.

• Do not weld on drums, tanks, or containers unless cleaned and gas-free.

• Provide fire watch for 30 minutes after hot work.

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F. Brazing and Soldering Safety

• Use low-fume fluxes and work in ventilated area.

• Avoid inhaling fumes from lead-based solder.

• Cool parts before handling.

• Store fluxes and chemicals in labeled containers.

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G. Post-Work Safety

• Inspect area for residual sparks or smoldering materials.

• Close all gas valves and switch off equipment.

• Return cylinders to designated storage.

• Record completion in the permit logbook.