Construction Safety: Hazards, Prevention, and Best Practices
Construction Safety: Hazards, Prevention, and Best Practices
Ergonomic Hazards in Construction Safety
Ergonomic hazards can lead to musculoskeletal disorders (MSDs) that can have a lasting impact on workers. Construction work often involves heavy lifting, repetitive motions, and awkward postures, which can all contribute to ergonomic hazards. Ergonomic hazards can cause consistent pain to workers, who often choose to work through that pain, but “working hurt” can not only lower productivity, but can cause lifelong pain and disability.
Examples of Ergonomic Hazards:
- Heavy Lifting
- Improper Grip
- Repetitive Hand Movement
Preventing ergonomic hazards is crucial for ensuring the safety and well-being of construction workers. Methods for preventing ergonomic hazards include promoting correct posture, using mechanical aids to lift heavy objects, taking frequent breaks to rest and stretch, and rotating job tasks to avoid repetitive motions. Employers can provide training on proper lifting techniques and ergonomic awareness, as well as conducting ergonomic assessments of the workplace to identify and address potential hazards.
Excavation and Filling Safety Provisions During Excavation
Excavation is the process of removing earth, rock, or other materials from a site to create a hole or cavity. Filling is the process of replacing the excavated material back into the hole or cavity.
Excavation and filling are common activities in construction projects, but they can be hazardous if not properly managed.
Safety Provisions During Excavation:
- Fencing, guarding, or barricading the area to prevent falls of persons, vehicles, or livestock into the excavated area.
- Erecting warning signs and providing adequate illumination during night hours to warn pedestrians and vehicular traffic.
- Preventing external vibrations due to rail/road traffic.
- Not allowing workers to work on steep slopes above each other.
- Not commencing excavation of earthwork below the level of any foundation of a building or structure unless adequate steps are taken to prevent danger.
- Taking additional precautions to prevent slides, slips, or cave-ins when excavations are made in locations subject to vibrations from rail-road or highway traffic, etc.
- Providing ladders in all trenches 1.5 m or more in depth.
- Adequately lighting excavation areas for night work.
- Adequately illuminating public sidewalks during hours of darkness and providing warning about the excavation.
Loose stones, projecting clumps of earth, and unstable material that may come down on workers in a trench should be removed, and the excavated sides should be adequately braced and the trench suitably guarded.
Stockpiles of loose materials should not be located in the immediate vicinity of overhead power lines, and materials should not be piled against walls as it may endanger the walls.
Excavated materials should not be stacked within 1/3 rd of depth of the pit or 1 m, whichever is more, away from the edge of any excavation, and should be stored and retained so as to prevent it from falling or sliding back into the excavation and to prevent excessive pressure upon the side of the excavation.
Excavations carried out at any place to which the public or cattle have or might gain access must be guarded to avoid danger to people. A fence 1 m high or a combination of signs, barriers, lights, markers, flags, or sentries may be necessary to provide adequate protection for the public and employees. These safety devices must be properly maintained until the excavation is completed.
Blasting Safety
Blasting is a process of reducing rocks or hard soil into fragments with the help of explosives.
The blasting operation involves drilling of holes, installation of a detonator and charge, detonating the charge, and removal of debris.
For the safety of workers, red flags shall be prominently displayed around the area where blasting operations are to be carried out.
All workers at the site shall withdraw to a safe distance of at least 200 meters from the blasting site.
An audio warning by blowing whistle shall be given before igniting the fuse.
The blasting operation shall be carried out under the supervision of trained personnel.
Types of Fire Extinguishers and Their Uses
Class A: Solid materials such as wood or paper, fabric, and some plastics
Class B: Liquids or gas such as alcohol, ether, gasoline, or grease
Class C: Electrical failure from appliances, electronic equipment, and wiring
Class D: Metallic substances such as sodium, titanium, zirconium, or magnesium
Class K: Grease or oil fires specifically from cooking
Dry Powder Types: These fire extinguishers and agents are intended for use on Class D fires and specific metals, following special techniques and manufacturer’s recommendations for use.
Fire Protection Methods
Fire Prevention: The best way to protect against fire is to prevent it from occurring in the first place. This can be achieved through proper storage and handling of flammable materials, regular maintenance of electrical equipment, and proper disposal of smoking materials.
Fire Detection: Early detection of a fire is critical to minimizing damage and preventing injury. Smoke detectors, heat detectors, and flame detectors are common fire detection methods.
Fire Suppression: Once a fire has been detected, it is important to suppress it as quickly as possible. This can be achieved through the use of fire extinguishers, sprinkler systems, and other fire suppression systems.
Evacuation: In the event of a fire, it is important to evacuate the building as quickly and safely as possible. This requires having a well-planned evacuation route and ensuring that all occupants are aware of the plan.
Training: Proper training is essential for effective fire protection. This includes training on fire prevention, fire detection, fire suppression, and evacuation procedures.
Maintenance: Regular maintenance of fire protection systems is essential to ensure that they are functioning properly when needed. This includes testing and inspection of fire extinguishers, sprinkler systems, and other fire suppression systems.
Emergency Response Planning: Having a well-planned emergency response plan in place can help to minimize damage and prevent injury in the event of a fire. This includes having a designated emergency response team and ensuring that all occupants are aware of the plan.
Manual Material Handling Safety
Definition: Manual material handling refers to the process of moving, lifting, carrying, and transporting objects by hand or with the help of basic tools such as dollies, carts, and hand trucks.
Importance: Manual material handling is an essential part of many jobs and industries, including manufacturing, construction, warehousing, and retail. It is also a common cause of workplace injuries and can result in musculoskeletal disorders, strains, sprains, and other injuries.
Risk Factors: The risk of injury associated with manual material handling can be influenced by a variety of factors, including the weight and size of the object being handled, the distance it needs to be moved, the frequency of the task, the posture and technique used, and the physical condition of the worker.
Prevention: The risk of injury associated with manual material handling can be reduced through a variety of prevention strategies, including proper training on lifting and handling techniques, the use of mechanical aids such as dollies and carts, the implementation of ergonomic work practices, and the use of personal protective equipment.
5. Ergonomics: Ergonomics is the science of designing work tasks, tools, and equipment to fit the capabilities and limitations of the human body. Ergonomic principles can be applied to manual material handling tasks to reduce the risk of injury and improve worker safety and comfort.
6. Training: Proper training is essential for safe and effective manual material handling. Workers should be trained on proper lifting and handling techniques, as well as on the use of mechanical aids and personal protective equipment.
7. Risk assessment: Employers should conduct a risk assessment of manual material handling tasks to identify hazards and implement appropriate prevention strategies. This may include modifying work practices, providing mechanical aids, or redesigning workstations to reduce the risk of injury.
Hazards with Manual Material Handling
The hazards associated with manual material handling can include:
1. Musculoskeletal disorders (MSDs): These are injuries or disorders that affect the muscles, tendons, ligaments, nerves, and other soft tissues. MSDs are the most common type of injury associated with manual material handling and can result from lifting, pushing, pulling, or carrying heavy loads.
2. Strains and sprains: These are injuries to the muscles, tendons, or ligaments that can result from overexertion, sudden movements, or awkward postures.
3. Back injuries: These are injuries to the back that can result from lifting, twisting, or bending. Back injuries can be particularly debilitating and can result in long-term disability.
4. Slips, trips, and falls: These are hazards that can result from carrying heavy loads, working on uneven surfaces, or working in areas with poor lighting.
5. Crush injuries: These are injuries that can result from being caught between or under heavy objects.
6. Repetitive motion injuries: These are injuries that can result from performing the same motion over and over again, such as lifting or carrying heavy loads.
7. Fatigue: This is a hazard that can result from performing manual material handling tasks for extended periods of time without adequate rest or recovery time.
Grinding is a common process used in many industries to shape and finish metal, wood, and other materials. However, grinding machines can be hazardous if they are not used correctly. Here are some key points about safety in grinding:
– All types of grinding machines, whether pedestal, bench mounted, free-standing, or portable, can be potentially hazardous if they are not well maintained and used correctly.
– Hazards associated with grinding include flying particles, dust, and sparks, as well as shattering abrasive wheels while in motion, which can cause severe injury to both the user and others.
– Guards must be provided and adjusted properly as per the manufacturer’s manual.
– Before use, check the manufacturer’s stated running speeds, or markings on the grinder, and grinder wheel for the maximum speed that it can be used.
– Replace damaged guards because if an abrasive wheel breaks while rotating, it can cause a serious injury.
– Workers should wear appropriate personal protective equipment (PPE), such as eye protection, hearing protection, and respiratory protection, when grinding.
– Workers should also be trained on proper grinding techniques, including how to hold the workpiece, how to adjust the grinding wheel, and how to avoid contact with the rotating wheel.
Arc Welding
– Arc welding is a type of welding process that uses an electric arc to create heat to melt and join metals.
– A power supply creates an electric arc between a consumable or non-consumable electrode and the base material using either direct (DC) or alternating (AC) currents.
– Personal protective equipment (PPE) is essential for arc welding safety. Welders should wear eye protection, such as goggles or safety glasses, to protect against infrared radiation. They should also wear protective clothing, such as a flameproof apron, gloves, cap or helmet, and boots.
– Welding machines should be properly grounded/earthed, and the switchboard and fuse should be in good condition.
– Welders should not overload or overheat the welding machine.
– Welders should be trained to recognize and respond to electrical hazards, such as shock and electrocution. They should avoid touching the electrode or metal parts of the welding circuit when the electrode is live.
– Welders should be trained to recognize and respond to fire hazards, such as sparks and hot metal. They should keep a fire extinguisher nearby and avoid welding near flammable materials.
Gas welding:
– Gas welding is a type of welding process that uses gases like acetylene and oxygen to produce flames.
– Acetylene is flammable and hazardous, and it has the ability to ignite and condense. Oxygen helps other substances to burn faster and can explode if exposed to fire.
– Personal protective equipment (PPE) is essential for gas welding safety. Welders should wear eye protection, such as goggles or safety glasses, to protect against infrared radiation. They should also wear protective clothing, such as a flameproof apron, gloves, cap or helmet, and boots.
– Welding machines should be properly grounded/earthed, and the switchboard and fuse should be in good condition.
– Welders should not overload or overheat the welding machine.
– Welders should be trained to recognize and respond to backfires and flashbacks. In the event of a backfire, the oxygen valve should be closed first, followed immediately by the acetylene valve. In the event of a flashback, all hoses should be replaced with new ones.
– Welders should be trained to recognize and respond to fire hazards, such as sparks and hot metal. They should keep a fire extinguisher nearby and avoid welding near flammable materials.
– Welders should be trained to recognize and respond to fumes and gases, such as nitrogen oxides and ozone. They should work in a well-ventilated area and use local exhaust ventilation to remove fumes and gases from the work area.
– Flame arrestors must be fitted in acetylene and oxygen cylinder lines. One of them should be fitted beside the low-pressure regulator and the other near the torch. Higher pressure should release on oxygen than acetylene to avoid acetylene flame from going back. However, acetylene should not be used when welding at a pressure exceeding 1bar of atmosphere gauge to avoid explosion.
– Industries or shops where gas welding is used should have proper ventilation, lighting, walkways, store, escape route, safety poster, etc. The floor should be kept clean, free from water, grease, and oil. Fire extinguishers should be easily accessible, and welded jobs should be properly stored.
Machine Safeguard Devices:
Presence-Sensing Devices:
Use light or radiofrequency sources to interrupt machine cycles.
Stop the machine if the light or electric field is broken, preventing entry into the danger area.
Examples: Photoelectric devices, electromechanical sensing devices.
Photoelectric Presence-Sensing Device:
Uses light beams to interrupt machine cycles.
If the light beam is broken, the machine stops or activates a stopping mechanism.
Prevents the operator’s hand from entering the danger zone.
Electromechanical Sensing Device:
Involves a probe or contact bar that descends during the machine cycle.
If an obstruction prevents full descent, the control circuit prevents machine activation.
Ensures safe machine operation by detecting obstacles in the danger area.
Pullback Devices:
Employ cables attached to the operator’s hands, wrists, and/or arms.
Allows access to the point of operation when the machine is idle.
Automatically withdraws hands when the machine begins its cycle.
Restraint Devices:
Use cables or straps attached to the operator’s hands within a safe area.
Restricts hand movement to a predetermined safe zone.
No extending or retracting action required.
Safety Trip Controls:
Provide a quick means to deactivate the machine in emergencies.
Pressure-sensitive body bar deactivates the machine when depressed.
Critical positioning to stop the machine before reaching the danger area.
Two-Hand Control Devices:
Require constant, concurrent pressure by the operator to activate the machine.
Operator’s hands must be on control buttons at a safe distance during the machine’s cycle.
Involves part-revolution clutch, brake, and brake monitor in power presses.
Two-Hand Trip Devices:
Require concurrent application of both control buttons to activate the machine.
Hands are free after the machine cycle is initiated.
Located away from the danger zone to prevent using hands or other body parts to trip the machine.
Hooks:
– Before use, hooks must be inspected by an experienced rigger .
– Remove a hook from service if any of the following are in evidence: cracks, nicks, or gouges; twist exceeding 10 degrees from plane; damage or malfunction to the latch .
– Hooks should be lubricated regularly to prevent rust from developing .
– Hooks should be stored in a dry place to prevent rust from developing .
– Hooks should be kept clean and free from dirt and debris .
– Hooks should be kept away from heat sources and chemicals that could damage them .
– Hooks should be properly stored to prevent damage .
Clamps:
– To make sure the clamp works efficiently, it is important to keep all the parts clean. Any dirt may damage the ability of the tool and stain the surface of the workpiece during clamping .
– After every use, wipe the clamp with a dry cloth to clear any dust or debris that may have built up .
– Regularly oil all the moving parts to keep them in tip-top condition and prevent rust from developing .
– Store the clamp in a safe and dry place, such as on a shelf in a garage or work shed .
– Inspect the clamp before each use to ensure that it is in good condition .
– Replace any damaged or worn parts immediately .
– Do not use a clamp that is damaged or worn .
– Do not exceed the maximum clamping force of the clamp .
– Do not use the clamp for any purpose other than its intended use .