Workplace Safety: Tools, Machines, Electrical Hazards & Fire Prevention

Posted on May 3, 2024 in Other subjects

Workplace Safety

4. Tools

There are two types of tools: manual and motorized/dielectric.

4.1 Hand Tools

Most Frequent Risks
  • Blows and cuts
  • Projections of particles
  • Falling objects
  • Overstrain
Causes of Risks
  • Use of inappropriate tools
  • Misuse of tools, lack of operator training/overconfidence
  • Poor maintenance
  • Improper transportation
Measures to Avoid or Prevent Risks

These measures apply to both the tool and the worker:

  • Purchase good quality tools
  • Use tools appropriately
  • Perform proper maintenance
  • Conduct periodic reviews
  • Avoid using damaged tools
  • Store tools properly

Workers should also:

  • Transport tools properly in bags, tool boxes, or tool belts
  • Use protective equipment and measures
  • Assign tools to specific individuals

4.2 Motorized Tools

Motorized tools operate mechanically with a power source, reducing worker effort.

Most Frequent Risks

Same as hand tools, plus:

  • Noise (potential occupational deafness)
  • Vibrations (carpal tunnel syndrome, white finger syndrome)
  • Injuries from moving parts (entrapments, cuts)
  • Electrical contact
  • Burns (contact with hot surfaces)
Measures to Avoid Risks
Measures for Power Tools:
  • Check connection and grounding
  • Check condition of plugs and sockets
  • Use eye protection (welding arc)
  • Check condition and placement of cables
  • Ensure air vents are clear
  • Conduct proper maintenance, including insulation checks
  • Follow employer and manufacturer instructions
Measures for Pneumatic Tools:
  • Check hose connections
  • Check hoses for condition and impurities
  • Do not direct exhaust towards any operator
  • Use eye protection
Measures for Tools with Gunpowder:
  • Provide comprehensive safety devices
  • Install screens and guards

5. Machines

Machines should have instructions in the state’s official language, including:

  • Terms of Service
  • Worker positions
  • Safety instructions
  • Machine commissioning
  • Use
  • Storage and transportation instructions
  • Installation, assembly, and disassembly
  • Timing
  • Maintenance
  • Training instructions (if applicable)
  • Characteristics of compatible tools
  • Noise and vibration values

Machine safety involves many phases, from conception to transportation and maintenance.

Risks

Risks Associated with Moving Parts:
  • Entrapment and drag
  • Cuts
  • Crushing
  • Shear
  • Hooking
  • Injury from breakage and projection of elements
Cutting Fluids and Cooling:
  • Allergies, contact burns
  • Slips due to fluid accumulation on the floor
System Startup and Shutdown:

Risk of sudden outbursts

Electrical:

Electrical contacts

Measures to be Taken:

  • Acquire machines with CE marking
  • Request instructions from the manufacturer or importer
  • Perform regular and proper maintenance
  • Protect moving parts with guards
  • Avoid worker presence in hazardous areas
  • Install safety devices
  • Install visible emergency stop pushbuttons
  • Train employees in machine operation and safety measures
  • Ground electrical components
  • Anticipate and avoid risky behavior by workers
  • Ensure proper lighting

Elements of Protection in Machines

These are part of the machine and require maintenance, repair, and replacement.

There are two types:

  • Guards: Protection by physical barriers
  • Devices: Reduce risk, may be associated with a guard or not
Types of Guards:
  • Fixed guards: Solidly attached
  • Movable guards: Can be removed or opened without tools
  • Guards with locking systems: Machine stops automatically when opened and will not start while open
  • Guards with interlocking: Does not open until the machine has completely stopped. Machine must be reset when closed
Types of Devices:
  • Sensitive control: Machine runs only while being operated
  • Two-hand control: Requires simultaneous operation with both hands
Sensitive Protection Devices:
  • Intangible barriers
  • Mats

6. Electrical Hazard

6.1 Introduction

Electricity is widely used in homes and industries. It is readily accessible and easy to use but difficult to detect by the senses. These factors, especially the lack of prevention, make it a safety concern for workers. Electrical accidents are not very frequent, but they are often serious or very serious. In most cases, they are caused by human factors.

6.2 Concept

Electrical risk refers to the probability of accidents due to electricity powering facilities and equipment (generators, electrical panels, sockets, plugs, cables, tools, etc.). Electrical accidents primarily occur through contact but can also trigger other accidents.

The most important factors influencing accident severity are:

  1. Current intensity
  2. Contact time
  3. Current frequency (AC or DC)
  4. Human body resistance to current
  5. Trajectory of the electric current through the body

6.3 Types of Contacts

  • Direct contacts: Contact with live parts of materials and equipment
  • Indirect contact: Contact with masses accidentally energized

6.4 Analysis of Protection Measures Against Hazards

Several factors must be considered when analyzing these measures:

  • Whether work is done with or without voltage
  • When working with high voltage

7. Signaling

7.1 Introduction

Signaling is widely used, targeting people’s perception through stimuli like light and color. Safety signs alone do not provide protection or eliminate risks but prevent harm by influencing human behavior regarding hazards.

7.2 Types of Signals

  • Prohibition: Round, black pictogram on white background with red edges and a transverse bar
  • Obligation: Round with pictogram
  • Notice: Triangular, black pictogram on yellow background with black borders
  • Evacuation and rescue: Rectangular or square, white pictogram on green background
  • Fire-fighting: Rectangular or square, white pictogram on red background
  • Additional: Complementary to the above

7.3 Maintenance and Signal Conditions

Signals must be visible from different work points, considering their height. They should be cleaned regularly, kept in good condition, and replaced if necessary.

7.4 Light and Acoustic Signals

Light signals must be visible without causing glare and should not create confusion. Two light signals should not be used simultaneously at the same location. They should have an independent power source to remain lit during power failures.

Audible signals should be clearly audible above ambient noise. Two sound signals should not be used simultaneously.

8. Fire

8.1 Concept of Fire

Fire is an exothermic oxidation-reduction chemical reaction. When this reaction reaches a certain speed, fire occurs.

8.2 The Fire Triangle

The fire triangle theory states that three factors must be present for fire to start: fuel, oxidizer, and heat or activation energy.

8.3 Types of Fire

There are four types of fire, depending on the fuel.

8.4 Risk of Fire

Exposure to Heat:

Fatal injuries, dehydration, burns, etc.

Action from Fumes and Gases:

These cause most fire casualties and produce two types of effects:

  • Toxic effects: Depend on the harmfulness of gases produced during combustion (and therefore dependent on the fuel)
  • General effects: Asphyxia, disorientation, burns, panic, and hysterical behavior

* Rising temperatures and smoke often make evacuation impossible.

8.5 Elements of Prevention Against Fire

These measures prevent fire by addressing the factors that initiate it.

The Fuel:
  • Replace with a fuel with a lower flash point
  • Avoid spills and leaks, clean them if they occur
  • Use general or local extraction
  • Use cooling
  • Use solution or mixture
  • Use marking or coating
About the Oxidizing Agent:

Use atmospheres with low oxygen content.

On the Source of Ignition:
  • Thermal Focus: Avoid heat
  • Light Bulbs: Follow High Voltage Electrical Rules, avoid electrostatic charge, and install a lightning rod
  • Mechanical Focus: Perform maintenance
  • Chemical Focus: Proper storage, temperature control of processes

8.6 Elements of Fire Protection

In case of fire, it is advisable to wear clean clothes, know the location of doors, emergency exits, fire extinguishers, etc. Evacuation and rescue tasks should be planned and practiced.

8.6.1 Structural Protection

Walls, ceilings, and doors should be made of materials with high fire resistance. Fire resistance is indicated by the initials RF-XXX, where XXX indicates the minutes of fire resistance.

8.6.2 Detection

Consequences depend on how long the fire has spread. It is advisable to raise the alarm, extinguish the fire as soon as possible, and stay calm. The fire must be detected and the alarm or extinction system activated. The choice of detection system depends on the characteristics of the location, temperature, and combustible materials, which influence smoke, flames, and propagation speed. Different detection systems include human senses (least reliable), ion detectors, optical smoke detectors, flame detectors, and heat detectors. Alarms can be manual or automatic. Both alarms and detectors require periodic maintenance.

8.6.3 Extinction

Consider the effectiveness of different extinguishing agents for different types of fires. Here are some extinguishing agents and their characteristics:

  • Water: Cooling and smothering. Non-toxic. Reacts with light metals, is corrosive, and electrically conductive.
  • Physical Foam: Cooling and smothering, often used in basements as it does not flood. Conducts electricity.
  • Powder (dry and versatile): Inhibitors, suitable for type E fires, non-toxic, and non-conductive. Expensive.
  • Dry Ice: Coolant and smothering, suitable for electrical fires as it is a poor conductor. Ineffective outdoors and can cause asphyxiation in enclosed spaces.
  • Halogenated Derivatives: Inhibitors and suffocating, suitable for electrical fires and very clean. Only suitable for unoccupied premises.
8.6.3 Fire Extinguishers

Fire extinguishers contain pressurized extinguishing substances. They come in different capacities (less than 15 liters to over 250 liters). Portable fire extinguishers have the following external devices:

  • Pressure gauge
  • Nozzle for discharging the extinguishing agent
  • Discharge lever
  • Safety ring
  • Verification tag from the manufacturer or maintainer
  • Sticker (containing):
    • Fire type for which it is indicated and its effectiveness
    • Basic instructions for use
    • Precautions
    • Characteristics of the medium, temperature, etc.

Fire extinguishers must undergo periodic maintenance as follows:

Quarterly:

  • Check accessibility to the extinguisher, signaling, and apparent good condition
  • Visual inspection of registration, insurance, and seals
  • Visual inspection of nozzle, valve, manifolds, etc.

Annually: Personnel should verify extinguishing elements and record it in a check form.

Every 5 years: The registration plate is re-stamped up to a maximum of 3 times.