Any aspects of work or the work environment that have the potential to cause harm to an individual’s health, safety, or well-being. These hazards can lead to injuries, illnesses, or even death if not properly identified, assessed, and controlled.

Categories of Occupational Health Hazards

1. Physical Hazards
These are environmental factors that can cause harm to the body without necessarily touching it.

• Noise:

  • Examples: Loud machinery (factories, construction), power tools, airports, entertainment venues.

  • Health Effects: Noise-induced hearing loss (NIHL), tinnitus (ringing in ears), stress, increased blood pressure, sleep disturbances.

• Vibration:

  • Examples: Use of power tools (drills, jackhammers), driving heavy vehicles, operating machinery.

  • Health Effects: Hand-Arm Vibration Syndrome (HAVS) – “white finger disease,” carpal tunnel syndrome, back pain (whole-body vibration).

• Temperature Extremes (Heat and Cold):

  • Heat Stress Examples: Foundries, bakeries, outdoor work in hot climates, construction, firefighting.

  • Health Effects (Heat): Heat rash, heat cramps, heat exhaustion, heat stroke (life-threatening).

  • Cold Stress Examples: Outdoor work in cold climates, refrigerated warehouses, food processing.

  • Health Effects (Cold): Hypothermia, frostbite, chilblains, trench foot.

• Radiation:

  • Ionizing Radiation Examples: Medical X-rays, nuclear power plants, research labs.

  • Health Effects: Cell damage, cancer, radiation sickness.

  • Non-Ionizing Radiation Examples: Ultraviolet (UV) radiation from sun/welding, lasers, microwaves, radiofrequency fields (cell towers, MRI).

  • Health Effects: Sunburn, skin cancer, eye damage (UV, lasers), tissue heating (microwaves, RF).

• Illumination (Poor Lighting):

  • Examples: Inadequate lighting in offices, workshops; glare from screens or surfaces.

  • Health Effects: Eye strain, headaches, fatigue, increased risk of accidents.

• Pressure Extremes (Barotrauma):

  • Examples: Diving, working in pressurized tunnels or caissons, aviation.

  • Health Effects: Decompression sickness (“the bends”), ear/sinus pain, lung damage.

2. Chemical Hazards
These arise from exposure to harmful chemical substances in various forms (solids, liquids, gases, vapors, dusts, fumes, mists).

• Forms and Examples:

  • Solids: Lead, asbestos fibers.

  • Liquids: Solvents (e.g., benzene, toluene), acids, pesticides, cleaning agents.

  • Gases: Carbon monoxide, chlorine, ammonia.

  • Vapors: From volatile liquids like solvents.

  • Dusts: Silica dust (construction, mining), wood dust, flour dust.

  • Fumes: Welding fumes, metal fumes from smelting.

  • Mists: Paint spray, oil mists.

• Routes of Exposure: Inhalation (breathing in), skin absorption, ingestion (swallowing), injection.

• Health Effects:

  • Acute: Irritation (skin, eyes, respiratory tract), burns, poisoning, asphyxiation.

  • Chronic: Organ damage (liver, kidneys, lungs, nervous system), cancer (carcinogens), sensitization (allergies), respiratory diseases (e.g., silicosis, asbestosis, occupational asthma), reproductive problems.

• Workplaces: Manufacturing, agriculture, construction, healthcare (disinfectants, anesthetic gases), laboratories, cleaning services, auto repair.

3. Biological Hazards (Biohazards)
These involve exposure to living organisms or their byproducts that can cause disease.

• Examples:

  • Bacteria (e.g., Tuberculosis, Legionella, Anthrax).

  • Viruses (e.g., Influenza, Hepatitis B/C, HIV, SARS-CoV-2).

  • Fungi/Molds (e.g., Aspergillus, Histoplasma).

  • Parasites (e.g., Giardia, Malaria).

  • Bloodborne pathogens.

  • Animal dander, insect bites, poisonous plants.

• Workplaces: Healthcare facilities (hospitals, clinics, dental offices), laboratories, veterinary clinics, agriculture, waste management, emergency response, childcare facilities.

• Health Effects: Infections, allergies, zoonotic diseases (transmitted from animals to humans).

4. Ergonomic Hazards (Musculoskeletal Disorders – MSDs)
These relate to the design of the workspace, tasks, and equipment that can lead to strain, discomfort, and injury to the musculoskeletal system.

• Risk Factors:

  • Repetitive motions (e.g., typing, assembly line work).

  • Awkward postures (e.g., prolonged bending, reaching, twisting).

  • Forceful exertions (e.g., heavy lifting, pushing, pulling).

  • Static postures (e.g., prolonged sitting or standing).

  • Contact stress (e.g., resting wrists on hard edges).

  • Vibration (as mentioned under physical hazards).

• Workplaces: Offices (computer work), manufacturing, construction, healthcare (patient handling), agriculture, warehouses.

• Health Effects: Carpal tunnel syndrome, tendonitis, bursitis, back injuries (sprains, strains, disc problems), neck and shoulder pain, epicondylitis (“tennis elbow”).

5. Psychosocial Hazards
These are aspects of work design, organization, and management, as well as the social and environmental context of work, that can cause psychological harm or stress.

• Examples:

  • Workload and Pace: Excessive workload, tight deadlines, insufficient time to complete tasks.

  • Control: Low job control, lack of decision-making power.

  • Role Conflict/Ambiguity: Unclear job responsibilities, conflicting demands.

  • Work Relationships: Poor relationships with colleagues or supervisors, bullying, harassment, violence.

  • Support: Lack of support from management or colleagues.

  • Job Security: Fear of job loss, precarious work.

  • Shift Work/Long Hours: Disruption of circadian rhythms, fatigue.

  • Organizational Culture: Poor communication, lack of fairness or respect.

  • Traumatic Events: Exposure to violence, disasters, or critical incidents (e.g., for emergency responders, healthcare workers).

• Workplaces: All workplaces can have psychosocial hazards. High-stress occupations include healthcare, emergency services, teaching, customer service.

• Health Effects:

  • Psychological: Stress, anxiety, depression, burnout, PTSD, sleep problems, substance abuse.

  • Physical: Cardiovascular disease, musculoskeletal disorders, weakened immune system, gastrointestinal problems.

6. Safety Hazards
These are conditions that can cause immediate physical injury, illness, or death. Often overlap with other categories but focus on acute events.

• Examples:

  • Slips, trips, and falls (wet floors, uneven surfaces, clutter, working at height).

  • Struck-by objects (falling objects, moving equipment).

  • Caught-in or -between hazards (machinery with unguarded moving parts, collapsing trenches).

  • Electrical hazards (exposed wires, faulty equipment, contact with power lines).

  • Fire and explosions (flammable materials, faulty wiring, combustible dust).

  • Confined spaces (lack of oxygen, toxic atmospheres).

  • Working at height (ladders, scaffolds, roofs).

  • Vehicle-related accidents.

• Workplaces: Construction, manufacturing, agriculture, transportation, warehouses, any workplace with poor housekeeping or unsafe equipment.

• Health Effects: Cuts, bruises, fractures, amputations, burns, electrocution, asphyxiation, death.

Hierarchy of Controls (General Principle for Managing Hazards)
When addressing occupational hazards, a preferred order of control measures is followed:

1. Elimination: Physically remove the hazard.

2. Substitution: Replace the hazard with a less hazardous alternative.

3. Engineering Controls: Isolate people from the hazard (e.g., machine guards, ventilation systems).

4. Administrative Controls: Change the way people work (e.g., job rotation, training, safe work procedures).

5. Personal Protective Equipment (PPE): Protect the worker with PPE (e.g., gloves, respirators, safety glasses, hard hats) – considered the last line of defense.