In this module
Objectives covered: LO 2.2.1. By the end you will be able to:
- Sort workplace hazards into the main groups used by OSHA and ISO.
- Give at least two examples of each hazard group from Bangladesh industry.
- Recognise health hazards that act slowly as well as safety hazards that act fast.
2.1 Safety hazards and health hazards
Safety hazards usually cause injury quickly: a cut, a fall, a burn, an electric shock. Health hazards often cause illness slowly, over months or years: hearing loss from noise, lung disease from dust, back pain from lifting. Both are equally important. Health hazards are easy to miss because nothing seems to happen today.
2.2 The main hazard groups
| Group | What it includes | Bangladesh examples |
|---|---|---|
| Mechanical | Moving parts, sharp edges, crushing, entanglement, flying parts | Knitting and sewing machines, rice mill rollers, conveyor belts in cement plants |
| Electrical | Shock, arc flash, electrical fire | Overloaded distribution boards in garment factories, illegal hooking, substation work |
| Physical | Noise, vibration, heat, cold, radiation, poor lighting | Weaving sheds above 95 dB(A), steel re-rolling mills, boiler rooms |
| Chemical | Liquids, dusts, fumes, gases and vapours that are toxic, corrosive or flammable | Dye kitchens, tanneries in Savar, fertiliser plants handling ammonia, paint shops |
| Fire and explosion | Flammable gas, liquids, dust, pressure vessels | Gas lines, LPG cylinders, chemical warehouses, boilers |
| Biological | Bacteria, viruses, mould, animal waste | Hospitals, poultry and dairy farms, sewage and ETP work |
| Ergonomic | Heavy lifting, awkward posture, repetition, poor workstation design | Sack handling at ports, sewing operators sitting for 10 hours |
| Work at height and gravity | Falls of people and falling objects | Building construction, scaffolds, roof work, ship breaking |
| Confined space | Low oxygen, toxic gas, engulfment | Septic tanks, water reservoirs, ship tanks, silos |
| Psychosocial | Stress, long hours, harassment, violence, fatigue | Night shifts, production pressure, isolated security staff |
2.3 Energy is the root of most hazards
A useful way to find hazards is to ask: where is the energy? Most injuries happen when energy is released in an uncontrolled way. Look for:
- Electrical energy in cables, panels and batteries.
- Mechanical energy in moving parts, springs and flywheels.
- Pressure in compressed air, steam, hydraulics and gas cylinders.
- Gravity: anything or anyone that can fall.
- Chemical energy: flammable or reactive substances.
- Thermal energy: hot surfaces, steam, molten metal.
- OSHA 1910 Subpart O (machine guarding), Subpart S (electrical), 1910.95 (noise), 1910.1200 (hazard communication, GHS labels and SDS).
- GHS (Globally Harmonized System) pictograms identify chemical hazards on labels.
- ISO 45001 asks you to consider routine and non-routine activities, people, equipment, materials and the work environment.
In ship-breaking yards in Sitakunda, Chattogram, one job can contain almost every hazard group: falls from height, falling steel plates, gas-cutting fire, toxic fumes from old paint, asbestos, confined spaces inside tanks, heat and heavy manual handling. Yards that have improved their record first listed every hazard group for each job, then attacked the biggest ones, such as gas-freeing tanks before cutting.
Learning Check
Answer these two questions to check your understanding. You can try again as many times as you like.