Understanding Hazards

5.1 What Are Common Hazards?

Common hazards exist in every workplace. You need to recognise them and know what to do about them. They fall into six broad groups.

Mechanical hazards

Mechanical hazards come from the powered operation of tools and machinery, whether the power is from a machine or from a person. Examples are unguarded machines, plant and vehicles. A person may be harmed by:

• contact with or entanglement in machinery or equipment
• being crushed between a moving part and something fixed
• being struck by parts that are thrown out of the machine

Mechanical hazards can also be grouped by the type of injury: crushing, shearing, cutting and severing, entanglement, drawing in or trapping, impact, stabbing and puncture, friction and abrasion, and high pressure fluid injection.

Physical hazards

Physical hazards are substances or conditions that threaten a person's physical safety. Examples are fire, electricity, vibration and poor housekeeping. They are the most common hazards at work, and include unsafe conditions that cause injury, illness and death. The most common injuries come from tripping, slipping, falling from a height or on the level, and being struck by a falling object.

Chemical hazards

A chemical is a hazard because of properties that can harm people, property or the environment. Some chemicals occur naturally, such as arsenic or radon gas. Others are made for the home or for industry, such as paints, varnishes, bleaches and diesel. A chemical hazard can come from a substance used directly, such as glue, paint or cleaners, or from one generated by the work, such as fumes from soldering and welding.

How much harm results depends on how a chemical enters the body and how fast. The routes are absorption through the skin, ingestion through the mouth and inhalation into the lungs. Once inside, chemicals can cause skin disease, respiratory disease, cancer and birth defects, asphyxiation, disorders of the central nervous system, damage to organs and blood poisoning. Some substances harm after a single short exposure, which is an acute effect. Others show their harm only after prolonged or repeated exposure, which is a chronic effect.

Biological hazards

Biological hazards are organic substances or micro-organisms that threaten the health of people and other living things, including toxins produced by organisms. Examples are pathogenic bacteria, viruses, fungi and parasites. People who work with micro-organisms, for example in laboratories, face more risk. Other work that brings contact includes working with animals, with people who may be infectious, with waste, or in contaminated places. Common occupational infections include anthrax (from farm animals), hepatitis B and C (from people) and leptospirosis, or Weil's disease (from rodents).

Environmental hazards

Environmental hazards are conditions or events that can affect the environment and so harm people's health. They are often unnoticed until an accident happens. Examples are noise, poor lighting, unreasonable temperatures and dust. The work rate must be balanced against temperature, humidity, air movement, clothing, food and drink, body build and psychosocial factors, for the efficiency, comfort and safety of the worker.

Organisational hazards

Organisational hazards come from behaviour, workload, time pressure and deadlines. Studies show that these dimensions of work can be stressful: the timing of work, such as shift work; the content of the work; relations within the team; relations with supervisors; and the structure of the organisation.

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