Hazard and Risk
A Hazard is a potential source of harm or adverse health effect on a person or persons’. ‘Risk is the likelihood that a person may be harmed or suffers adverse health effects if exposed to a hazard.’ The terms Hazard and Risk are often used interchangeably but this simple example explains the difference between the two. If there was a spill of water in a room then that water would present a slipping hazard to persons passing through it. If access to that area was prevented by a physical barrier then the hazard would remain though the risk would be minimised.
Categories of Risk and Hazards
The level of risk is often categorized upon the potential harm or adverse health effect that the hazard may cause the number of times persons are exposed and the number of persons exposed. For example exposure to airborne asbestos fibers will always be classified as high because a single exposure may cause potentially fatal lung disease, whereas the risk associated with using a display screen for a short period could be considered to be very low as the potential harm or adverse health effects are minimal. Hazards should be ranked according to their potential severity as a basis for producing one side of the risk equation.
A simple three-point scale can be used such as low, moderate and high. A more complex severity rating scale has been proposed by Holt and Andrews (1993), as follows:
- Catastrophic (imminent danger exists, hazard capable of causing death and illness on a wide scale);
- Critical (hazard that can result in serious illness, severe injury, property and equipment Damage);
- Marginal (hazard that can cause illness, injury, or equipment damage, but the results would not be expected to be serious); and
- Negligible (hazard that will not result in serious injury or illness; remote possibility of damage beyond minor first-aid case).
Risk assessments are concerned with looking for hazards and estimating the level of risk associated with them. The purpose of risk assessments is, of course, to initiate preventive action because they enable control measures to be devised on the basis of an understanding of the relative importance of risks.
There are two types of risk assessment.
The first is quantitative risk assessment, which produces an objective probability estimate based upon risk information that is immediately applicable to the circumstances in which the risk occurs.
The second is qualitative risk assessment, which is more subjective and is based on judgments backed by generalized data. Quantitative risk assessment is preferable where data are available. Qualitative risk assessment may be acceptable if there are little or no specific data available.
Risk assessment starts with identification of hazards. Once the hazards have been identified it is necessary to assess how high the risks are. This involves answering three questions: What is the worst result? How likely is it to happen? And how many people could be hurt if things go wrong? A probability rating system can be used such as the one recommended by Holt and Andrews: Probable – likely to occur immediately or shortly; reasonably probable – probably will occur in time; Remote – may occur in time; and extremely remote – unlikely to occur.
Risk assessment should lead to action. The type of action can be ranked in order of potential effectiveness in the form of a ‘safety precedence sequence’ and include:
- Hazard elimination (use of alternatives, design improvements, change of Process);
- Substitution (for example, replacement of a chemical with one which is less Risky);
- Use of barriers (removing the hazard from the worker or removing the worker from the hazard.);
- Use of procedures (limitation of exposure, dilution of exposure, safe systems of work depending on human response);
- Use of warning systems (signs, instructions, labels); and
- Use of personal protective clothing (this depends on human response and is used as a side measure only when all other options have been exhausted).
Once you hazards have been ranked, appropriate methods to control each hazard should be established. Hazard control methods are often grouped into the following categories:
- Elimination or substitution (Elimination of the hazard is not always achievable though it does totally remove the hazard and thereby eliminates the risk of exposure. An example of this would be that petrol station attendants are no longer exposed to the risk of lead poisoning following the removal of lead from petrol products);
- Engineering controls Engineering (Controls involve redesigning a process to place a barrier between the person and the hazard or remove the hazard from the person, such as machinery guarding, proximity guarding, extraction systems or removing the operator to a remote location away from the hazard);
- Administrative controls (Administrative controls include adopting standard operating procedures or safe work practices or providing appropriate training, instruction or information to reduce the potential for harm and/or adverse health effects to person(s). Isolation and permit to work procedures are examples of administrative controls); and
- Personal protective equipment.
Types of Hazard
There are generally four main of Hazards: Physical, chemical, biological and psychological.
Physical hazards are conditions or situations that can cause the body physical harm or intense stress. Physical hazards can be both natural and human made elements. Physical hazards are the most common hazards and are present in most workplaces at some time. This category also includes the hazards from working in confined spaces, being hit by flying objects, caught in explosions, falling from heights and tripping on obstacles, electrical hazards, unguarded machinery, Temperature hazards, exposed moving parts, constant loud noise, vibrations, lighting hazards, spills etc.
Chemical hazards are substances that can cause harm or damage to the body, property or the environment. Chemical hazards can be both natural and human made origin. Chemicals can affect the skin by contact or the body either through the digestive system or through the lungs if air is contaminated with chemicals, vapor, mist or dust. There can be an acute (immediate) effect, or a chronic (medium to long-term) effect from the accumulation of chemicals or substances in or on the body. Examples include: cleaning products and solvents, vapors and fumes, carbon monoxide or other gases, gasoline or other flammable materials.
Biological hazards are biological agents that can cause harm to the human body. Biological hazards come from working with people, animals or infectious plant material. They can be viruses, parasites, bacteria, food, fungi, and foreign toxins. Examples include: blood or other bodily fluids, bacteria and viruses, insect bites, animal and bird droppings.
Psychological hazards are created during work related stress or a stressful environment. The most common are Ergonomic hazards which occur when the type of work you do, your body position and/or your working conditions put a strain on your body.
Ergonomics hazards are difficult to identify because an employee does not immediately recognize the harm they are doing to his health. Examples include: poor lighting, improperly adjusted workstations and chairs, frequent lifting, repetitive or awkward movements. Other psychological hazards include stress, fatigue, the effects of shift work, and even assaults from other people.
Causes of Workplace Accidents
There are three basic causes of workplace accidents chance occurrence, unsafe conditions, and employees’ unsafe acts and chance occurrences which are in most cases beyond the management’s control. However, unsafe conditions are a main cause of accidents. They include things like: Improperly guarded equipment; Defective equipment; Hazardous procedures in, on, or around machines or equipment; Unsafe storage such as congestion, overloading; Improper illumination; and Improper ventilation.
The solution to these causes is to identify and eliminate the unsafe conditions and observing the laid down Occupational Safety and Health Act (OSHA) standards.
Unsafe acts can undo even the best attempts to reduce unsafe conditions. It may seem that some people are simply accident prone, However, there is growing evidence that people with specific traits may indeed by accident prone. For example, people who are impulsive, sensation seeking, extremely extroverted and less conscientious are more likely to have accidents. A person who is accident prone on one job may not be so on a different job. Examples of unsafe acts include: distraction by cell phones, eating, drinking while working and so on.
Other causes of accidents involve workplace climate or psychology such as strong pressure within the organization to complete the work as quickly as possible , employees who are under a great deal of stress, and a poor safety are examples of psychological conditions leading to accidents.
Hazards and Risks in an Organization
Most accidents are caused by a few key activities. Risk assessors are advised to concentrate initially on those activities that could cause serious harm. The following are typical activities where accidents happen or there are high risks:
- receipt of raw materials, e.g. lifting, carrying;
- stacking and storage, e.g. falling materials;
- movement of people and materials, e.g. falls, collisions;
- processing of raw materials, e.g. exposure to toxic substances;
- maintenance of buildings, e.g. roof work, gutter cleaning;
- maintenance of plant and machinery, e.g. lifting tackle, installation of equipment;
- using electricity, e.g. using hand tools, extension leads;
- operating machines, e.g. operating without sufficient clearance, or at an unsafe speed;
- not using safety devices;
- failure to wear protective equipment, e.g. hats, boots, clothing;
- distribution of finished jobs, e.g. movement of vehicles;
- dealing with emergencies, e.g. spillages, fires, explosions;
- health hazards arising from the use of equipment or methods of working etc.