What is Hazard and Risk ?

 What exactly is a hazard?

The definition of the word hazard can be perplexing. Often dictionaries do not give specific definitions or combine it with the term "risk". One dictionary, for example, defines hazard as "a danger or risk," which helps to explain why many people use the terms interchangeably.

There are many definitions of hazard, but the most common one when discussing workplace health and safety is:

A hazard is anything that has the potential to cause damage, harm, or adverse health effects to something or someone.

A hazard is defined as the possibility of harm or an adverse effect (for example, to people as health effects, to organisations as property or equipment losses, or to the environment).

The resulting harm is sometimes referred to as the hazard rather than the actual source of the hazard. Some may refer to tuberculosis (TB) as a "hazard," but the TB-causing bacteria (Mycobacterium tuberculosis) would be considered the "hazard" or "hazardous biological agent" in general.

What are some examples of hazards?

Workplace hazards can arise from a variety of sources. Any substance, material, process, or practise that has the potential to cause harm or adverse health effects to a person or property is an example of a general example. Refer to Table 1.

Table 1 Examples of Hazards and Their Effects
Workplace Hazard	Example of Hazard	Example of Harm Caused
Thing	Knife	Cut
Substance	Benzene	Leukemia
Material	Mycobacterium tuberculosis	Tuberculosis
Source of Energy	Electricity	Shock, electrocution
Condition	Wet floor	Slips, falls
Process	Welding	Metal fume fever
Practice	Hard rock mining	Silicosis
Behaviour	Bullying	Anxiety, fear, depression

Workplace hazards also include practices or conditions that allow uncontrolled energy to be released, such as:

 A falling object (potential or gravitational energy), 

 A runaway chemical reaction (chemical energy),

 The release of compressed gas or steam (pressure; high temperature),

 Hair or clothing entanglement in rotating equipment (kinetic energy), 

 Contact with electrodes of a battery or capacitor (electrical energy).

What exactly is risk?

A risk is the possibility or likelihood that a person will be harmed or suffer an adverse health effect as a result of being exposed to a hazard. It may also apply to situations involving the loss of property or equipment, as well as negative environmental consequences.

For example, the risk of developing cancer from smoking cigarettes could be expressed as:

"cigarette smokers are 12 times more likely than nonsmokers to die of lung cancer," or "the number of smokers who will develop lung cancer per 100,000 smokers" (actual number depends on factors such as their age and how many years they have been smoking).

These risks are expressed as the likelihood or probability of contracting a disease or being injured, whereas hazard refers to the agent responsible (i.e. smoking).

The following factors influence the degree or likelihood of risk:

the nature of the exposure: how frequently a person is exposed to a hazardous thing or condition (e.g., several times per day or once a year), 

how the person is exposed (e.g., inhaling a vapour, skin contact), and

 the severity of the effect. One substance, for example, may cause skin cancer while another may cause skin irritation. Cancer is a far more serious consequence than irritation.

What exactly is a risk assessment?

The process of risk assessment entails:

Determine the hazards and risk factors that may cause harm (hazard identification).

Analyze and assess the danger associated with that hazard (risk analysis, and risk evaluation).

Determine appropriate methods for removing the hazard or controlling the risk if the hazard cannot be removed (risk control).

What exactly is a negative health effect?

A general definition of adverse health effect is "any change in body function or the structures of cells that can lead to disease or health problems".

Negative health effects include:

• bodily injury,
• disease,
• change in the way the body functions, grows, or develops,
• effects on a developing fetus (teratogenic effects, fetotoxic effects),
• effects on children, grandchildren, etc. (inheritable genetic effects)
• decrease in life span,
• change in mental condition resulting from stress, traumatic experiences, exposure to solvents, and so on, and
• effects on the ability to accommodate additional stress.

What types of hazards are there?

A common method of categorising hazards is as follows:

• biological - bacteria, viruses, insects, plants, birds, animals, and humans, etc.,
• chemical - depends on the physical, chemical and toxic properties of the chemical,
• ergonomic - repetitive movements, improper set up of workstation, etc.,
• physical - radiation, magnetic fields, pressure extremes (high pressure or vacuum), noise, etc.,
• psychosocial - stress, violence, etc.,
• safety - slipping/tripping hazards, inappropriate machine guarding, equipment malfunctions or breakdowns.