Understanding the difference between a hazard and a risk

The terms ‘hazard’ and ‘risk’ are often used interchangeably, however, they are two very distinct terms. Table 4 shows a range of definitions of the terms Hazard and Risk, at times indicating a specific context within which it is being applied. However, the descriptions reveal similar keywords and in principle refer to the same situation:

• For “hazard”: Something that has the potential or ability to cause harm or other adverse effects. • For “risk”: The likelihood that the hazard will be realised, and to what severity.

Table 4. Definitions of Hazard and Risk

Hazard Risk

A biological, chemical or physical agent in, or condition of, food with the potential to cause an adverse health effect (CAC, 2016)

The probability of an adverse health effect and the severity of that effect, consequential to a hazard(s) in food (CAC, 2016)

Any part of a production chain or a product that has the potential to cause a safety problem (McDonough, 2002)

Probability that the hazard will occur (Cusato et al., 2012)

Something (e.g. an object, a property of a

substance, a phenomenon or an activity) that can cause adverse effects (Kilpatrick et al., 2008)

A combination of the likelihood and severity of the associated potential adverse events (Cure et al., 2014)

A biological, chemical, or physical agent that is reasonably likely to cause illness or injury in the absence of its control (NACMCF, 1997)

The likelihood that a hazard will actually cause its adverse effects, together with a measure of the effect (Kilpatrick et al., 2008)

The intrinsic ability of an agent or situation to cause adverse effects to a target such as people, environment, etc. (Scheer et al., 2014)

The possibility of acquisition or infection of patients or healthcare workers arising from activities within a healthcare facility (NHMRC, 2010)

A situation with the potential to cause harm (NPSA, 2006, 2007a)

The combination of likelihood and consequence of hazards being realised (NPSA, 2006, 2007a) A potential source of harm or adverse health

effect on a person or persons (H&SA, 2017)

The likelihood that a person may be harmed or suffers adverse health effects if exposed to a hazard (H&SA, 2017)

For example, if there was a spill of water on the floor in a corridor then that water would present a slip hazard to people walking there, but if no-one enters the corridor, then there is no risk of someone slipping. However, if the corridor is used, then for each person there are individual factors that can

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influence the risk if they step in the water, such as the texture of the sole of their footwear, the speed they are moving, their stability etc. The optimum resolution would be to remove the hazard, by wiping up the water, however, if this is not possible then preventing access to the corridor would mean the hazard remains but the risk is removed. Alternatively, placing a warning sign near the spillage, would reduce the risk, but it would be subject to people seeing, understanding, and acting on the sign’s warning.

To put it more simply, Hazard + Risk = Incident (Singley, 2004), and Risk = Hazard x Dose, where ‘dose’ can relate to ‘exposure’ (Ropeik & Gray, 2002) or ‘vulnerability’ (WHO, 2011b). Thus, removal of either the hazard or risk prevents an incident from occurring, and a hazard poses no risk if there is no contact with it, or if there is immunity or resilience to the adverse effect.

A medicine or other form of healthcare treatment could be described as a hazard if it has the potential to cause harm. However, the risk of that harm may be very small provided effective controls/measures are in place. If a patient could suffer harm as a result of the medical intervention, the chance of the harm occurring at a given severity may be described as a clinical risk (NPSA, 2007a). Clinical risk is the probability of a patient being subject to an adverse event (i.e., an unintended injury or complication that results in disability at the time of discharge, death or prolonged hospital stay) caused by health care management rather than by the patient’s underlying disease process (Bonfant et al., 2010).

Considering the perspective of this research, the contaminated device is the hazard, as it has the potential to cause harm by being a source of viable pathogenic bacteria that can survive contact transfer. Whilst acknowledging the evidence in previous chapters, that not all devices carry pathogenic organisms and there is variation in the levels of contamination, it is impossible to differentiate without subjecting the devices to bacterial testing. So, erring on the side of safety, it has to be assumed that all devices are potentially contaminated unless they are subjected to effective decontamination. As such, the associated risks relate to:

• contact transfer taking place, the ‘exposure’, and;

• the environment and the people present, the ‘vulnerability’.

As previously identified, MCDs are constantly being taken into the perioperative environment, introducing a hazard relating to the carriage of microorganisms from outside this area. Patients undergoing surgery are vulnerable to infection for many reasons, including age, pre-existing ill-health, their natural barriers to infection being breached e.g. skin being cut, and the immuno-suppressant effects of drugs and medicines they are given. If the contaminated device comes into contact with people or objects, then transfer may occur, which introduces bacteria into the environment, or adds to the bacterial load on the device. This in turn may be transferred later, during the same procedure, a

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subsequent one, or even outside the care environment when the device is taken home. Analysis of this hazard in the perioperative environment will determine if the risks are realised, and if so, can they be removed or reduced to acceptable levels. There are three possible outcomes to the evaluation process:

1. No hazards are identified, which means that regardless of any bacterial contamination on the devices, there is no risk.

2. Hazard(s) are identified, which can be controlled; again, this means there is no risk, providing the corrective actions are performed.

3. Hazard(s) are identified which cannot be controlled; this would indicate that contaminated devices are a risk and should be excluded from this environment.