damage or loss to property, plant, materials or the environment or a loss of a business opportunity’.
Other authorities define an accident more narrowly by excluding events that do not involve injury or ill-health. This book will always use the HSE definition.
2. Incident:
– near miss: an event that, while not causing harm, has the potential to cause injury or ill-health. (In this guidance, the term near miss will be taken to include dangerous occurrences);
– Xundesired circumstance: a set of conditions or circumstances that have the potential to cause injury or ill-health, e.g. untrained nurses handling heavy patients.
3. Dangerous occurrence: one of a number of specific, reportable adverse events, as defined in the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR).
4. Immediate cause: the most obvious reason why an adverse event happens, e.g. the guard is missing;
the employee slips, etc. There may be several immediate causes identified in any one adverse event.
5. Root cause: an initiating event or failing from which all other causes or failings spring. Root causes are generally management, planning or organisational failings.
6. Underlying cause: the less obvious ‘system’
or ‘organisational’ reason for an adverse event happening, e.g. pre-start-up machinery checks are not carried out by supervisors; the hazard has not been adequately considered via a suitable and sufficient risk assessment; production pressures are too great.
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5.2.3 Accident triangles and their limitation
In 1969, F. E. Bird collected a large quantity of accident data and produced a well-known triangle (Figure 5.7).
It can be seen that damage and near miss incidents occur much more frequently than injury accidents and, therefore, may be a good indicator of risks. The study also shows that most accidents are predictable and avoidable.
There are other accident ratio triangles which have been produced, for example by Heinrich (see Chapter 3) and the HSE. They are all very similar despite different actual numbers but the concept has limitations as recent research in the USA by Behavioral Science Technology (BST) has shown.
The safety triangle, or pyramid, states that reducing minor injuries or near misses (the large number at the bottom) leads to a proportionate reduction in severe injuries and deaths (the small number at the top).
However, statistics over the past 10 years or so have shown that minor injuries have steadily declined while 3. Over 7-day injury/ill-health: where the person
affected is unfit to carry out his or her normal work for more than seven consecutive days;
4. Minor injury: all other injuries, where the injured person is unfit for his or her normal work for less than seven days;
5. Damage only: damage to property, equipment, the environment or production losses.
Figure 5.6 demonstrates the difference between an accident, near miss and undesired circumstances.
Each type of event/incident gives the opportunity to:
X
u check performance;
X
u identify underlying deficiencies in management systems and procedures;
X
u learn from mistakes and add to the corporate memory;
X
u reinforce key health and safety messages;
X
u identify trends and priorities for prevention;
X
u provide valuable information if there is a claim for compensation;
X
u help meet legal requirements for reporting certain incidents to the authorities.
(a) (b)
(c)
Figure 5.6 (a) Accident; (b) near miss (includes dangerous occurrence) damage only; (c) undesired circumstances
are usually determined by their outcomes or consequences. Should every accident be
investigated or only those that lead to serious injury?
In fact the main determinant is the potential of the accident to cause harm rather than the actual harm resulting. For example, a slip can result in an embarrassing flailing of arms or, just as easily, a broken leg. The frequency of occurrence of the accident type is also important – a stream of minor cuts from paper needs looking into.
As it is not possible to determine the potential for harm simply from the resulting injury, the only really sensible solution is to investigate all accidents.
The amount of time and effort spent on the
investigation should, however, vary depending on the level of risk (severity of potential harm, frequency of occurrence). The most effort should be focused on significant events involving serious injury, ill-health or losses and events which have the potential for multiple or serious harm to people or substantial losses. These factors should become clear during the accident investigation and be used to guide how much time should be taken.
Figure 5.8 has been developed by the Health and Safety Executive (HSE) to help to determine the level of investigation which is appropriate. The potential worst injury consequences in any particular situation should be considered when using the figure. A particular incident like a scaffold collapse may not have caused an injury but had the potential to cause major or fatal injuries.
In a minimal-level investigation, the relevant supervisor will look into the circumstances of the accident/incident and try to learn any lessons which will prevent future incidents.
A low-level investigation will involve a short investigation by the relevant supervisor or line manager into the circumstances and immediate underlying and root causes of the accident/incident, to try to prevent a recurrence and to learn any general lessons.
A medium-level investigation will involve a more detailed investigation by the relevant supervisor or line manager, the health and safety adviser and employee representatives and will look for the immediate, underlying and root causes.
A high-level investigation will involve a team-based investigation, involving supervisors or line managers, health and safety advisers and employee representatives. It will be carried out under the supervision of senior management or directors and will look for the immediate, underlying and root causes.
the number of serious injuries and deaths has not changed. The reasons for this are suggested as:
X
u Similar injuries may have completely different causes;
X
u Some incidents have the potential for serious injury yet may only result in a minor one. For example falling off a step ladder may only cause a bruise but could be very serious;
X
u Serious injuries have different underlying causes to minor injuries. For example missing controls, poor procedures, badly designed equipment create high-risk situations that may lead to a major incident.
X
u Many injuries are musculoskeletal sprains and strains which could not have ended up as fatal injuries. Whereas falling from height often results in serious injury or death;
X
u Insurance companies may concentrate more on frequent minor injuries because serious injuries, although individually expensive, are very rare;
X
u The solutions to major injury risks may be expensive and difficult to design or effect, for example changes to aircraft controls to prevent an accident like Virgin Galactic.
It is clear that a good safety record based solely on few lost time injuries or minor accidents does not guarantee a safe workplace. Companies must systematically examine their procedures, designs, supervision and the standards implemented in the workplace to identify the potential for serious injuries and major incidents, as well as paying attention to the causes of minor injuries.
5.2.4 Which incidents/accidents should be investigated?
The types of incident which may need to be investigated and the depth of the investigation Figure 5.7 F. E. Bird’s well-known accident triangle
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their story of the events to bring it into line with a consensus view);
X
u physical conditions have had less time to change;
X
u more people are likely to be available, for example delivery drivers, contractors and visitors, who will quickly disperse following an incident, making contact very difficult;
X
u there will probably be the opportunity to take immediate action to prevent a recurrence and to demonstrate management commitment to improvement;
X
u immediate information from the person suffering the accident often proves to be most useful.
Consideration should be given to asking the person to return to site for the accident investigation if they are physically able, rather than wait for them to return to work. A second option, although not as valuable, would be to visit the injured person at home or even in hospital (with their permission) to discuss the accident.
A number of people will potentially be involved in accident or incident investigation. For most of these people this will only be necessary on very few occasions. Training guidance and help will therefore be required. Training can be provided in accident/
incident investigation in courses run on site and also in numerous off-site venues. Computer-based training courses are also available. These are intended to provide refresher training on an individual basis or complete training at office sites, for example, where it may not be feasible to provide practical training.
5.2.5 Basic incident investigation procedures
Investigations should be led by supervisors, line managers or other people with sufficient status and knowledge to make recommendations that will be respected by the organisation. The person to lead many investigations will be the Department Manager or Supervisor of the person/area involved because they:
X
u know about the situation;
X
u know most about the employees;
X
u have a personal interest in preventing further incidents/accidents affecting ‘their’ people, equipment, area, materials;
X
u can take immediate action to prevent a similar incident;
X
u can communicate most effectively with the other employees concerned;
X
u can demonstrate practical concern for employees and control over the immediate work situation.
The investigation should be carried out as soon as possible after the incident to allow the maximum amount of information to be obtained. There may be difficulties which should be considered in setting up the investigation quickly – if, for example, the victim is removed from the site of the accident, or if there is a lack of a particular expert. An immediate investigation is advantageous because:
X
u factors are fresh in the minds of witnesses;
X
u witnesses have had less time to talk (there is an almost automatic tendency for people to adjust
Potential worst injury consequences of accident/incident Likelihood of
recurrence Minor
Certain Likely Possible Unlikely Rare
Serious Major Fatal
Risk Minimal Low Medium High
Investigation level
Minimal Level
Low Level
Medium Level
High Level Figure 5.8 Appropriate levels of investigation
X
u documents including written instructions, training records, procedures, safe operating systems, risk assessments, policies, records of inspections or tests and examinations carried out;
X
u interviews (including written statements) with persons injured, witnesses, people who have carried out similar functions or examinations and tests on the equipment involved and people with specialist knowledge.
Investigation interview techniques
It must be made clear at the outset and during the course of the interview that the aim is not to apportion blame but to discover the facts and use them to prevent similar accidents or incidents in the future.
A witness should be given the opportunity to explain what happened in their own way without too much interruption and suggestion. Questions should then be asked to elicit more information. These should be of the open type, which do not suggest the answer. Questions starting with the words in Figure 5.9 are useful.
Initial action
There are a lot of things that have to be done when an incident occurs. The success of an investigation comes in the first few moments. A line manager’s initial action varies for every event. The person on the scene must be the judge of what is critical. These steps are guidelines to apply as appropriate.
X
u Take control at the scene – line managers need to take charge, directing and approving everything that is done.
X
u Ensure first-aid is provided and call for emergency services.
X
u Control potential secondary events – these events such as explosions and fire are usually more serious.
Positive actions need to be taken quickly after careful thought of the consequences.
X
u Identify sources of evidence at the scene.
X
u Preserve evidence from alteration or removal.
X
u Notify appropriate site management.
Investigation method
There are four basic elements to a sound investigation:
1. Collect facts about what has occurred.
2. Assemble, and analyse, the information obtained.
3. Compare the information with acceptable industry and company standards and legal requirements to draw conclusions.
4. Implement the findings and monitor progress.
Information should be gathered from all available sources, for example, witnesses, supervisors, physical conditions, hazard data sheets, written systems of work, training records. Photographs are invaluable aids to investigation but of course with digital photography they can be easily altered. It is a good idea to print on the time and date of the picture and be prepared to verify that it is accurate. Printing out the picture as soon as possible captures it for the records. Plans and simple sketches of the incident site are also valuable.
The amount of time spent should not, however, be disproportionate to the risk. The aim of the investigation should be to explore the situation for possible
underlying factors, in addition to the immediately obvious causes of the accident. For example, in a machinery accident it would not be sufficient to conclude that an accident occurred because a machine was inadequately guarded. It is necessary to look into the possible underlying system failure that may have occurred.
Investigations have three facets, which are particularly valuable and can be used to check against each other:
X
u direct observation of the scene, premises, workplace, relationship of components, materials and substances being used, possible reconstruction of events and injuries or condition of the person concerned;
Figure 5.9 Questions to be asked in an investigation
‘Why’ should not be used at this stage. The facts should be gathered first, with notes being taken at the end of the explanation. The investigator should then read them or give a summary back to the witness, indicating clearly that they are prepared to alter the notes, if the witness is not content with them.
If possible, indication should be given to the witness about immediate actions that will be taken to prevent a similar occurrence and that there could be further improvements depending on the outcome of the investigation.
Seeing people injured can often be very upsetting for witnesses, which should be borne in mind. This does not mean they will not be prepared to talk about what has happened. They may in fact wish to help, but
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X
u deficiencies in monitoring and measurement of work activities;
X
u quality and frequency of reviews and audits.