Dangerous occurrences are certain incidents with a high potential to cause death or serious injury. Those incidents which must be reported are listed in Schedule 2 of the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR).
Reporting these occurrences:
This page explains which sections in Schedule 2 of RIDDOR apply for each type of dangerous occurrence. The relevant paragraph numbers are provided to help you find the right section of the Schedule.
Reporting dangerous occurrences does not require complex analysis. It is more about making a reasonable judgement on whether the incident caused a real risk of harm. This allows for quick reporting and ensures valuable information is not lost.
The term ‘plant’ is used throughout Schedule 2. It is defined in the Health and Safety at Work Act as including any machinery, equipment or appliance.
Paragraphs 1-23 of Schedule 2 cover reportable dangerous occurrences at all workplaces. There is a separate section on this page for incidents at all workplaces except those offshore.
The definition covers the collapse or overturning of any lifting equipment, or the failure of any load-bearing part, whether it is used for lifting goods, materials or people.
It does not cover the failure of:
Failure means components which break down mechanically during the normal operation of the lifting equipment, rather than accidental or deliberate damage.
Incidents involving cranes must be reported whatever work is being done, and reports must not be restricted to those involving lifting and lowering. For example, a collapse or overturning when a machine is being used for demolition activities must be included.
Lifting equipment includes machinery such as bored piling rigs and percussion piling rigs.
The definition in paragraph 2 of the Schedule covers the failure of a pressure system (other than a pipeline) with the potential to cause the death of any person. It applies to any such vessel, whatever its contents.
These incidents include:
Other examples of incidents which might be notifiable as having ‘potential to cause death’ would be those where a person was either struck by, or could have been struck by, a projectile emitted from the failure of a closed vessel or pipeline under pressure.
In an explosion, this might be:
Incidents involving any unintentional contact between plant or equipment and overhead electric lines are reportable when they involve:
Examples of these kinds of reportable incidents are:
Where an electrical short circuit or overload causes the failure of electrical equipment (including through accidental damage) and results in a fire or explosion, this is reportable if:
The incident is reportable even if the system in which the damaged equipment was installed is put back into service, using new equipment, within 24 hours. An assessment should be made of how long a repair to the damaged equipment would have taken.
Repair time does not include incidental time delays, for example caused by travelling to repair plant in remote locations, or with sourcing parts.
For fires and explosion that do not relate to electrical incidents, please refer to paragraph 25 of the Schedule.
The types of incidents that must be reported involving explosives are covered in paragraphs 5-9 of the Schedule.
These dangerous occurrences refer to:
You must report any accident or incident which results, or could have resulted, in the release or escape of a biological agent likely to cause severe human infection or illness.
A ‘severe human infection or illness’ is one caused by biological agents in Hazard Groups 3 and 4 as defined in Schedule 3 of the Control of Substances Hazardous to Health Regulations (COSHH).
You must report any malfunction of:
'Radiation generator' means any electrical equipment emitting ionising radiation and containing components operating at a potential difference of more than 5kV.
The processes covered include all types of industrial radiography – such as radiography in fixed enclosures, site radiography, and radiography in closed cabinets.
Irradiating and processing products by irradiation are high-dose treatments and this covers panoramic systems as well as self-contained units. In each case, it is the failure of the means for de-energising the radiation generator at the end of the intended exposure period that constitutes the dangerous occurrence.
Incidents where equipment malfunction causes a radioactive source to fail to return to a safe (shielded) position at the end of the intended exposure period are also reportable. The sources will commonly be gamma ray sources, but in industrial radiography they could be beta ray or neutron sources.
The processes covered include all types of industrial radiography, and use of gamma irradiation equipment (panoramic or self-contained). The type of equipment must mean:
Any malfunction affecting the equipment and its control system causing the failure of the source to return to this state at the end of the intended exposure period constitutes a dangerous occurrence.
These incidents must be reported whether or not anyone is exposed to ionising radiation as a result of the incident occurring, other than those incidents which must be reported under the Ionising Radiations Regulations (IRR).
Where a report is required under IRR, there is no need to also report under RIDDOR, except in relation to offshore workplaces.
You must report the malfunction of breathing apparatus:
This definition applies to breathing apparatus used under water as well as in contaminated atmospheres or where there may be a lack of oxygen. It refers to a session of use of the apparatus during, or immediately before, a malfunction is detected.
The malfunction may be present and be detected immediately before the session (including any testing by the wearer immediately before use), or it may occur at some point after the session has started.
The term 'malfunction' does not include leakage into a face mask due to a poor fit or a failure caused by an external source, such as damage due to entanglement or falling debris.
You must report the failure, damaging or endangering of:
which causes a significant risk of personal injury to a diver.
You must also report:
Specialist advice is available from HSE diving inspectors by e-mail at [email protected] .
You must report the complete or partial collapse (including falling, buckling, or overturning) of:
The incidents covered here are those involving any 'scaffold'. This includes any tower, trestle, slung or suspended scaffold.
The figure of 5 metres refers to the height of the scaffolding itself from its base and not necessarily to the distance between the top of the scaffold and the ground.
Incidents involving the failure of the suspension arrangements of slung or suspended scaffolds are covered if the failure causes a working platform or cradle to fall.
Reportable failures of suspension arrangements would include failures of outriggers, roof rigs or suspension ropes or winches.
You must report the collision of a train with any other train or vehicle, other than a collision reportable under Part 5 of the Schedule, which could have caused the death, or specified injury, of any person.
RIDDOR therefore only applies to collisions between rail-mounted locomotives or trains and other vehicles within factory or dock premises, or at construction sites, mines or quarries.
Part 5 of the Schedule refers to 'relevant transport systems', which are covered by paragraphs 48-74. Those type of incidents are reportable to the Office of Rail and Road (ORR).
The incidents listed in the Schedule are reportable for all wells, both onshore and offshore, that are drilled for the exploration or exploitation of oil or gas. This includes production of coal bed methane for commercial purposes.
They also apply to wells drilled in connection with the exploitation of oil or gas, for example those used to support reservoir pressure through water or gas injection.
Reports are required for:
Reports are not required where:
You should report failures of the primary pressure containment envelope of a well or of safety devices, namely blowout preventers or surface, subsea and subsurface safety valves, where there is a major loss of pressure integrity requiring immediate remedial action.
It is not necessary to report minor leaks or failures found and rectified during routine maintenance, including replacement of worn components. However, significant leakages around a well of hydrocarbon gas from shallow formations should be reported.
All unplanned well intersections, where a well is unintentionally drilled into an existing one, are reportable. 'Near misses' should also be reported if normal drilling operations have to be interrupted to take remedial action to reduce the risk of collision.
The detection of hydrogen sulphide at a well, or in samples of well fluids where the well operator did not anticipate its presence in the reservoir drawn on by the well, should be reported.
The incidents listed in the Schedule are reportable for both onshore and offshore pipelines or pipeline works.
The phrase 'accidental or uncontrolled release' used in the Schedule is not intended to include minor leaks from pipelines, for example small leaks from valve stems, flanges etc. However, sudden or uncontrolled escapes requiring immediate attention or action should be reported.
Examples of reportable damage with the potential for harm would include gouging, denting, buckling etc caused by external interference requiring immediate action. Such damage may or may not have resulted in any escape of the pipeline contents.
Shutdown following discovery of substantial internal or external corrosion, so it would not be safe to continue operating the pipeline, should also be reported.
External coating damage without damage to the underlying substrate would not be reportable.
Examples of reportable occurrences would include movement of offshore pipelines following development of critical 'spans' and subsequent instability or displacement due to wave action or boat impact.
Occurrences that are not reportable include:
The following types of pipeline are not covered by these requirements as provided by a RIDDOR Exemption Certificate:
Paragraphs 23-27 of Schedule 2 cover incidents you must report unless you are working at an offshore workplace. There is a separate section on this page for incidents at offshore workplaces.
Only structural collapses associated with ongoing construction, maintenance and demolition work are required to be reported under the definition in paragraph 23: ‘the unintentional collapse or partial collapse of:
However, the requirement in paragraph 24 to report ‘unintentional collapses of partial collapse of any falsework’ applies whether construction work is taking place or not.
'Falsework' means any temporary structure used to support a permanent structure during its erection and until that structure becomes self-supporting.
This dangerous occurrence covers fires and explosions at work premises. The plant referred to includes any machinery, equipment or appliance.
Examples of the type of incident which would be reportable are:
The incident is not reportable if either the plant or the work activity in those premises where the fire or explosion occurred has not resulted in a stoppage or a suspension of normal work for more than 24 hours.
This covers releases of flammable liquids or gases (for example due to the sudden failure of a storage vessel) where the release, if ignited, would cause a major explosion or fire.
'Flammable' includes those substances classified as highly flammable or extremely flammable.
If you are the responsible person, you should make a reasonable judgement about the quantity of flammable liquid or gas released.
Detailed calculations are not required, but where it is probable that the quantities released are within the categories set out in paragraph 26, you should make a report.
This dangerous occurrence only applies to the hazardous escape of substances in the workplace.
Failing to contain substances on a vehicle is only reportable if the failure occurs while the vehicle is at a workplace (for example during loading or unloading).
There is legislation which covers hazardous substances being transported. HSE has produced guidance on the carriage of dangerous goods.
The substances covered by this dangerous occurrence may be in any form such as a liquid, solid (for example a powder), gas or vapour. This may include:
Examples of the kinds of incident covered are:
You are not required to report releases from plant etc when they are controlled enough to ensure no one is at risk during normal operation or maintenance. Examples include during sampling, packaging or draining of lines.
In some cases, deciding whether an incident is reportable will be straightforward. For example, you must report a person being exposed to a hazardous substance which exceeds established safe limits, such as a workplace exposure limit.
However, most incidents require more judgement. Factors you could consider include:
Paragraphs 28-46 of Schedule 2 cover the following types of incidents in mines:
HSE mines inspectors can give specialist advice on dangerous occurrences reportable in mines.
If you have a concern in relation to health and safety at a mine you can tell HSE about the issue directly.
Paragraphs 47-53 of Schedule 2 cover the following types of incidents in quarries:
HSE quarries inspectors can give specialist advice on dangerous occurrences reportable in quarries.
If you have a concern in relation to health and safety at a quarry you can tell HSE about the issue directly.
Paragraphs 54-74 of Schedule 2 cover incidents on relevant transport systems.
A relevant transport system is:
These incidents are reportable to the Office of Rail and Road (ORR), who publish their own ORR guidance on RIDDOR.
Paragraphs 75-87 of the Schedule cover the dangerous occurrences that are only reportable if they occur at an offshore workplace. This is defined in regulation 2 of RIDDOR and includes:
Offshore windfarms and other renewable energy installations are not included.
Some incidents only apply at offshore installations. In this section 'offshore installation' includes subsea units, but excludes:
There is separate guidance on reporting incidents (under Schedule 2) at:
To report on an offshore-related issue please use the Report of an Oil and Gas Incident (ROGI) form.
The form allows reporting under all the relevant legislation and requirements including RIDDOR.
Specialist advice on reporting requirements offshore is available.
This section of the Schedule only refers to confirmed, unintentional releases of petroleum hydrocarbons. Suspected releases which turn out to be false alarms are not reportable.
To be reportable, releases must also lead to one of the following outcomes:
You do not need to report small gas leaks detected during routine monitoring and maintenance, for example checking on valves, seals etc where there is limited risk to people. To be reportable, the action must intend to prevent or limit the consequences of a potential fire or explosion.
Simply taking action to confirm a release following an alarm, for example by instrument reading that requires no further action, would not be reportable. However, taking action to confirm a release may precede more direct, reportable action.
Examples of actions when the release is reportable are:
Hydrocarbon releases which are not covered above, but are also reportable are:
Any fire or explosion at an offshore installation, other than one caused by the release of petroleum hydrocarbon, is reportable when it results in stopping plant or suspending normal work.
This covers fires or explosions, such as:
Unintentional or uncontrolled release or escape of any substance on or from an offshore installation is reportable when it could cause a significant risk of personal injury. This does not include release of petroleum hydrocarbon.
Releases of substances such as stored chemicals, superheated steam, or H2S are reportable where they don’t involve hydrocarbons.
Any unintentional collapse or partial collapse of any offshore installation or of any plant on an offshore installation is reportable when it jeopardises the overall structural integrity of the installation.
The failure of equipment required to maintain a floating offshore installation on station is reportable when it could cause a specified injury or the death of any person.
Dropping any object on an offshore installation or on an attendant vessel or into the water adjacent to an installation or vessel is reportable when it could cause a specified injury or the death of any person.
Any damage to or on an offshore installation caused by adverse weather conditions is reportable when it could cause a specified injury or the death of any person.
Any collision between a vessel or aircraft and an offshore installation is reportable when it causes damage to the installation, the vessel or the aircraft.
Any occurrence with the potential for a collision between a vessel and an offshore installation is reportable where, had a collision occurred, it might have jeopardised the overall structural integrity of the installation.
It will not always be possible to accurately estimate whether a collision could have occurred or what the consequences might have been. HSE mainly wants to know about incidents where the dutyholder identifies a significant risk to the installation.
Any subsidence or collapse of the seabed likely to affect the foundations or the overall structural integrity of an offshore installation is reportable.
Any incident which causes the loss of stability or buoyancy of a floating offshore installation is reportable.
Any partial or complete evacuation of an offshore installation is reportable when in the interests of safety.
Do not report a complete or partial evacuation if it is a response to an incident that is reportable separately under RIDDOR (such as a fire or explosion).
This definition does not cover exercises or precautionary measures.
Any person falling into water from more than 2 metres is reportable.