RIDDOR Explained
RIDDOR is the reporting law behind every accident book on every UK building site, and it owns a section of the CITB HS&E test you sit for a CSCS card. HSE is the authority and publishes the full guidance at hse.gov.uk/riddor. This is the revision version.
What RIDDOR is
RIDDOR is the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations, currently SI 2013/1471. It requires employers, and others in charge of work premises, to report and keep records of work-related fatalities and injuries, diagnosed reportable occupational diseases, and certain dangerous occurrences, so the enforcing authority can respond. Not everything goes in: a report is only required when the accident is work related and it results in a reportable injury. Work related means arising out of or in connection with work, so an accident that merely happens on work premises does not qualify by itself.
What must be reported, and by when
One row below says record rather than report. That is the row people lose the mark on.
| Incident | What you must do | Deadline or limit |
|---|---|---|
| Death from a work-related accident (not suicide) | Report | Also if death follows the injury within one year (365 days) |
| Specified injury to a worker, regulation 4 | Report | Notify by the quickest practicable means without delay, then report within 10 days (Schedule 1, Part 1) |
| Worker off work or on restricted duties over 7 days | Report | Within 15 days of the accident |
| Worker off work or on restricted duties over 3 days | Record in the accident book. No report | Keep the record 3 years |
| Non-worker taken from the scene to hospital for treatment | Report | Not if taken purely as a precaution |
| Reportable occupational disease | Report | On diagnosis, in writing for an employee |
| Dangerous occurrence listed in Schedule 2 | Report | Only the classes Schedule 2 lists |
The exam point: over 7 days, not over 3
An accident keeping a worker off work or off their normal duties for more than 7 consecutive days is reported. One that does the same for more than 3 consecutive days is only recorded. The 7 days do not include the day of the accident, and they do include weekends and rest days: RIDDOR defines consecutive days as including any that are not, or would not have been, working days. The report is due within 15 days of the accident, not 15 days from when the seven ran out.
Specified injuries
Regulation 4 lists the specified injuries that must be reported:
- fractures, other than to fingers, thumbs and toes
- amputation of an arm, hand, finger, thumb, leg, foot or toe
- any injury likely to cause permanent blinding or reduced sight in one or both eyes
- any crush injury to head or torso damaging the brain or internal organs in the chest or abdomen
- serious burns, scalding included, covering more than 10% of the body or significantly damaging eyes, respiratory system or vital organs
- any scalping requiring hospital treatment
- any loss of consciousness caused by head injury or asphyxia
- any other injury from working in an enclosed space leading to hypothermia or heat-induced illness, or requiring resuscitation or more than 24 hours in hospital
Memorise the exclusions as carefully as the list. A broken finger, thumb or toe is not a specified injury, though it is still reportable if it keeps the person off normal duties for more than 7 consecutive days.
The public, diseases and dangerous occurrences
Sites sit next to pavements and shops, so accidents to people not at work matter more in construction than in most industries. One is reportable when all three hold: it involves a work activity, it results in an injury, and the person is taken directly from the scene to hospital for treatment. Examinations and diagnostic tests, X-rays included, do not count as treatment, while a dressing, stitches, a plaster cast or surgery do. Someone taken in purely as a precaution with no apparent injury is not reportable.
Diagnosed occupational diseases are reportable too, each with its own work-exposure condition attached, so a diagnosis alone is not the trigger. The listed ones likeliest to reach a construction worker are hand-arm vibration syndrome, carpal tunnel syndrome, occupational dermatitis, occupational asthma, tendonitis or tenosynovitis of the hand or forearm, and cramp of the hand or forearm. Several trace back to the substances behind the COSHH hazard symbols. Occupational cancers are reportable where an established causal link exists, HSE's examples being mesothelioma or lung cancer after exposure to asbestos fibres, and nasal cavity or sinus cancer after exposure to wood dust.
A dangerous occurrence is an event arising out of or in connection with work that could risk harm to others, the scaffold collapse being the example people reach for. HSE says plainly that not all such events need reporting: the reportable classes sit in Schedule 2, split into six Parts by workplace type.
Who reports, and what gets written down instead
Reports come from the responsible person: employers in relation to their workers, some self-employed people, and those in control of the premises where a reportable event happened. If you are the injured person you do not report unless you are self-employed, and neither does a member of the public, though anyone can raise a concern with HSE by a separate route. Telling your supervisor and letting them report is part of your general responsibilities on site. Fatal accidents and specified injuries can be reported by phone on 0345 300 9923; everything else goes through HSE's online forms.
The accident book is a different piece of law: the duty comes from social security legislation, not RIDDOR. Under regulation 25(3) of the Social Security (Claims and Payments) Regulations 1979, an employer normally employing 10 or more people at the same time on or about the same premises must keep an accessible means, in a book or electronically, of recording the particulars of an accident causing personal injury, and must preserve each record for at least 3 years. Keeping it is part of site health and welfare.
A caution about that threshold
HSE's first aid guidance phrases the same duty as applying to employers with “more than 10 employees”. The statutory instrument says “10 or more”, and the statutory instrument governs. It is a one-employer difference no test will ask you about, but a standing reminder that guidance from a regulator is not the law it describes. Where a threshold matters, read the regulation.
Practise the accident reporting questions
Accident reporting is one of the shorter sections of the Operatives paper, which makes each question expensive. Work through the accident reporting and RIDDOR questions with explanations, then noise and vibration, since hand-arm vibration syndrome is a reportable disease as well as a health risk, and the 5 steps of risk assessment that should have stopped the accident. Then sit a free CSCS practice test against the clock, or browse every practice topic.
RIDDOR: common questions
- What does RIDDOR stand for?
- The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations. HSE describes it as the law requiring employers, and other people in charge of work premises, to report and keep records of work-related fatalities, work-related injuries, diagnosed cases of reportable occupational diseases and certain dangerous occurrences.
- What is the over-7-day rule?
- A work-related accident is reportable when it leaves a worker away from work, or unable to do their normal duties, for more than 7 consecutive days. The 7 days do not include the day of the accident but do include weekends and rest days. The report must be made within 15 days of the accident.
- What is the difference between over-3-day and over-7-day?
- Over 3 consecutive days is recorded, over 7 consecutive days is reported. For an over-3-day accident the employer makes no RIDDOR report at all: recording it in the accident book under social security law is enough. This is the detail people most often get wrong.
- Who has to make a RIDDOR report?
- Only the responsible person, which HSE gives as employers in relation to their workers, some self-employed people, and those in control of work premises where a reportable accident or event happened. An injured person does not report unless they are self-employed, and nor does a member of the public. They can raise a concern with HSE instead.
- Is an accident to a member of the public reportable?
- Yes, if it involves a work activity, results in an injury, and the person is taken directly from the scene to hospital for treatment of that injury. Examinations and diagnostic tests such as X-rays do not count as treatment. A dressing, stitches, a plaster cast or surgery do. Someone taken to hospital purely as a precaution with no apparent injury is not reportable.
- Do all dangerous occurrences have to be reported?
- No. A dangerous occurrence is an event arising out of or in connection with work that could risk harm to others, and HSE states that not all of these events need to be reported. The reportable classes are listed in Schedule 2 of RIDDOR, which is split into six Parts by workplace type, so check the schedule rather than assuming.
Sources checked August 2026. Reportable injuries, the over-7-day and over-3-day rules, the 15-day deadline, non-worker accidents, occupational diseases and dangerous occurrences verified against hse.gov.uk/riddor/types-of-reportable-incidents.htm (updated 21 May 2026); the definition of RIDDOR and the responsible person against hse.gov.uk/riddor/key-definitions.htm; reporting routes and the phone number against the how-to-make-riddor-report page under hse.gov.uk/riddor/reporting/; consecutive days, diagnosis and the reporting procedure against regulations 2, 3 and 4 of SI 2013/1471 on legislation.gov.uk; and the accident book duty, the “10 or more” threshold and the 3-year retention period against regulation 25(3) of SI 1979/628. HSE enforces RIDDOR and its guidance is where to go for practical detail, but where guidance and a statutory instrument disagree, as they do on the accident book threshold above, the instrument governs.