Employment law

Workplace accidents: the three conditions

10 September 2026

The Social Security Code defines a workplace accident in one sentence: a workplace accident is any accident, whatever its cause, occurring by reason of or on the occasion of work.

This very broad definition breaks down in practice into three cumulative conditions. Meeting them does not merely place the event in a category: it triggers a presumption that shifts the entire burden of proof. Social Security Code, Article 62 (French).

1. First condition: connection to work

The accident must occur by reason of or on the occasion of work. In practice this covers accidents at the time and place of work, but also those occurring at a site where the employee was sent on assignment, or during a business trip.

The word "occasion" widens the scope considerably. The accident need not occur during the task itself: it is enough that it relates to the professional activity. An accident on the premises during a break, a movement between two workshops, or an intervention outside usual hours at the employer's request all fall within this.

And "whatever its cause" rules out at the outset an argument frequently heard: the victim's clumsiness or carelessness does not remove the characterisation.

2. Second condition: suddenness

The event must be sudden, that is, capable of being located in time. This criterion separates an accident from an occupational disease:

Workplace accidentOccupational disease
OccurrenceA sudden, datable eventProgressive harm through exposure
What must be establishedThe accidental event and its dateExposure to the risk and listing in the applicable schedule
ExampleA fall, an impact, a burnA condition developed through repeated exposure

In practice this means an accident file must always carry a date and a time. Pain that appeared "gradually over recent weeks" follows a different logic.

3. Third condition: bodily injury

There must be an injury, whatever its gravity, a superficial cut suffices, and a causal link between the accident and that injury.

Two practical consequences. Apparent minor severity is never a reason not to report: a slight injury may develop, and it is the initial report that will connect that development to the accident. And medical assessment must follow quickly: the wider the gap between the accident and the first examination, the more debatable the link becomes.

4. What follows from meeting the three conditions

Where the three conditions are met, the accident and the resulting injuries are presumed to be work-related. This is a powerful mechanism, and its reach is worth measuring:

Without the presumptionWith the presumption
The employee would have to prove the link between their condition and their workThe link is presumed: nothing further to demonstrate
Doubt would work against themDoubt works in their favour
Every relapse would need connectingThe presumption covers the whole period of incapacity, until full recovery or consolidation

The presumption therefore extends over time: it is not confined to the day of the accident but covers the entire period of incapacity.

5. Can the presumption be challenged?

Yes, but the demonstration is demanding. An employer challenging it must establish that the accident arises from a cause wholly unrelated to work: a strictly personal activity, the manifestation of a pre-existing condition unconnected with the work, an external event with no link.

That proof is hard to make, and experience shows it almost always rests on material gathered at the time of the events: written statements, times, location, the nature of the activity underway. A file reconstructed weeks later virtually never suffices.

One important clarification: challenging the presumption is not the same as refusing to report. The employer reports, then enters reasoned reservations. Not reporting challenges nothing: it merely closes off the investigation. See Workplace accidents: mistakes to avoid.

6. Death occurring at work

The presumption keeps its full force in the gravest situations. Including where death occurs at work in circumstances involving an act of the victim, the presumption of work-relatedness applies, and only a cause entirely independent of the working context can displace it.

This point is worth teams knowing, because it guides what to do: in such situations, reporting is required as in every other case.

7. And if the three conditions are not met?

Two routes remain open, and neither justifies inaction:

  • The commuting accident, if the event occurred on the protected journey between residence and workplace. The regime is close, but the burden of proof differs: see Commuting accident.
  • Non-occupational sick leave, if no connection is established. The contract is then suspended for up to six months, under a different regime.

Choosing between these characterisations belongs to the investigation, not to the employer. Labour Code, Article L.34 (French).

Key takeaways

The ruleWhat it implies
Three cumulative conditionsConnection to work, suddenness, bodily injury
"Whatever its cause"The victim's carelessness does not remove the characterisation
"On the occasion of work"Assignments, travel and breaks fall within scope
An accident is dated, a disease is exposureSuddenness is what separates them
The presumption covers the whole incapacityUntil full recovery or consolidation
Challenging is not abstaining from reportingReport first, then enter reasoned reservations