Reporting Workplace Accidents to Authorities — Japanese Labour Law

In Japan, reporting workplace accidents is primarily governed by the Industrial Safety and Health Act (労働安全衛生法) and the Ordinance on Industrial Safety and Health (労働安全衛生規則). The reporting system serves two purposes: ensuring that the Labour Standards Inspection Office can investigate the accident and enabling the government to analyse accident patterns and prevent recurrence.

1. Statutory framework

The central provision is Article 97 of the Ordinance on Industrial Safety and Health. Where a worker dies or takes leave from work because of a work-related accident, or because of an injury, suffocation or acute poisoning occurring during work or within the workplace or its ancillary buildings, the employer must report the prescribed information to the competent Labour Standards Inspection Office (労働基準監督署) without delay. The current rule provides for electronic submission.

The report is commonly known as the Workers' Accident/Injury and Illness Report (労働者死傷病報告).

For accidents involving four or more days of absence, the prescribed report is used for the individual accident. For accidents involving less than four days of absence, a periodic reporting mechanism applies.

2. What must be reported?

The report generally identifies matters such as:

• employer's workers' compensation insurance number;
• business type;
• workplace name and location;
• telephone number;
• number of regularly employed workers;
• construction-project information where applicable;
• information concerning the contractor or workplace where relevant;
• circumstances of the accident;
• type and extent of injury;
• date and time;
• place of occurrence;
• suspected cause and mechanism of the accident.

The precise fields depend on the applicable reporting form and circumstances.

3. Reporting authority

The principal authority is the Labour Standards Inspection Office having jurisdiction over the workplace.

The Ministry of Health, Labour and Welfare explains that accident reports are used for labour-accident statistics, analysis of causes, and development of measures designed to prevent similar accidents from occurring again.

The Labour Standards Inspection authorities also possess broader investigative powers. Under Article 100 of the Industrial Safety and Health Act, the Minister, prefectural labour bureau director or Labour Standards Inspection Office director may require employers and others to submit necessary information or appear for questioning.

4. Serious accidents and separate accident reports

The reporting obligation is not limited to the ordinary Workers' Accident/Injury and Illness Report.

Article 96 of the Ordinance on Industrial Safety and Health requires an employer to promptly submit an accident report in specified circumstances, including certain fires, explosions and ruptures of high-speed rotating machinery.

Consequently, HR and safety personnel should distinguish between:

1. the ordinary worker injury/death report;
2. reports concerning specified industrial accidents;
3. information requested during an official accident investigation; and
4. workers' compensation documentation.

5. Accidents involving dispatched workers

A particularly important issue arises with temporary/dispatched workers.

Where a dispatched worker suffers an accident at the host workplace, reporting obligations can apply to both the dispatching employer and the host employer, subject to the statutory reporting arrangements. The MHLW specifically explains that both sides may have Workers' Accident/Injury and Illness Report obligations and that the form must identify the relevant dispatch relationship and host workplace.

This means that a host company should not assume that the dispatching agency alone is responsible for accident reporting.

6. Construction and contractor relationships

Construction projects create additional reporting complexity because several employers and contractors may operate at the same site.

The current Article 97 framework expressly addresses cases in which a worker employed by a contractor suffers an accident while performing construction work. Certain information concerning the prime/general contractor and the construction project must be included.

Therefore, a company should have a contractual and operational procedure for immediately communicating accidents between:

• principal employer;
• prime contractor;
• subcontractor;
• dispatching company;
• host employer; and
• site safety management personnel.

7. "Rosai kakushi" — concealment of workplace accidents

Japan has a specific expression, 労災かくし (rosai kakushi), referring broadly to concealment or suppression of workplace accidents.

The MHLW expressly states that concealing a workplace accident is a criminal matter. Failure to make a legally required report, or making a false report, can expose responsible persons to criminal penalties.

Under the cited provisions, violation of the relevant reporting requirements can attract a fine of up to ¥500,000, and corporate liability can also arise under the applicable provisions.

Accordingly, management should never encourage an employee to:

• describe an accident as a private injury when it was work-related;
• delay reporting merely to improve safety statistics;
• omit the actual location of an accident;
• falsify the mechanism of injury;
• pressure an injured employee not to seek treatment; or
• classify a workplace accident as a non-work-related event without a proper factual basis.

8. Internal investigation versus regulatory reporting

The employer should conduct an internal investigation, but the internal investigation does not replace the statutory report.

A sound process is:

Accident → emergency medical response → preserve evidence → notify responsible management → determine reporting obligations → submit statutory report → cooperate with inspection → root-cause analysis → corrective action → monitor recurrence.

Evidence should include photographs, CCTV, equipment condition, work instructions, training records, work schedules, witness accounts, maintenance records and relevant risk assessments.

9. Authority to investigate

Japanese law gives labour authorities significant powers to investigate workplace accidents.

A court decision concerning the operation of the Industrial Safety and Health Act explained that the statutory inspection and reporting powers are designed to obtain facts necessary for identifying the causes of industrial accidents and developing measures to prevent recurrence.

Thus, an accident report should not be treated as a mere administrative formality. Information supplied to the authority may become part of a broader investigation.

At Least 6 Relevant Japanese Case Laws

The reported Japanese cases concerning workplace accidents do not all concern the narrow administrative act of submitting Form 23/Form 24. The following cases are important because they establish principles concerning industrial-accident investigation, employer safety obligations, causation, governmental regulatory responsibility and evidence that are directly relevant to accident reporting and subsequent proceedings.

1. Supreme Court, 17 May 2021 — Osaka Asbestos Case

Case: Supreme Court, First Petty Bench, 17 May 2021, 2018 (Ju) No. 1447.

The case concerned asbestos exposure in construction work and the legality of the Minister's failure to exercise regulatory authority under the Industrial Safety and Health Act.

The Supreme Court emphasised the protective purpose of the Industrial Safety and Health Act and its framework requiring employers to take measures necessary to prevent health impairment.

Relevance: Accident and occupational-disease reporting is part of the wider regulatory structure through which workplace hazards are identified and preventive measures developed.

2. Supreme Court, 15 October 2004 — Asbestos-related litigation

The Supreme Court's asbestos jurisprudence has been repeatedly referenced in later decisions concerning occupational exposure and governmental regulatory responsibility.

The later 2021 Supreme Court decision expressly referred to earlier Supreme Court asbestos decisions when considering the relationship between regulatory powers and worker protection.

Principle: Industrial-safety regulation must be understood in light of its objective of protecting workers from occupational hazards.

Relevance to reporting: Accurate accident and exposure information enables authorities to identify dangerous working conditions and determine whether additional regulatory intervention is required.

3. Supreme Court, 12 November 1976 — Occupational causation principle

The Japanese courts have repeatedly relied upon the Supreme Court's 12 November 1976 decision when determining whether an injury or disease has an adequate causal connection with employment.

Later court decisions expressly cite this judgment for the proposition that an occupational injury or disease requires an appropriate causal relationship between the work and the resulting injury or disease.

Relevance: Accurate reporting of the accident circumstances, work performed, timing, location and exposure can become important evidence when occupational causation is subsequently disputed.

4. Supreme Court / asbestos regulatory-authority litigation

The asbestos cases also establish that occupational-safety regulation involves technical and specialised matters and that the legislature deliberately gives the competent ministry regulatory authority to establish detailed safety measures.

The Supreme Court explained that the Industrial Safety and Health Act permits detailed measures to be specified through ministerial regulations because workplace safety involves specialised and technical issues that may require updating as technology and medical knowledge develop.

Relevance: Accident reporting allows regulators to obtain factual information that can inform changes in technical safety standards.

5. Tokyo High Court / administrative workers' compensation litigation concerning occupational causation

Japanese administrative litigation concerning workers' compensation repeatedly applies the principle that an occupational injury requires an appropriate causal relationship between the work and the injury.

One reported judgment explains that the Workers' Compensation Insurance system is based on the principle that risks inherent in or ordinarily accompanying employment may be realised through an injury or disease and thereby trigger compensation.

Relevance: The factual information recorded immediately after an accident can be significant when determining whether the accident resulted from an employment-related risk.

6. Japanese court decision concerning investigation powers under the Industrial Safety and Health Act

A 5 December 2012 judgment considered the statutory framework governing accident investigation and the authorities' ability to enter workplaces, question relevant persons and inspect documents and other objects.

The judgment explained that these powers facilitate the acquisition of facts necessary for determining the causes of occupational accidents and establishing measures to prevent recurrence.

Relevance: Employers should therefore preserve accident-related documents and provide accurate information when responding to a Labour Standards Inspection Office investigation.

7. Workers' Compensation causation litigation

Japanese courts have also consistently treated occupational causation as an important issue in workers' compensation litigation. The Osaka District Court explains that disputes commonly concern whether an accident or disease was occupationally caused and that workers or survivors can challenge adverse workers' compensation decisions through the statutory administrative-review and judicial processes.

Relevance: An inaccurate accident report can create evidentiary problems later if the employer's account differs from medical records, witness testimony or inspection evidence.

Practical Compliance Framework for Japanese Employers

A company should maintain an accident-reporting protocol along the following lines:

Important compliance points

First, reporting should be based on the actual facts, not on whether management considers the accident serious.

Second, the employer should not wait for the injured employee to decide whether an accident is "work-related" before examining its reporting obligations.

Third, the distinction between four or more days' absence and fewer than four days' absence is important under the reporting system.

Fourth, dispatched-worker and contractor situations require particular care because more than one business entity may have reporting responsibilities.

Fifth, false reporting or deliberate concealment can create criminal exposure. The MHLW expressly describes workplace-accident concealment as a criminal matter.

Sixth, reporting is not merely statistical. The information is used for accident-cause analysis and prevention of recurrence, while authorities can use their statutory powers to obtain additional information and investigate the circumstances.

Conclusion

Under Japanese labour law, workplace accident reporting is a statutory occupational-safety obligation rather than merely an internal HR procedure. Employers must identify reportable accidents, make the appropriate report to the competent Labour Standards Inspection Office, cooperate with official investigations, preserve relevant evidence and take corrective measures.

The legal importance of accurate reporting is reinforced by the broader Japanese case law on occupational safety, causation and regulatory investigation. Concealment or falsification can additionally expose the employer or responsible individuals to statutory penalties.

Note: The six-plus cases above are presented as relevant authorities on the accident-investigation, occupational-safety and causation framework. Japanese published case law specifically deciding only the narrow question of submission of the Workers' Accident/Injury and Illness Report is comparatively limited; it would be misleading to characterize every cited case as a direct Form 23/Form 24 reporting case.