Occupational Diseases: Recognition, Schedules, and Compensation

Occupational diseases are conditions contracted as a result of professional activity. They are listed in schedules that facilitate their recognition and compensation by social security.

An occupational disease is a condition contracted as a result of a worker's exposure to a physical, chemical, biological, or psychosocial risk during their professional activity. Unlike an occupational accident (a sudden, external event), an occupational disease results from prolonged exposure, sometimes over many years, and may manifest long after the exposure has ceased (e.g., cancers, silicosis). Its recognition and compensation are governed by a system of schedules.

Definition

For a disease to be recognized as occupational, three conditions must generally be met:

1. The disease is listed in an occupational disease schedule (or is deemed equivalent to such a schedule).
2. The worker was exposed to the corresponding risk for a minimum duration (exposure period).
3. The disease manifested within a compensation period between the end of the exposure and the first medical diagnosis.

The Schedule System

The system of occupational disease schedules was pioneered in France (the first schedule in 1919 for lead poisoning). Each schedule describes:

• The designation of the disease (clinical title).
• The indicative list of works likely to cause the condition.
• The compensation period (maximum duration between the end of the exposure and the declaration).
• The minimum duration of exposure required.

This system creates a presumption of origin: if the conditions of the schedule are met, the disease is presumed to be of occupational origin, without the worker having to prove the causal link.

Recognition Procedure

The declaration of an occupational disease follows a specific process:

1. Medical Diagnosis: The physician (occupational health, general practitioner, or specialist) issues an initial medical certificate.
2. Employer Declaration: In Morocco, the employer must declare the occupational disease within a short timeframe to the insurer (typically 5 days according to Moroccan legislation on occupational accidents and diseases governed by Law No. 18-12; verify the applicable implementing text and competent authority). The declaration is transmitted to the CNSS, which manages the review process.
3. Social Security Review: Verification of the schedule's conditions, the worker's exposure, and the compensation period. Recognition or motivated refusal.
4. Appeals Process: In case of refusal, the worker can appeal to the conciliation commission, and then to the labor court.

Main Categories of Occupational Diseases

The most frequent occupational diseases include:

• Musculoskeletal Disorders (MSDs): Low back pain, carpal tunnel syndrome, tendinitis. The leading cause of occupational diseases in most industrialized countries.
• Occupational Dermatoses: Contact eczema, irritant dermatitis (hairdressing, cleaning, construction trades).
• Occupational Hearing Loss: Noise exposure (mechanical industry, textiles, construction and public works, agriculture).
• Respiratory Diseases: Asthma, chronic obstructive pulmonary disease (COPD), silicosis, asbestosis, berylliosis.
• Occupational Cancers: Mesothelioma (asbestos), lung cancer, bladder cancer (aromatic substances), leukemias (benzene).
• Chronic Intoxications: Lead poisoning, mercury poisoning (hydrargyrism), manganism.

Compensation

In Morocco, the CNSS (Caisse Nationale de Sécurité Sociale) compensates recognized occupational diseases according to a scale that provides for:

• Coverage of medical care: Consultations, hospitalization, medication, rehabilitation.
• Payment of daily allowances in case of work stoppage.
• The award of a pension or a lump sum in cases of permanent incapacity (partial or total), calculated based on the rate of incapacity, the reference salary, and the worker's age.
• Survivors' pension in case of death.

Prevention

The prevention of occupational diseases is always preferable to compensation. It relies on:

• Elimination of the risk at the source (substitution, automation, enclosure).
• Collective protection (ventilation, source extraction).
• Individual protection (respiratory protective equipment, gloves, anti-noise protection).
• Medical surveillance (medical examinations, biological monitoring, dosimetry).
• Traceability of exposures (exposure record, asbestos exposure certificate).

Sources et références

8. Code du travail marocain (Loi n° 65-99), Titre IV — articles 281 et suivants (principes généraux de prévention) ILO NATLEX : https://natlex.ilo.org/dyn/natlex2/r/natlex/fe/details?p3_isn=67319

9. INRS — Tableaux des maladies professionnelles (base de données, URL vérifiée 24/10/2026) https://www.inrs.fr/publications/bdd/mp.html

10. INRS — Liste des tableaux de maladies professionnelles (URL vérifiée 24/10/2026) https://www.inrs.fr/publications/bdd/mp/listeTableaux.html