Occupational asthma has become the leading cause of occupational respiratory disease worldwide. Its prevalence and the diversity of possible aetiological agents have increased significantly over the last twenty years. The work environment plays an important role in the development of this pathology, notably through changes in technology and the introduction of new molecules and manufacturing processes.The work environment plays an important role in the onset of asthma. As these are potentially serious pathologies, likely to pose problems for affected employees in terms of job retention, it is important to identify and prevent them.