Ebulletin correction Yesterday (6 May 2025), HSE issued a short ebulletin following our recent Work Right campaign ebulletin â both stating that respirable crystalline silica (RCS) can cause occupational asthma. This information is incorrect â RCS can cause silicosis, lung cancer and chronic obstructive pulmonary disease, but not occupational asthma. Occupational asthma is an allergic reaction that can occur in some people when they are exposed to substances, for example flour or wood dust in the workplace. For more information on occupational asthma, visit our webpage: Asthma - an overview | 
