Background <p>Workers who handle hazardous substances are at risk of health impairments, occupational diseases and even premature death. Occupational diseases are preventable, but early detection, diagnosis and intervention remain inadequate. Therefore, we aim to gain insight into the determinants of timely identification of health effects caused by exposure to hazardous substances in the workplace as perceived by occupational health professionals.</p> Methods <p>We conducted seventeen online semi-structured interviews among Dutch occupational hygienists and occupational physicians on their perspectives and experiences in identifying chemical-related health effects in the workplace. The interviews were transcribed verbatim and the data were analysed using the Capability, Opportunity, Motivation-Behaviour (COM-B) model.</p> Results <p>Occupational hygienists and occupational physicians experience limited knowledge, skills, and self-efficacy for timely identification of chemical-related health effects. These modifiable determinants hinder effective collaboration between these occupational health professionals in translating exposure to hazardous substances into health effects and vice versa. Moreover, different system-level determinants in the Netherlands further impede this collaboration. Existing tools for occupational health professionals reinforce this gap by supporting either exposure assessment or health effect evaluation, rarely bridging the two. As a result, current tools are often tailored to a single professional group.</p> Conclusions <p>The results from our study suggest that gaps in knowledge, skills and self-efficacy hinder timely identification of chemical-related health effects in the Netherlands. The findings of this study can inform the development of multidisciplinary interventions and multifaceted strategies aimed at improving prevention of chemical-related occupational disease and timely implementation of appropriate (workplace) measures.</p>