Inherently safer design: An accident prevention perspective on reported confined space fatalities in Quebec

The design of most industrial facilities incorporates confined spaces. Although they are not designed for human occupation, many workers penetrate them to perform tasks such as repairs, cleaning, and inspections while facing the risks of asphyxiation, drowning, and toxicity from chemical exposure. Legislative and normative frameworks recommend adopting Inherently Safer Design (ISD) principles as the primary accident prevention strategy However, confined space fatalities occur mainly during improvised interventions, emphasizing the need for designers to consider these accidents' underlying factors in their future or present projects. This paper provides an applied perspective, suggesting how practitioners can employ ISD principles to effectively overcome the inherent design deficiencies and hazards associated with confined space fatalities. For this purpose, ten confined space fatalities in six different sectors of activity were analyzed using the Causal Tree Method (CTM). Industrial process cases are included. Our results show that alternative safer designs of confined spaces or permanent adapted equipment could eliminate the need for a confined space entry or confined space work. A first model of a design-oriented solutions knowledge base, called Confined Space Permanent Collective Principles (CSPCP), is proposed. This model provides stakeholders from across various industries with an overview of safety measures that can be integrated at different life cycle phases to address confined space hazards.