Teaching Coherent Chemical Hazard Reasoning with a Pathway-Based RAMP Safety Module: Sodium Azide as a Scalable Anchor Case

Abstract Chemical safety instruction often presents laboratory hazards as static properties communicated through Safety Data Sheets (SDS) and hazard labels. This framing can lead students to apply the Recognize-Assess-Minimize-Prepare (RAMP) framework as a procedural checklist, limiting its use as a tool for causal reasoning. This article presents a single-case, scalable safety module that uses sodium azide (NaN3) as an anchor case for pathway-based RAMP reasoning. In this context, scalability means that the module can be adapted across undergraduate and graduate settings by adjusting the pace, emphasis, and expected depth of hazard reasoning. NaN3 was selected because its SDS classifications differ sharply between solid and dilute forms. Although acute toxicity warnings diminish upon dilution, reactivity hazards may still emerge through acidification, contact with metal-containing materials or residues, and confinement. This discrepancy prompted students to reconsider SDS-based safety judgments and to reason about hazard behavior through explicit chemical pathways. The module aligns RAMP instruction with the logic of Process Hazard Analysis (PHA) by asking how hazards may emerge when chemical conditions, materials, or procedures change. Undergraduate use emphasizes foundational hazard recognition and exposure-based risk assessment, whereas graduate-level use emphasizes what-if reasoning, SOP-oriented controls, and transfer to other reactive systems. Overall, this work illustrates how a focused anchor case can move safety education beyond checklist compliance and support coherent, pathway-based hazard reasoning for chemical systems in which risk emerges from reactivity and under changing laboratory conditions.