Experimental Evaluation of a Low-Hazard Source-Level Mitigation Strategy for Indoor Formalin Spill Response in Educational Facilities

Abstract

Formalin is widely used in educational facilities for specimen preservation and laboratory experiments; however, its primary component, formaldehyde, is a volatile, toxic, and carcinogenic substance that may pose significant health risks when released indoors. This study experimentally evaluated sodium bicarbonate (NaHCO₃), urea (H₂NCONH₂), and sodium hydroxide (NaOH) as candidate materials for a low-hazard source-control strategy for formalin spill incidents in educational facilities. Qualitative bromothymol blue (BTB) indicator assessments and GC–MS analyses showed that sodium bicarbonate and sodium hydroxide substantially reduced formaldehyde-associated responses, whereas urea exhibited little observable effect under the conditions tested. In sealed-chamber experiments simulating indoor formalin spill scenarios, airborne formaldehyde concentrations increased rapidly and exceeded 800 ppm under untreated conditions. In contrast, sodium bicarbonate treatment maintained concentrations below 20 ppm throughout the experimental period and effectively suppressed concentration buildup over time. These findings suggest that sodium bicarbonate may reduce airborne formaldehyde release by altering physicochemical conditions that influence formaldehyde volatilization. Owing to its low hazard profile, favorable handling characteristics, wide availability, and operational practicality, sodium bicarbonate demonstrated considerable potential as a low-hazard source-control material capable of complementing conventional ventilation- and dilution-based Hazmat response strategies for indoor formalin spill incidents.