Predictive assessment of the hygienic risk from ethanol vapors in creatine crystallization using liquid-vapor equilibrium

Abstract

Introduction: Global growth in the dietary supplements sector has driven the industrial production of creatine powder. However, its synthesis and subsequent crystallization using organic solvents, such as ethanol, generate chemical risks that must be coordinated with occupational risk prevention to avoid irreversible consequences for workers’ health.

Method: The hygienic risk from ethanol vapors was quantitatively evaluated in a 2,000 L industrial crystallizer (with 400 L allocated to the gas phase) inside a 500 m3 room. Using ChemCad software and Raoult’s Law modified with the NRTL model (mean activity coefficient of 1.2), the liquid-vapor equilibrium of the water/ethanol binary system (90-95% molar fraction) was calculated across 9 thermal stages (20 °C to 60 °C). The values were compared against the Short-Term Exposure Limit (STEL/VLA-EC) of 1,000 mg/L.

Results: The heating and maintenance phases at 60 °C recorded the highest vapor generation in the chamber, reaching theoretical concentrations of 1,283.3 mg/L and 1,325.2 mg/L respectively, which represents an unacceptable risk of 128% and 133% relative to the limit value. In contrast, during opening and discharge (20-25 °C), the hygienic risk in the room dropped drastically to an acceptable 0.01%.

Conclusions: It is concluded that opening or stopping the crystallizer at high temperatures (60 °C) poses an imminent and intolerable hygienic risk, whereas operating the equipment during the cooling and final maturation phases ensures a safe working environment.