Non-Newtonian Fluids and Uncontrolled Emission of Toxic Gases: A Major Threat to Worker Safety

Abstract

This article explores the role of shear-thinning , pseudoplastic non-Newt onian fluids in the causation of fatal accidents involving hazardous atmospheres. Analysis of fatal accidents indicates an appreciable likelihood of occurrence in structures in the infrastructure. When subjected to a shear force, such as stirring, stored gas emits from these fluids. Depending on the gas, lethal concentrations can develop almost instantaneously. Upon cessation of the stress, the ambient condition restores rapidly. Chemical and physical processes that provide reservoirs for the storage of gases potentiate anaerobic respiration by microorganisms as the source of the gases stored in some non-Newtonian fluids. Hydrogen sulfide (H 2 S) is the most toxic gas followed by carbon dioxide (CO 2 ) and ammonia (NH 3 ). Very limited methods are available for controlling exposure to gases emitted during the disturbance of these fluids. Control strategies must accommodate almost instantaneous high-level emissions. Disturbance under controlled conditions that isolates emissions from workers is a possible means to minimize the risk of exposure. Engineering design that incorporates suitable control devices into equipment and structures is critical to the success of this strategy. The Prevention through Design program created by the U.S. National Institute for Occupational Safety and Health is a formal initiative for coordinating an organized response to these challenges .