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What Does Dehydration Mean?

Dehydration is a physiological term that describes a deficit of total body water—the amount of water that is contained within the body’s tissues—as well as the accompanying disruption to metabolic processes because of that deficit. It is caused by situations in which a person takes in less water than he or she loses, usually due to disease/illness, exposure to high temperatures, or exercise/physical activity.

Within occupational contexts, dehydration is typically caused by excess heat exposure, either due to exposure to ambient heat (temperature) or heat created through physical exercise. In addition to the illnesses directly caused by insufficient total body water, dehydration also reduces the body’s ability to cool itself, thus increasing its susceptibility to heat-related illnesses such as heatstroke.

Safeopedia Explains Dehydration

The dangers of dehydration in occupational health settings are most clearly seen in statistics related to environmental heat exposure (heat stress). According to U.S. Bureau of Labor Statistics data, heat stress resulted in 2,380 nonfatal injuries and 33 fatalities in 2015. With dehydration widely recognized as a common contributing factor to heat-stress injury and death, OSHA and other OHS authorities recommend that workers frequently drink small quantities of water to reduce their risk.

Furthermore, because dehydration disrupts human metabolic activity, it can impair workers’ cognitive and physical functions to an extent that increases their risk of an accident. An individual with 1% water deficit experiences reduced cognitive function, and workers in hot industrial environments can sweat out more than 3% of their body's water content within an hour. At a 3% water deficit, human reaction time slows to the equivalent of an individual with a 0.08 blood alcohol content (BAC).

Employers’ legally enforced general duty to provide employees with a safe workplace includes a need to prevent harm due to dehydration. In workplaces or work situations where dehydration is a reasonable concern, steps needed to comply with this duty include encouraging employees to stay hydrated, educating employees about symptoms related to dehydration, and reacting promptly to any symptoms of dehydration exhibited by an employee. Some workplaces also prevent dehydration by conducting spot hydration tests and issuing temporary stop-work orders to any worker whose hydration levels fall below a certain minimum limit.


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