OCH&S

How to manage dehydration in the workplace

There are a variety of occupational situations where workers are exposed to a hot climate, and may also be engaged in moderate to heavy physical activity. Under these conditions, workers are vulnerable to dehydration.

Occupations that fall into this category include:

  • Mining, mineral and oil exploration and processing
  • Steel production and foundries
  • Building and construction
  • Road and rail works
  • Forestry
  • Farming, agriculture and horticulture
  • Military operations
  • Fire-fighting
  • Manufacturing
  • Transport
  • Council and parks work

Rates of fluid loss, as sweat, in these occupations vary considerably, depending on such factors as workplace temperature, sun exposure, work clothing, activity intensity and duration.

For example:
Australian rural fire fighters suppressing bushfires were found to generate sweat at a rate of 1 – 2 L/h. (ref. 1)

A study of US military personnel demonstrated sweat loss in the range of about 0.2 – 1.5 L/h, depending on activity (ref. 2)

Fluid and electrolytes lost through perspiration can lead to dehydration. At greater than 2% loss in body mass, physical and mental performance may diminish.

Be aware of the signs of mild to moderate dehydration resulting from the workplace, such as:

  • decreased urine output or dark yellow urine
  • sweating
  • fatigue and weakness
  • dry mouth and increased thirst
  • headache
  • muscle cramping
  • poor mental and physical performance
  • dizziness

Suggested Management Plan

Senior workplace managers and supervisors need to be aware of the risks, prevention and treatment of dehydration. For larger organizations and companies, this is best done through the OHS officer or Medical officer.

A management plan should be developed in consultation with a medical practitioner.

The plan may include such components as:

  1. Description of the signs and symptoms of dehydration
  2. Assessment of the typical hydration status of workers e.g. a study on a randomized group of workers at start, middle and end of day. Dehydration status can be evaluated using urine colour charts, urine specific gravity and urine conductivity (ref 3,4). “Change in body mass” is the preferred method to assess dehydration (ref 4). Also, see Sports section. 
  3. Training of workers to self-assess their hydration status.
  4. Determine typical fluid loss rates (as perspiration and urine) in terms of Litres per hour, for workers according to major relevant groupings of conditions. For example:
    • light-moderate activity below and above 30 °C 
    • heavy activity below and above 30 °C
       
  5. Provide suitable beverages such as fresh cold water, juice and Hydralyte. The goal for workers is to match fluid intake with sweat and urine losses. In occupations and activities where the sweat rate is in excess of 1L/h for prolonged periods, it is generally not sufficient to provide only water, juices, soft drinks and sports drinks.(Some of these beverages, particularly high-sugar soft drinks, caffeinated energy drinks and sports drinks can interfere with the rehydration process). A recommended dosage for high sweat activity (> 1 L/h) is: 200 – 400 ml/h of Hydralyte for the duration of vigorous activity.
  6. Provide suitable rest breaks for workers
  7. Where possible, protect employees from prolonged physical exertion in warm-hot work conditions by making use of suitable clothing, air- conditioned rest areas and work vehicles, and appropriate equipment.
  8. Establish a procedure to follow if workers present symptoms of more serious heat-induced illness e.g. heat exertion or heat stroke

Hydration Pharmaceuticals can provide further information to your OHS staff on the management of  dehydration.

Warnings

Hydralyte contains approximately 0.8 mg/ml potassium. If you have kidney disease or are taking heart or blood pressure medicines – consult your doctor before using Hydralyte.
Hydralyte contains sodium. Refer to packaging for content.

References

  1. Hendry AL, Brotherhood JR et al 1997. Project Aquarius 8. Sweating, drinking and dehydration in men suppressing wild-land fires. International Journal of Wildland Fire 7(2): 145- 158.
  2. Gonzalez RR, Cheuvront SN, Montain SJ et al. 2009. Expanded prediction equations of human sweat loss and water needs. J Applied Physiology 107: 379-388.
  3. Shirreffs SM and Maughan RJ. 1998. Urine osmolality and conductivity as indices of hydration status in athletes in the heat. Medicine and Science in Sports and Exercise 30 (11): 1598-1602.
  4. Shirreffs SM. 2003. Markers of hydration status. European Journal of Clinical Nutrtion 57 Suppl 2: S6-S9