Working at Altitudes and Good OHS Practices

21 October, 2020 | Blog

Karine Benazera, P.Eng.

Practice Leader, Project execution

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Sylvain Boily

Sylvain Boily, P. Eng., MBA, PMP

Project Manager - Operational Readiness and Commissioning

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We don’t often work at high altitudes and in remote mountainous regions. So before taking on such work, it’s important to fully understand associated risks and to take the necessary measures to ensure the health and safety of employees who’ll be carrying out such work.

At BBA, occupational health and safety (OHS) values guide our choices and decisions every day. Before every mandate, we perform a risk analysis of the work, in cooperation with the employees involved and client OHS representatives.

High altitude effects

At high altitudes, atmospheric pressure drops, as do oxygen levels. The amount of oxygen available at an altitude of 3,000 m is two-thirds of that available at sea level and is half of that at 5,000 m.

In high altitudes, people are in a state of hypoxia, the medical term for a lack of oxygen. As a result, the human body reacts by developing physiological mechanisms that restore oxygenation to make up for standard cellular needs.

The first stage of hypoxia is acclimatization, which accelerates your breathing and heart rate. These beneficial ventilatory and circulatory reactions increase oxygen supply to the cells. However, they cause your lungs (hyperventilation) and hearth (tachycardia) to work too hard, in addition to impeding circulation in your brain.

When your body is exposed to hypoxia for a long time, it adapts and sets up mechanisms that gradually replace hyperventilation and tachycardia. However, this needs to occur progressively and over a sufficient long period of time for these mechanisms to be effective.

The ability to adapt to high altitudes doesn’t depend on an individual’s physical condition nor on the number of previous stays, age or gender. The number of red blood cells responsible for transporting oxygen in the blood significantly increases after at least one week of exposure.

Symptoms

Every individual reacts to hypoxia differently, but the following symptoms may appear together or on their own within the first few hours of exposure:

  • Headaches
  • Vertigo and balance issues
  • Nausea, lack of appetite and stomach disorders
  • Trouble breathing
  • Fatigue, sleep disorders and drowsiness
  • Irritability
  • Decrease in urination

These symptoms are normal and usually disappear on their own after a few hours at altitude and taking pain medication. In some cases, serious complications may occur, such as:

  • Coughing, spitting, blue lips, insufficient breathing
  • Sharp headaches that cannot be relieved with aspirin, vomiting, vision issues

In these serious cases, the individual must be taken to a lower altitude as quickly as possible and seen by a physician.

Risk analysis

Adhering to BBA’s OHS policies requires that all individuals who need to work at high altitudes perform a risk analysis beforehand.

When working at high altitudes, the risk analysis and management process must include:

  • a medical examination to ensure there are no contraindications to working at altitudes
  • a list of warm clothing to be provided depending on weather conditions
  • a first-aid kit, which may include an oxygen cylinder
  • an audit of client health and safety procedures and emergency response plan
  • establishing a consistent emergency response plan

Moreover, while travelling to the site, checkpoints must be provided where the vehicle operator will need to stop to provide the status of passengers and the vehicle to a designated person. If this person does not hear from the driver at the scheduled time, he or she must initiate the emergency protocol to assist the vehicle and its occupants.

After arriving at the site, employees must pay attention to symptoms associated with working at high altitudes and report them to the medical personnel on site.

Conclusion

Before performing work at high altitudes, it’s important to do research to fully understand the location’s environment and characteristics where the work will occur. Moreover, you need to work with the client to first identify health and safety procedures and develop an emergency measures plan that’s adapted to the site.

This content is for general information purposes only. All rights reserved ©BBA

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