You are here

Personal Protection Equipment and Performance Degradation

Article, 13 November 2007
Technology
Whatever the reason for the use pf PPE, it is a requirement in an increasing range of work environments, so its impact on performance must be carefully considered.

In some situations, the wearing of PPE may contribute to, or cause, an incident. Often these are minor occurrences, causing inconvenience or annoyance, snagging clothing, tripping or knocking into objects. However in other instances the physical and mental changes that can occur when working in PPE may culminate in a more serious outcome.

Physical Effects

PPE usually takes the form of additional overclothing that is bulkier than normal working clothes. In our day-to-day activities we don't have to think about the external boundaries of our bodies and we can negotiate a range of tasks without having to consider how much room we need and where our feet and hands are spatially. When we don clothing that extends beyond the body's normal boundaries, we have to unexpectedly make a conscious effort to accommodate it and make allowances for the extra space our limbs and torso now require.

Even the most innocuous items like a lightweight cycling helmet may impact on performance. When one was introduced to the Formula 1 Pit Stop Crews it caused a significant drop in performance because they found the changes to the weight of their head and the larger space occupied created a significant loss of balance and slowed head movement down until they learned to adapt. Formula 1 pit stops are all about synchronicity and rapid movement involving an accurate interaction with seventeen other people, so even one person out of synchronization has the potential to add seconds onto the pit stop tasks undertaken.

Other simple forms of PPE and the performance altering impact that they have include:

  • Gloves affecting dexterity and grip
  • Tight clothing restricting joint movement and agility
  • Loose clothing hampering and impeding movement
  • Protective boots wider, longer and thicker than normal footwear, thereby altering gait and resulting in a loss of the tactual feedback needed for stability and sure footedness.

Where full body protection, which may include permeable or impermeable clothing and respirators or self-contained breathing apparatus (SCBA), is required the effects can be significant. Regular users of this equipment will have experienced how unpleasant wearing it can be and the speed with which fatigue occurs and individual performance degrades.

Fatigue

PPE such as body armour or other hazardous environment equipment is not only bulky but also heavy. As previously discussed, weight and bulk, particularly if it is on the head or unevenly distributed, significantly alters natural balance. This means that not only is the body carrying the additional weight but also the postural muscles have to work twice as hard just to stay upright. Clothing such as CBRN protection, which is very bulky, also restricts joint movement causing abnormal and exaggerated limb action plus necessitating muscles to work against the pull of the clothing.

Bulky clothing may prevent the operator seeing his feet, which is critical for a surefooted performance particularly when negotiating uneven ground or obstacles. Constant tripping is tiring, frustrating and recovery, particularly from a fall, expends a lot of physical energy. Falling over in SCBA can be particularly dangerous to the operator and the cause of damage to the equipment.

These factors combine to make the body work extremely hard to complete simple tasks. The effects of fatigue may be felt very quickly and there are many operations including mine clearance and firefighting where a loss of control over body coordination may result in undesirable movements such as tripping and staggering, that can in extremis precipitate the circumstances that lead to severe injury or even death.

Dehydration

Muscular effort produces moisture and heat that cannot escape through non-permeable materials, and apart from the physical discomfort of working when saturated with sweat, the lack of ventilation causes an increase in body temperature, creating more sweat. The body is 80 per cent water and our cells need water to function efficiently. Unless lost water is replaced, the body quickly becomes dehydrated. Even slight dehydration causes reaction times to slow down, increasing from an average of 250 milliseconds to up to two seconds, with obvious implications to task performance. Any task involving decision-making will degrade further as dehydration has a very negative effect on the quality of mental performance.

Prolonged dehydration when combined with continued exertion will quickly result in extreme fatigue, collapse, damage to the internal organs and eventually death. A combination of the need for chemical protection and high temperatures as is being experienced in Iraq at present necessitates the application of an effective risk management regime. This should determine what constitutes the greatest threat to health, chemical warfare agent poisoning or heat injury. Personnel wearing impermeable chemical protection suits are particularly vulnerable to heat injury practical experience suggesting that in temperatures exceeding 25 degrees Celsius core body temperatures may hit damaging levels within twenty minutes.

Cognitive Effects

Visual Cues

While visual cues might be expected to appear under the physical section, working in respirators, masks or helmets has cognitive implication caused by the loss of peripheral vision. Peripheral vision has an important role to play in our interaction with the world. It acts as an alerting system to warn us about new objects coming into our environment and of potential threats and it puts objects that we are focussing on into a more global context. When peripheral vision is removed its loss for some people can be unnerving and make them feel vulnerable, while for others it closes their world down and they become unaware of the wider picture or potential threats. People experiencing the latter can become so focussed on the task or the part of the world they can see, that they forget to monitor the environment and therefore are unaware of impending danger or important new information.

Situation Awareness

The loss of situation awareness (SA) can lead to some strange behaviour by those affected. To have good SA we need to be able to carry out three processes; receive relevant information, process the information and then make a prediction about what to do under the specific circumstances. If PPE prevents people from getting the right information it can also cause them to make incorrect assumptions about their world. This means that the mental processing is based on false information and the subsequent decision-making is consequently faulty. The better the apparent solution to a problem appears to be, the more committed an individual will be to its success and the belief that it is accurate. Therefore, if at some point in carrying out their plan a person discovers that an assumption they made about their world is inaccurate, they will be far less likely to recognise it and will try to make the discrepancy fit their original plan. When the plan finally collapses the person often becomes totally disorientated and is unable to reassemble information about the situation to rectify it.

This phenomenon is called 'violation of expectation' and can prove to be extremely dangerous in hazardous situations. If, for example, you have based your escape strategy on information that a particular door opens to stairs that lead to safety and when the time comes to get out you discover that it is in fact a broom cupboard, instead of re-evaluating the whole environment to review your understanding of the situation, there is a possibility that precious time will be spent on making the environment fit the faulty plan. PPE prevents rapid reappraisal and narrows the operator's world anyway, so the search for the correct door is likely to become haphazard or over-fixated on the wrong aspects of the environment.

The panic that may ensue, with total collapse of a whole strategy, may result in Standard Operating Procedures (SOPs) being abandoned and a new unrealistic plan being formulated, accompanied by the risk of oxygen depletion as a result of unnecessary exertion and hyperventilation.

Risk Homeostasis

Risk homeostasis is a feeling of invincibility. The wearing of PPE may engender in some individuals a sense of false security, particularly if the threat is silent or invisible, and is particularly relevant to those individuals who feel safely cocooned in their PPE. This, combined with the mental effects of fatigue and dehydration (i.e. poor decision making, disorientation and illusion) may persuade the individual that they are invincible with the following consequences:

  • If operating underwater SCBA equipment, that rapid surfacing may be undertaken without any risk of the bends.
  • In fire-fighting situations that it is possible to walk into the heart of an intense fire without injury.
  • During bomb disposal operations that an EOD suit will provide immunity from the effect of blast and fragmentation.
  • Where there are unstable or weak structures that they can be walked on safely and that they will support body weight.
When wearing SCBA, an individual may experience the 'just one more minute' syndrome, pushing the boundaries and losing track of time, resulting in depletion of compressed air/oxygen or succumbing to the effects of heat and exhaustion. Oxygen depletion contributes to hallucination and may cause an individual to remove PPE in the belief that it is safe to do so.

Conclusion

Personal Protection Equipment is a key requirement to health and safety regimes and is essential to survival in a wide range of hostile environments. The wearing of PPE does, however, result in exposing the wearer to a range of negative physical and psychological factors. Risk assessment and management and thorough familiarization coupled with extensive training in realistic scenarios will mitigate the negative impacts of wearing PPE.

Nikki Heath is a performance psychologist and managing director of P4CT.

Support Rusi Research

Subscribe to our Newsletter