Cool clothing counters heat's hazards
Frank Higgins addresses behavioural safety and the use of PPE in the heat.
The holy month of Ramadan falls this year not only during the hottest month, but at a time where our colleagues can be fasting for up to 14 hours a day.
This, along with doing their job and wearing personal protective equipment (PPE), can make some workers more prone to heat related illnesses. Management needs to be aware of the risks and ensure that programmes are in place to protect employees.
Working for prolonged periods in excessive temperatures, high humidity and direct sunlight can induce heat related illness. Each year heat related illnesses account for thousands of Lost Time Injuries (LTI), all of which can be avoided through good management controls.
During activities in prolonged heat, management must conduct a risk assessment to control workers’ risks. In some cases it will be inevitable that the control measure for outdoor workers may result in the wearing of PPE. Where PPE is the only option available, managers need to assess employees’ reactions to wearing PPE for prolonged periods in hot and possibly humid climates.
During hot periods, management needs to be aware that employees’ behaviours may change in relation to PPE, due to the increase in heat and/or the poor selection of PPE. In situations where employees have not been included in the selection process, equipment choice is often based on cost, as opposed to its suitability or quality for the work to be undertaken, or the environment in which the wearer will operate. To ensure compliance, management needs to involve employees in the selection criteria, as this intervention will make employees feel that they are part of the process. Management must lead by example to set standards and maintain compliance with safety programmes.
PPE is designed to give protection, but what should we do if this endeavour to protect workers causes more problems than it mitigates? When working in the heat, PPE can be part of the problem; for example, due to discomfort from excessive sweating caused by the use of non-breathable materials, and the layering effect of wearing a helmet, coveralls and gloves. Ambient and radiated heat from equipment and processes further compounds the heat stresses.
Believing that they are preventing heat related illnesses many employees simply refuse to wear PPE, citing comfort and suitability as problematic in hot climates. Although this is sometimes the case, in doing this they can actually expose themselves to more serious health risks. Management can overcome this through the use of education and training, to raise awareness on the correct selection and use of equipment with cooling capabilities that can help the wearer reduce heat effects on the body, thus helping to reduce injury due to heat illnesses.
Cooling products give the wearer a selection of PPE that will be suitable for them and the task that they are going to undertake, but it is important that the wearer understands the principles of the cooling effects that a garment will offer. The wearer also needs to be trained in using the garment, as different products on the market provide different types of cooling and use different techniques.
Selection of PPE is always hard when you have to account for different perceptions. Some employees want style, others look at cost, whereas some think that anything is better than what they’ve had before. With cooling products the challenge is no different.
Employees’ comments on cooling workwear include: This does not work It is too cold I need to keep wetting it
So, how does management ensure that the product selected is the right one? This can be done simply by introducing the item and receiving feedback from employees regarding its quality and functionality. By getting this right, workers will wear and care for the PPE.
Feedback, too, will instil in the wearer not only that the PPE does indeed work, but more importantly that the management cares.
When selecting PPE to manage heat stress, several factors need to be considered:
Physiological response - Heat dissipation to prevent the rise in core body temperature
Psychological response - Non acceptance of PPE will result in non use and/or incorrect use
A skull cap is an example of a cooling product where, although it is additional PPE, it provides the necessary protection for cooling while at the same time not affecting the safety standards, or restricting the wearing of conventional PPE.
When choosing some cooling products it may be that you inadvertently introduce another layer of clothing. This in itself could give the wearer the misconception that this will be warmer and more restrictive when doing their job. They will not always see the benefits of the PEE minimising the likelihood of illness due to long periods exposed to high temperatures. This can be overcome, however, by introducing a particular item in cooler months and getting workers to wear a garment initially for short periods, leading up to wearing it for the duration of a shift.
Technical performance is a very important factor as a manufacturer’s data may represent only the specifics of a particular working situation, or environment in which a product was tested. It may therefore not be possible to determine how long the cooling effects will last without first trying the PPE in the relevant work areas.
Types of cooling PPE
PPE designed to manage and prevent heat stress works primarily by promoting cooling. The following sections outline several types of cooling PPE.
Head and neck bands
Worn around the head and neck as well as other parts of the body, most cooling bands contain crystals that absorb and hold cool water for long periods. These bands can be reused and if the cooling effect is wearing off, the band can be re-submerged in water and the cooling effects will recommence. Head and neck bands are not designed to absorb perspiration, but are intended to keep the body cool and to reduce perspiration.
Hard hat liners and shades
Hard hat liners and shades are available in various styles. Some liners are made from an absorbent material like cotton.
When this head protection is used, management must also look at rehydration to replace the electrolytes lost due to sweating. Other liners use the same crystals that are found in head and neck bands. Hat liners may completely line the hard hat or just attach to the hat’s harness suspension.
Shades to protect the back of the neck from the sun are available with or without cooling crystals. These are primarily designed to block the sun from the back of the neck and facilitate evaporation of perspiration.
High visibility vests
Vests are currently available incorporating a variety of technologies. Some systems include frozen elements, either by inserting a frozen gel or ice pack into the vest pockets, or by freezing the entire vest. Other vests feature circulation systems, which pump air or cool water throughout the vest. The third type of system is a phase-change cooling system. This uses a pre-treated pack that is frozen or soaked in water prior to insertion in the vest. As heat is absorbed from the body, the material then changes back into its liquid state. It is worth noting that in this final type of system, cooling times can vary considerably.
Hydration backpacks provide a source of fluids to prevent dehydration. Although the primary function is not to cool the wearer, the reservoir provides some cooling until all the liquid is used. These backpacks offer hands free access to drinking water.
Wrist bands are also available with the same cooling crystal technology found in head and neck bands and helmet inserts. This design puts the cooling mechanism next to the pulse points, which reportedly helps to transport the cooling sensation around the body.
Many special fabrics are available to assist in cooling. They feature breathability and enhance the transportation of moisture away from the skin.
Suggestions for workers
Workers should avoid extreme heat, sun exposure and high humidity where possible. If exposure cannot be avoided, workers should take the following steps to prevent heat stress:
Wear light coloured, loose fitting and breathable clothing such as cotton
Avoid non breathable synthetic clothing
Gradually build up to heavy work
Schedule heavy work for during the coolest parts of the day
Take more breaks in extreme heat and humidity
Take breaks in the shade or a cool area when possible
Drink one cup of water every 15-20 minutes so that you never become thirsty
Avoid alcohol and drinks with large amounts of caffeine or sugar
Be aware that protective clothing or PPE may increase the risk of heat stress
Monitor your physical condition and that of your co-workers
Use your cooling products and ensure that you follow manufacturers’ guidelines
Working in the heat is no different to individuals working in any other medium to high risk activity. Work must be assessed, with control measures put in place. Just as in any other industrial activity, if the control measures to combat heat stress are insufficient or inappropriate, this could result in accidents, injuries and even fatalities.
Ensuring the correct measures are in place is the responsibility of management, but it is everyone’s responsibility to be mindful of the risks present. Where PPE is required to control core body temperature, it is important to ensure that the selection process is robust and that employees are part of the process.
Published: 17th Jun 2014 in Health and Safety Middle East