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Beat the Heat

Published: 17th Jun 2014

Mitigation measures in shell's qatar pearl gtl construction project

The extreme heat stress conditions present in Qatar during the summer months require the implementation of stringent control measures to protect the health and safety of our workforce.

During the years of construction, Pearl GTL – the world’s largest Gas to Liquids plant in the world – developed its Beat the Heat campaign, taking into consideration learnings and best practise from across the industry, other countries in the region and across the globe.

In order to minimise the risk, a multi-pronged approach was taken under the canopy of the Project Heat Stress Prevention Procedure, based on the traditional risk management concept of Identify, Assess, Control and Recover.

Qatar’s massive Pearl Gas to Liquids facility, built in partnership with Qatar Petroleum, took more than 500 million man-hours to construct. At its peak the construction workforce reached nearly 53,000 persons, and keeping everyone healthy and safe was always the highest priority.


With summer daily temperatures in Qatar averaging in the 35 – 45 °C range, occasional peaks above 50 °C, and often high relative humidity, heat related illness (Table 1) was – and still is – a very real risk, especially with workers undertaking physical construction activities.

In addition to the severe climate, additional heat came through construction activities including welding, confined space work and manual activities – scaffolding, material handling or excavation. This was further exaggerated by the mandatory requirement to wear personal protective equipment ranging from the minimum coveralls, hardhat, gloves and safety boots, to additional specialist equipment such as respiratory protection and welding jackets.

As construction progressed more and more activities were carried out at height as the structures grew, and in confined spaces as equipment was installed, further adding to the heat burden.

Behaviour also plays a role in the risk of suffering a heat related illness. Keeping hydrated is a must in the fight against heat stress. By the time someone feels thirsty they are already suffering from some degree of dehydration, and with some nationalities the urge to drink is actually delayed until the body is already in a state of quite significant dehydration.

Assess – the flag system

The Pearl GTL Project implemented a system of coloured flags across the whole construction site. On an hourly basis the dry bulb temperature and relative humidity were measured using a field heat stress instrument, and the Heat Index (HI) and associated colour determined from a matrix (Figure 2).

The HI status was then communicated via text message across the entire site via a network of representatives who were responsible for raising a coloured flag representing the HI status.

People trained in the use of the heat instrument were also placed within the workplace, to confirm that the correct flags were in place, and that the communicated HI was applicable for the local environment such as in confined spaces, or areas with poor natural ventilation. These individuals were given the authority to upgrade the colour of the flag locally, but they were not permitted to downgrade it from the site wide colour.

The flag colour was an easy way of communicating to the entire workforce the current heat conditions, and also what actions were to be taken. Each flag colour had an associated work and rest schedule, the amount of water to drink and heat risks, with the most severe status, Black, meaning stop all work.

Every supervisor was provided with a pocket card to ensure that the details were available within every work party in addition to the posters displayed across the construction site.

Though there were/are more refined methods for monitoring heat exposure and effectiveness of control measures available, where there are such large numbers of persons spread over big areas, using the flag system provides a very practical and effective approach.

Control – be aware

Over the course of the project, 106 different nationalities worked on the site, with the majority of the workforce originating from the Asian subcontinent. Though English was the official project language, the majority of the workforce had very limited to no understanding of spoken or written English.

Any training or communication had to be provided in a way easily understood by the majority of the workforce. With Indian, Nepalese and Filipino workers representing approximately 77% of the total workforce, materials requiring written messages were translated into the principle languages, i.e. Hindi, Nepali and Tagalog respectively. Where possible, images such as the series of Heat Stress posters in Figure 3 were used instead of written languages to convey messages.

Before the start of each day’s activities every work party was given a toolbox talk (TBT) by a leader, ranging from the supervisor right up to the top management level. Though the main theme of the TBT changed constantly there was also a consistent message across the whole summer – to be aware of the risks of heat, and how to mitigate against them.

Drink water

To encourage drinking water fresh, cool drinking water was made available across the site, via regular deliveries of insulated igloos right into each work area. Every worker was given an insulated water canteen, and the carrying of a personal water supply was included as mandatory site personal protective equipment (PPE).

Hydration/dehydration (urine) charts, in the main languages (Figure 4), were displayed inside every ablution facility and people were encouraged to openly discuss the colour of their urine.

Take rest

Rest times provided in the HI/flag system were absolute minimums, to be taken in a shaded or cooled location, with all workers given the authority to take a rest whenever they felt the need. Supervisors were made accountable for ensuring that all of their workers followed the required rest schedule. In the hottest months workers tended to self regulate, with the rest periods being more than adhered to.

Qatar’s Ministry of Labour annually enforces adjusted work hours for the peak summer months. Though the oil and gas industry receives an exemption from the requirement providing there is demonstration of appropriate mitigation measures, the contractors working on the Pearl GTL site were given the option to adjust hours.

Where peak season adjusted work hours were adopted the shifts started earlier in the morning, finished an hour later in the evening, but included a three to four hour break over the lunchtime, getting the workers out of the hottest part of the day. During this time the workforce returned to their air conditioned accommodation to rest.

Acclimatisation also plays a role in risk mitigation. Workers new to Qatar were limited in the time they spent working out in the sun for the first few days, building up their exposure hours in a controlled manner.

Take food

Eating regularly contributes to the avoidance of heat stress, with breakfast playing a major role. During the peak summer period, to avoid working under the midday sun work hours were adjusted to start earlier in the morning. This resulted in workers rising very early with breakfast being served at around 3am. At this hour some workers find food unpalatable and there was a tendency to skip breakfast. Providing a mid morning snack particularly benefits this group of people, in addition to providing an energy boost to all workers with the result of increasing overall productivity.


Many of the construction workers were Muslim and participated in the fasting month of Ramadan. This complete abstinence from food and drink between dawn and dusk significantly increased their risk of sustaining a heat related incident.

To minimise this risk additional control measures were implemented including a shortened work day – six hours maximum – and wherever possible fasting workers were put on to nightshift.

Imams were brought onto the site to talk to the Muslim workforce, to put across the message that it is acceptable to break the fast for health reasons. Arrangements were also put in place to ensure that fasting workers had food and drink available at appropriate times, i.e. for their meal before dawn and after dusk.

With Ramadan moving forward 11 days per year, i.e. in 2008, it was from September 1 to 30; in 2011, from August 1 to 29, the month of fasting did not fall during the peak summer dates for all of the construction years. The added burden of fasting still impacted the risk of workers suffering heat related illnesses, however.


Every worker on the site was provided with information on the signs and symptoms (Table 1) of heat stress, and the basic first aid requirements. It was made the responsibility of every individual to not only look after themselves but also their colleagues, keeping both eyes open for any signs of heat stress.

Almost 30 Medical Aid Centres (MAC), manned by licensed nurses were established across the facility, supported by an on-site, advanced life support (ALS) service. Any cases of suspected heat stress had to be attended by a nurse as a minimum, and if necessary the ALS service was used to transfer the patient to the Ras Laffan Al Madina Clinic for higher care.

Cases of heat stress

Pre 2010, a heat stress occupational illness First Aid Case (FAC) was defined as a patient requiring intervention beyond treatment available at a MAC, i.e. requiring referral to a higher facility. A Medical Treatment Case (MTC) recorded those cases given intravenous fluids. A Restricted Work Case (RWC) occurred when the patient returned to work on a restricted (limited) duty, while a Lost Time Illness (LTI) was recorded when a patient missed a full day of work, excluding the day of the event.

At the start of the 2010 summer season the classification criteria were reassessed, with changes being made to the FAC classification. This was readjusted to then include all cases that required any intervention at MAC level, i.e. increasing the need to report into the statistics.

Graph 1 presents cases of heat illness as a rate, taking into account the changing size of the workforce over the construction years. Nearly 80% of all cases were classified as MTC, with the remaining cases being FAC – other than a single case in 2010 where an LTI injury was sustained due to an FAC heat illness.

In 2008, during the first six weeks of the hot season there were a significant number of recordable cases of heat stress, i.e. MTC or more severe, with many more FACs that were not even included in the statistics. A review was held and the flag colours were reassessed. This dropped the Black flag criterion down to 54 °C from 64 °C, and the Red flag from 54 °C down to 30 °C. Over the remaining six weeks of the hot season very few additional cases were recorded.

The clearer and newly defined reporting system established in 2010 resulted in a seeming increase in the number of recorded cases of heat stress. The reality, however, was that the more minor cases that previously had not been reported were now included in the statistics.

Taking learnings into account

Every case of heat stress was investigated to identify any underlying cause, particularly to identify any failure in management controls. At the end of each hot season a review was also undertaken, to ensure that any learnings could be incorporated into the following year’s strategy.

The high number of cases in 2008 reflected the level of controls that had been implemented at that stage of the construction project. Changing the flag colour HI bands resulted in a massive reduction in the rate of cases seen.

Rest shelters were insufficient in number, and often not positioned in the most effective locations, i.e. where natural draughts could be used to help cool the shelters.

In 2009, rest shelters were more abundant, better positioned and better designed, and in some locations air conditioned cabins were provided, particularly where confined space work was being undertaken. All workers were provided with personal water canteens, with water replenishment stations distributed in a dense network across the site.

Having built good relationships with the contractors, and gained the trust of the workers through the Qatar Shell Worker Welfare programme, meant that there was open communication, no hiding of cases and a willingness to share the positive and negative learnings.

In 2011, there was a big reduction in the number of Black flag cases. This was partly accounted for by the much tighter control on ‘Black Flag Working’, and also on the progress of the project, with the plant now approaching its operating phase and only limited construction and commissioning activities still going on.

And now

The Pearl GTL plant is now in full operation, and athough the manpower is vastly reduced from the days of construction, the risk of suffering a heat related illness continues to be very real.

The experience and learnings from the construction years has been pulled together, with an ongoing mitigation programme under the Pearl GTL Heat Related Illness Prevention Procedure.

Published: 17th Jun 2014 in Health and Safety Middle East

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