Heat Stress Management in Construction: MOM's New Safety Standards in Singapore

Introduction

The Ministry of Manpower (MOM) recently introduced comprehensive regulations of enhanced measures to reduce heat stress risks for outdoor workers. The measures include having the Wet Bulb Globe Temperature (WBGT) meter on-site for shipyards, the process industry and construction sites with a contract sum of over S$5 million. The measures also included mandatory hourly rest breaks under shaded areas when the WBGT exceeds 32 degrees celsius. 

These measures, effective from January 1, 2024, reflect the critical need to address the risks associated with heat stress, particularly highlighted by a tragic fatal work at height incident in 2022. This incident emphasised the importance of preventing heat stress, a concern further underscored by a recent NUS study shedding light on the challenges faced by construction workers. Previously in May 2023, contractors faced project delays up to 2 months and increased sick leave due to rising temperatures. 

These incidents prompted companies to adopt proactive measures to prevent heat stress, such as intensified monitoring of workers hydrating themselves and the provision of resources like outdoor fans and shelters in the worksites.

Despite these proactive steps, the introduction of the new heat stress regulation may present several challenges for construction companies. Uncertainties about regulatory requirements and difficulties in managing compliance documentation pose potential obstacles. Additionally, adapting existing safety procedures to meet the stringent standards and ensuring accurate data collection and analysis might prove to be significant hurdles, particularly for companies with large and dispersed workforces.

This article addresses the solutions to the challenges posed by the new regulation and explores effective strategies for managing heat stress, with a focus on safeguarding workers from the impacts of high-temperature conditions.

What is Heat Stress Management? 

Heat stress arises from the body's inability to eliminate excess heat, leading to various heat-related illnesses such as heat cramps, heat exhaustion, and potentially fatal heat stroke.

Aligned with new regulations, the use of the WBGT meter remains pivotal in accurately assessing the impact of heat stress on workers. Moreover, the recently completed NUS study, analysing construction workers' thermal demands and core temperatures, emphasised the need for tailored solutions and proactive measures to mitigate heat stress risks for a safer work environment. 

Implementing MOM Heat Stress Measures and WSH Council Regulations

MOM's heat stress measures prioritise outdoor worker safety, emphasising key practices like:

• Acclimatisation procedures
• Regular hydration protocols, e.g. hydrate at least once hourly
• Designated rest intervals in shaded and well-ventilated work areas
• Reschedule work
• Buddy System - monitoring of workers with early heat stress symptoms and signs of heat-related illnesses
• Implement emergency response plan for heat stress
• Monitor WBGT readings hourly 

These regulations demand that employers conduct thorough risk assessments and ensure appropriate safeguards against extreme temperatures, in accordance with Workplace Safety and Health (WSH) Guidelines on Managing Heat Stress. Furthermore, the regulations require workplace occupiers to take practical measures to protect workers from extreme temperatures, as specified under the WSH (General Provisions) Regulations. Under the WSH (Incident Reporting) Regulations, both employers and diagnosing medical professionals are required to submit online reports to MOM for heat-related occupational diseases. 

These stringent regulations have significant implications for construction companies, compelling them to reevaluate their current practices according to the regulations and prioritise the safety and well-being of their workforce. Such efforts are crucial to address the inherent complexities associated with managing heat stress effectively and ensure a secure and conducive outdoor working environment for all personnel.

Proposed Solutions for Heat Stress Management

Project HeatSafe, launched in 2020, seeks to comprehend the effects of temperature on worker health and productivity, suggesting practical solutions like work-rest cycles and shaded resting areas with improved ventilation. Another study on the distribution of ice slurry among construction workers has shown promising results in reducing body temperatures. However, these initiatives come with inherent limitations. In light of these limitations, construction companies must proactively explore alternative strategies to mitigate heat stress. Building on the urgency highlighted by the rising temperatures, the implementation of MOM's mandatory regulations comes as a timely and essential step for companies to prioritise worker well-being.

Implications for Singapore's Future: Managing Heat Stress and Climate Projections

The Centre for Climate Research Singapore highlights the urgency of effective heat stress management, with projected daily temperatures of 35 to 37 degrees Celsius by 2100. Escalating temperatures in early 2023 have led to construction delays resulting from workers taking sick leave and fatal work-at-height accidents, as previously discussed. This further underscores the importance of prioritising workers' well-being through active monitoring of the Wet Bulb Globe Temperature (WBGT) meter, aligning with MOM's heat stress reduction measures.

Ensuring Effective WBGT Meter Recording 

The WBGT meter is a widely-used heat stress indicator and the WBGT is derived from weighted averages of natural wet-bulb, dry bulb, and black globe temperatures. There are also prescribed parameters and calibration specifications of the WBGT that construction companies could follow. To effectively comply with the enhanced measures, construction companies must ensure hourly recording of the WBGT meter. This crucial step enables the assessment of heat stress risk levels, allowing timely breaks for worker protection. 

Conclusion

As the construction industry grapples with the persistent challenge of rising temperatures, effective heat stress management remains an ongoing imperative. 

MOM's forward-thinking regulations, coupled with the insights from the NUS study and the proactive measures of Project HeatSafe, underscore the necessity for continual vigilance and adaptive strategies. It is evident that the commitment to safeguarding worker well-being necessitates a perpetual emphasis on integrating evolving safety measures and harnessing advanced technologies to combat the escalating impacts of heat stress in the workplace. 

Contact us to find out how the Hubble Safety Management System can facilitate your company to adapt and comply with the enhanced measures to reduce heat stress risks.