Risk assessment and occupational safety in steam boilers
The National Board Inspection Code (NBIC) and the Factory and Machinery Act (Malaysia) recognized the potential hazards of steam boilers and established various codes and regulations related to hazard control and risk minimization. Every year authorized inspectors inspect by fire and water for defects, scale and corrosion. Every year, all essential valves and accessories are disassembled for inspection. The thickness of the plate is checked, the results of the analysis of the boiler water are reviewed, and in fact, the authority applies rigorous maintenance on steam boilers, but still, several boiler accidents occurred. One might wonder why. The reason lies in one prominent factor: human error is the leading cause of boiler accidents. One statistic indicated that 83% of boiler accidents were the direct result of human error due to lack of knowledge and awareness. Although the inspection has become strict, the local authority does not cover the inspection of the boiler safety controls and all routine or non-routine activities. OSHA can only provide guidelines for workplace safety, but ensure that implementations are beyond its scope.
The root cause of hazards in an organization are organizational deficiencies. Deficiencies may be related to safety controls, safe operating procedures (SOPs), hazard and risk assessment and controls, and training or awareness. With deficiencies, employees generally do not realize the dangers and consequences of their actions. Therefore, to minimize or eliminate the risks exposed to all employees, contractors and visitors in its activities, an organization must establish an occupational health and safety (OHS) management system. Only through OHS can hazards be recognized and health and safety risks adequately assessed and addressed. Management can set objectives, provide adequate controls, provide sets of procedures (SOPs), organize training programs, and establish a safety performance evaluation.
Boilers have many potential hazards that must be controlled through safety devices and safe work practices. Before identifying hazards, you need to understand the meaning of hazards. In this context, hazard is defined as “a source or situation with the potential for harm in terms of injury or illness, damage to property, or a combination of these.” To begin to identify hazards, management must know what activities are involved. Activities can be divided into two categories that are routine and non-routine. Routine activities include daily operation, chemical preparation, and fuel storage and handling, while non-routine activities include checking the boiler, entering confined spaces, and responding to emergencies. The first stage in hazard identification is a selection of work to analyze.
Management must first select key activities, such as daily operation and chemical preparation. In the second stage, SSO management consists of dividing activities into logical steps. The logical steps should be unique to the activities and trivial activities such as turning on the lights should be avoided. For example, taking data from several meters during operation or pouring chemicals from the boiler into a flask. In the third stage, management consists of identifying hazards and determining the corresponding risks at each step. When preparing boiler chemicals, boiler operators are exposed to corrosive liquid spills and acid gases. The risk is the consequence, and in this case the risks are injury and pain to the eyes, burns or cancer if hydrazine is handled. A high noise level above 85 dBA is an example of a danger in daily operation and the risk is obvious, which is deafness. In stage four, management must develop risk elimination or reduction measures.
For high noise levels, risk elimination or reduction measures would require path noise control, such as acoustic insulation (lining) or acoustic partition, enclosure for noise radiation source, increase pipe size to reduce steam turbulence or install a noise diffuser. The best approach is to control noise at the source, such as installing a muffler, changing equipment, for example changing the normal pressure reducing valve (PRV) to a low noise PRV. Other risk controls for high noise levels would be the use of personal protective equipment (PPE) or the reduction of the exposure time. The most common danger to boiler operation is low water level and the risk could be permanent damage to the boiler or an explosion. Modern boilers are generally equipped with automatic level controllers, low water burner interlocks, low water alarm, and regular checking of meter glasses by boiler operators. All of these are risk controls using safety devices. Working in confined spaces is a non-routine activity, the associated hazard is physical injury or death from suffocation or poisonous gas, and current hazard control follows confined space entry guidelines, which will not be discussed here.
When pouring the chemical into a bottle, the danger is splashing chemicals in the eyes and the risk is eye damage and injury. From this, the risk control would be using safety glasses. Another example of daily operation is blasting. The blowdown can cause hot water to spill, which is the hazard, and can burn boiler operators, which is the hazard. The example of hazard control is blowing into the purge chamber rather than directly into the atmosphere, which reduces the potential spillage of hot water to the surroundings.
In the final stage, after the job safety analysis is completed for each activity, the activities, hazards and risks, and the corresponding risk controls should be documented for reference. Based on that, safe operating procedures can be established to ensure that workplace hazards can be eliminated or minimized. Training should be delivered by the competent person in charge to all boiler operators to explain in detail the hazards, risks, controls, procedures and responsibility, as well as accountability.
For any organization that does not have a structured OHS management system, I would recommend OHSAS 18001 or MS 1722 certification. OHSAS 18001 or MS 1722 provides a set of procedures and tools to promote continuous improvement through hazard identification, evaluation risk management and risk control in a very systematic way. In addition to these benefits, I have noticed that with the implementation of the OHSAS 18001 standards, my organization’s management and employees have significantly improved their understanding of health and safety legislation, as well as their ability to demonstrate compliance.
