Ingenieur Vol. 64 Oct-Dec 2015 Ingenieur Vol 64 Oct-Dec 2015 | Page 62

INGENIEUR In terms of identifying any potential risk of hazard and operability issues of the sewerage facilities, Hazard and Operability study (HAZOPs) have been introduced to the Malaysian sewerage industry since the mid-1990s. It is a structured and systematic examination of a planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel or equipment, or prevent efficient operation. HAZOPs originated in the 1960s at Imperial Chemical Industries (ICI), a major British international chemical company at the time. In Malaysia, the requirement to conduct HAZOPs has been incorporated by Sewerage Ser vices Department (SSD) in the 1990s and is continued to date by Suruhanjaya Perkhidmatan Air Negara (SPAN) in the Malaysian Sewerage Guidelines (MSIG). Before the establishment of Sewerage Guidelines and HAZOP studies requirements, the sewerage facilities were unsafe and some were difficult to manage and operate . The aim of HAZOPs is to ensure that sewerage facilities are designed in a good and safe manner to minimize hazard and operability issues, by imposing risk control or risk reduction. The methods of risk control and reduction are commonly referred to as the Hierarchy of Control. Occupational safety and health professionals use the hierarchy of control (shown in the Figure E) to determine how to implement feasible and effective controls. In most cases, the preferred approach is to eliminate the 6 60 Figure D: Risk Categories Controller System to Ensure Business Outcomes Figure E: Hierarchy of Hazardous Controls source of hazards. If the hazards cannot be controlled through elimination of the source or substitution of quieter equipment, engineering controls may be installed to reduce hazards to safer levels. Usage of personal protective equipment (PPE) is the last option in the hierarchy of control. PPE is generally less VOL – DECEMBER 2015 VOL64 55OCTOBER JUNE 2013 effective than elimination, substitution, and engineering controls because they rely on human actions to reduce hazards. Used in combination with other levels of control, such as administrative controls, PPE may provide worker protection when engineering controls do not adequately remove the hazard.