Risk and Safety Analysis Models

Risk is the multiplicative product of severity and likelihood of hazardous event. The workers takes risks in their assigned jobs depending upon their risk perception, safety rules & procedures and management [97]. The risk level of different hazardous activities prioritized by using risk assessment methods provides viable knowledge to safety professionals to set company goals and objectives [98]. Issues related to occupational health and safety are quite common in the downstream of oil and gas industries. These include fire, falls, electrocutions, vehicle accidents, robbery and snakebites. The level of risk of these hazards varies according to location and country. PFS’s are commonly located in the vicinity of populated areas to facilitate refuelling operations. They pose a significant risk to people, property and the environment [86]. Although PFS’s are not costly infrastructures, due to possessing flammable and hazardous materials they acquire attention. The construction cost of PFS that constructed in 1998 and 1999 were ranges between 1.4 million to 4.0 million Pakistani rupees as indicated by [34]. The variation of the cost depends upon the various parameters, such as: is the PFS located in an urban or rural area, is it a covered area, availability of other components, is there a provision for allied facilities and etc. It was noticed that major and minor accident and incident cases were not independent of each other. They were, instead, interrelated with one another. Many risk assessment models were studied during this research but no base data was found.

If the risks are calculated by using the risk assessment criteria developed for the construction industry in the petroleum sector and vice versa, it will not give suitable risk values because the working environment in the construction industry is totally different compared to the petroleum sector. The choice of the most relevant risk assessment method is mandatory to calculate the accurate risk.

Risk management is one of the main components of the health and safety (H & S) management system. There are various ways to calculate the risks associated with various work trades. Many researchers have suggested different methods to determine risks based on some specific parameters. The importance of a risk evaluation can be viewed easily by observing that many companies make it a part of its health and safety policy. This is the responsibility of the company to conduct its operational activities in a manner that minimizes HSE risks. Protecting the health and safety of employees, contractors, customers and the community at large in the

environment in which the group activities are being conducting is vital. Any company with active involvement of all employees and contractors can manage HSE risks to prevent accident, injuries and occupational illnesses.

Various risk assessment models proposed by different researchers were reviewed during the study period. The detail descriptions of three most widely in practice risk and safety analysis models are discussed in detail below. These were As Low As Reasonably Practicable (ALARP), Risk Matrix Criterion and Risk Ranking Criterion.

2.9.1. As Low as Reasonably Practicable (ALARP)

ALARP is a documented and well established process for performing detailed risk assessment. It is necessary to perform detailed risk assessment in compliance to the standard code of practices, and also to satisfy the concerns of the buyers [24].

ALARP assures the protection of the company’s people, assets, reputation and protection of the environment that the company operates in. This risk assessment criterion is used for identification of hazardous activities. During the risk analysis process, the appropriate consequence and probability were assigned to the respective hazards. The risk analysis by ALARP is covered in section 1.4.1. The detail description of some components is described below;

2.9.1.1. Consequence of Hazard (Top Event) - Consequence on People A consequence of Hazard on people in ALARP can be described as a rating of “0”

(zero); this rating severity on people indicates no injury. The rating of “1” reflects a slight injury or health effect. It includes first aid and MTC. Under this rating there is no affect on the work performance or cause of a disability. The rating of “2” indicates a minor injury or health effect. This ranking includes lost time incidents and injury (LTII) cases. It affects work performance, e.g., restriction to certain activities (restricted work cases) or required to take a few days rest to recover like with food poisoning and skin irritation. The “3” rating (major injury) includes permanent disability. Activities under this group cause prolonged leave, e.g., unlimited absence from work, irreversible health loss, chronic back injuries etc. The rating of “4”

defines those activities that can cause single fatality or permanent total disability. It can be caused by an accident or occupational illness (cancer). The rating of “5” is

considered to be the main cause producing multiple fatalities. It can happen due to an accident or occupational illness.

2.1.2.1 Consequences on Asset

According to ALARP consequences on Assets are divided into 6 broad categories .i.e.

no damage, slight damage, minor damage, local damage, major damage and extensive damage. This division is based upon the cost assigned to different incidents and accidents by the company. The cost increases from no damage to extensive damage in ranking. This cost to the individual rating normally varies from organization to organization.

2.1.2.2 Consequences on the “Environment”

The consequences on the environment are categorized into 6 main groups. Ratings are assigned from “0” to “5” and the effects on the environment are no impact, slight impact, minor impact, localized impact, major and massive impact, respectively. The rating of “0” (zero) indicates no effect on the environment. The rating of “1” shows a slight impact; it can cause local environmental damage. It affects the environment within the boundary/fence or within the system. It causes negligible financial consequences. Minor impact causes contamination, violation of statutory laws and local complaints. There is no permanent /long lasting effect on the environment. The rating of “2” indicates a minor impact on the environment. A localized impact has a rating of “3” and covers limited loss of discharges/fuel, repeated violation of statutory byelaws, and affects the community and neighbourhood. Major affects on the environment have a rating of “4” and defines a severe damage to the environment.

Under this category, a company is restricted and must take maximum measures to restore the contaminated environment to its original state. Massive impacts have a rating of “5” and include persistent severe environmental damage over a large area, and commercial, recreational or natural loss. The rating of “5” also indicates a major economic loss to the company, repeated high violations of statutory byelaws or prescribed limits.

2.1.2.3 Consequences on Reputation

The consequences on the reputation of a company with reference to ALARP is described as; no impact reflects that there is no harm on the company reputation due to that particular accident or incident. A slight impact rating shows that public awareness may exist, but there is no public concern about the organization with its

activity. A limited impact defines that there is some local public concern. A considerable impact indicates that there is regional public concern. An extensive impact results in adverse highlights being given attention in the local media and there is an adverse stance by the local government and/or action groups. A major national impact defines the effects on national public concern, and a major international affect describes the national/international policies with a potentially severe impact on access to new areas, grants of licenses and/or tax legislation.

2.9.2. Risk Matrix Criterion

The risk matrix evaluation method is widely used in upstream oil and gas sectors in Pakistan to determine risks. The description of hazards analysis with reference to risk matrix criterion is described in section 1.4.2. Some literatures present likelihood as a frequency or probability. Table 1.4 shows the risk matrix criterion to calculate the risk score associated with hazardous activities. Table 1.4 is divided into 5 rows and 5 columns. Likelihood is represented on the X-axis and severity is represented on the Y-axis. Likelihood is divided into four categories, i.e., extremely likely (E), often likely (F), unlikely (G) and very unlikely (H). A number value, i.e. (10), (08), (06) or (04) is assigned to each category, respectively. Severity is also divided into four main categories, i.e. death or permanent disability or extreme damage to equipment or property, long term illness or serious injury or major damage to property or equipment, medical treatment with several days off work or minor damage to equipment or property, and first aid needed or negligible property damage. A number is assigned to measure the impact as (A) 10, (B) 08, (C) 06 and (D) 04.

During risk analysis, a severity and likelihood value is assigned to the hazardous event. With multiplication of the severity and likelihood values, a risk score value is calculated and put up, respectively in Table 1.4. Finally, the risk evaluation needs to be carried out according to Table 1.5

2.9.3. Risk Ranking Criterion

The methodology for hazard analysis with reference to risk ranking criterion is described in section 1.4.3.