RISK ASSESSMENT METHOD REGARDING TO ENVIRONMENTAL IMPACT AND SAFETY AND HEALTH OF WORKERS

Transcription

1 Proceedings of the 12 th International Conference on Environmental Science and Technology Rhodes, Greece, 8 10 September 2011 RISK ASSESSMENT METHOD REGARDING TO ENVIRONMENTAL IMPACT AND SAFETY AND HEALTH OF WORKERS DANIELA DORINA FULOP 1, and TIBERIU RUSU 2, and TIMEA BODEA 3 1 Technical University from Cluj-Napoca, Faculty of Materials Science and Engineering, Departament of Environmental Engineering, Bld Muncii, nr , Cluj-Napoca,post code: ,Romania. 2 Technical University from Cluj-Napoca, Romania. 3 Technical University from Cluj-Napoca, Romania daniela.fulop@gmail.com EXTENDED ABSTRACT Industrial activities are an important part of the economy, but at the same time, they contribute to environmental pollution, to the production of waste and are also energy intensive. Despite a reduction in emissions occurred in recent decades, industrial activities remain a major source of pollution. Achieving security and health of workers requires the removal of risk of injury and disease, characteristic of elements that compose the system's own work. This paper presents a simple and accessible risk assessment on environmental impact and safety and health of workers in the pulp and paper industry. The method is also applicable in industries where pollution is a major risk for environment and facilities that pose a high risk of injury and illness for operator and maintenance personnel. The method can be successfully applied in the following industries: petrochemical, chemical, metallurgy. The proposed method of quantitative determination of the level of risk / safety for a system of production based on systemic analysis and risk assessment considering the risks of possible environmental impact and safety and health of workers. Applying risk assessment concludes with a summary document (job evaluation system), which includes the global risk analysis system which is based on the rationale of the program to prevent environmental pollution accidents in technical or human error and industrial accidents and occupational diseases for workers in the manufacturing process. Advantages of the proposed evaluation method: -The proposed method of risk assessment on environmental impact and safety and health of workers is cheap, accessible and easily implemented by experts of any firm producing pulp and paper. This method allows to identify risks that can have serious consequences on the environment and the on safety and health of the personnel, risk assessment ending with a summary of proposed measures, in which are notated the measures proposed to reduce / eliminate unacceptable risks with clear deadlines and responsibilities. Keywords: risk assessment, health of the workers, environmental impact, pulp and paper industry. 1. INTRODUCTION The concept of risk is characterized by torque probability (frequency) of occurrence / severity of the consequences applied to a random phenomenon. Α-570

2 Can be defined as the theoretical risk acceptability curve (figure 1) (Alexandru, 2007). Figure 1. Risk acceptability curve Acceptability curve allows distinguishing between acceptable and unacceptable risk. Risk (event) is important plot point that is through an appropriate coordinated "likelihood" of the event (X) and severity (size) loss (Y). In this situation, the risk corresponds to the event "A", which has a very low probability but serious consequences of achievement equals an acceptable risk, while the corresponding risk event "B" from the chart, with less serious consequences but is high probability of achieving equals an unacceptable risk. The risk based maintenance and continuous monitory of equipments stage are in close interdependence, which is the only counterwork solution of unexpected breakdowns appearance. The determination produced risk of damage and technical unexpected breakdowns are realized with the risk matrix depending on gravity and probability of damages appearance (Barratt, 2005). Risk items are shown in figure 2. The risk matrix is presented in figure 3. Figure 2. Risk elements Α-571

3 Figure 3. The risk matrix The implementation stages of risk based maintenance are the following: - identified the component elements and functions of the equipments; - identified the probability that this component element functions not accomplished, and the possible damages of the equipment elements; - the analysis of probability and risk produce at the equipment elements of paper machine; - identified the causes of damage risk appearance and solutions to avoid the risk appearance; - establish maintenance process for equipments protection avoiding the failure risk appearance and planning the specific demands for avoiding risks; Risk assessment method presented applies primarily industrial systems are made up of (Barratt,2005): - boilers and pressure vessels; towers and storage or cooling tanks under pressure; - pumps and compressors, industrial fittings (shutters, valves, clack valves, pressure control valves); - the installation of pressure piping, safety devices pressure installations; This method of risk assessment after four categories of analysis can be applied to the industrial systems specific pulp and paper industry, chemicals and petrochemicals. Method of quantitative evaluation of the risk level of a system of production of pulp and paper industry was developed by the author based on the method of determining the risk level for risk of injury and illness of workers, realized by the National Institute of Research on Occupational Safety Alexandru Darabon (NIROSAD) Bucharest. Quantitative determination of the level of risk/ safety for a system of production based on systemic analysis and risk assessment following criteria: - safety and health of the workers in the environment of analysis system; - environmental impacts of the system damages, technical accidents; - financial impact of damages and stops of the analyzed system; Applying the risk assessment ends with a summary document (schedule of evaluation of the system), which includes the global risk analysis system which is based prevention program accidental stops, work accidents and occupational diseases for workers of production process, environmental pollution accidents. Security level for a job is inversely proportional to the level of risk (Băbu, 2007). To identify the risk factors of the examined system, through a technological process will follow the next steps (Fulop et al., 2009): Α-572

4 1. Defining the system to be analyzed; 2. Identifying risk factors of system; 3. Risk assessment of damage and casualties technical system, accident and sickness of workers, environmental pollution and economic and financial risk; 4. Prioritize risks and establish priorities for prevention; 5. Prevention proposal; 2. TOOLS USED FOR RISK ASSESSMENT 1. Determination and recording on a scale of 1-5 of knowledge about the system (equipment and installation) rated. Determination and recording of knowledge about the system (equipment and installation) evaluated include: - Technical design, materials used, type and year of manufacture; - History of equipment and loads its operating parameters; - Background on the inspection equipment, operation and the time elapsed since the last inspection based on risk; - Working environment in which they operate the evaluated machinery or plant; - Mechanisms of damage and deterioration rate of equipment parts evaluated; 2. Assessment and registration on a scale of 1-5 of the adverse effects of design errors and the state of the system from carrying out inspections based on risk. 3. Severity rating scale environmental consequences of failure (figure 4). SEVERITY CLASSES SEVERITY OF THE CONSEQUENCES CONSEQUENCES 1 NEGLIGIBLE Minor damages on the environment 2 LOW Short-term damage to local environment (t <1 month) 3 MEDIUM The time need for restoration of the ecological system is less than two years 4 SERIOUS The time need for restoration of the ecological system is between 2-5 years 5 MAXIMUM The time necessary for restoration of the ecological system ( the soil or groundwater)> 5 years Figure 4. Severity rating scale environmental consequences of failure 4. Rating scale of severity of consequences of the failure on the human body (figure 5). 5. Rating scale consequences of failure probability (figure 6). 6. Risk assessment grid ( figure 7). 7. Scale of classification of the levels of risk/security (figure 8). 8. Assessment sheet of the working system. 9. Statement of proposed measures to avoid risk of damage of the evaluated system components. Α-573

5 SEVERITY CLASSES CONSEQUENCES SEVERITY OF THE CONSEQUENCES 1 NEGLIGIBLE Minor reversible consequences, working disability predicted up to 3 days (cure without treatment) 2 LOW Reversible consequences with a working disability foreseeable 3-45 days, requiring medical treatment 3 MEDIUM Reversible consequences with a working disability expected from days, requiring medical treatment and hospitalization 4 SERIOUS Irreversible consequences with loss of working capacity between %, degree of disability I-III 5 MAXIMUM Death Collective labor accidents or occupational diseases Figure 5. Rating scale of severity of consequences of the failure on the human body PROBABILITY CLASSES EVENTS PROBABILITY OF THE CONSEQUENCES (frequency of probable generation of the consequences) 1 EXTREMELY RARE extremely low P > 5 years 2 VERY RARE very low 2 years < P < 5 years 3 RARE low 1 year < P < 2 years 4 FREQUENTLY medium 1 month < P < 1 year 5 VERY FREQUENTLY Very high P < 1 month Figure 6. Rating scale consequences of failure probability Accepted level of global risk is 2,5. Condition (Băbu, 2007): N r N a (N r - Calculated level of global risk; N a - Accepted level of global risk). Accepted level of global security is 2,5. Condition: N s N sa (N s -Calculated level of global security; N sa - Accepted level of global security). Α-574

6 PROBABILITY CLASSES EXTREMLYR ARE VERY RARE RARE FREQUENT VERY FREQUENT SEVERITY CLASSES CONSEQUENCES P > 5 years 2 years < P < 5 years 1 year < P < 2 years month < P < 2 years P < 1 year 5 MAXIMUM (5,1) (5,2) (5,3) (5,4) (5,5) 4 SERIOUS (4,1) (4,2) (4,3) (4,4) (4,5) 3 MEDIUM (3,1) (3,2) (3,3) (3,4) (3,5) 2 LOW (2,1) (2,2) (2,3) (2,4) (2,5) 1 NEGLIGIBLE (1,1) (1,2) (1,3) (1,4) (1,5) Figure 7. Risk assessment grid RISK LEVEL SEVERITY-PROBABILITY TORQUE SECURITY LEVEL 1 MINIMUM (1,1) (1,2) (1,3) (1,4) (1,5) (2,1) 5 MAXIMU M 2 LOW (2,2) (2,3) (2,4) (3,1) (3,2) (4,1) 4 HIGH 3 MEDIUM (2,5) ( (3,3) (3,4) (4,2) (5,1) 3 MEDIUM 4 HIGH (3,5) (4,3) (4,4) (5,2) (5,3) 2 LOW 5 MAXIMUM (4,5) (5,4) (5,5) 1 MINIMUM Figure 8. Scale of classification of the levels of risk/security Assessment sheet of the working system is summary document of all the operations for identifying and assessing the risks of failure on the four categories namely: environmental impact; safety and health of the workers. Α-575

7 This form includes (Băbu, 2007): identification data of the analyzed system (plant, equipment), namely: company, department of production (studio) ; identification of assessors: name, function; generic components of the analyzed system; nomination identified risk factors; explicit forms of manifestation of specific risk factors identified (description, parameters and functional characteristics, etc.); maximum foreseeable consequence of the risk factors identified; class severity and probability forecast; risk level; Overall risk level (N r ) for a system (plant, equipment, etc.) is calculated as a weighted average of risk levels (R i ) established risk factors identified. For the result to reflect reality as accurately as possible, be used as an element of risk factor weighting rank (r i ), which is equal to the risk level. The formula for calculating the overall risk level is as follows (Alexandru, 2007): N = r n i i=1 n i=1 r.r r i i (1) Security level (N s ) on job classification scale to identify levels of risk / safety. The overall level of risk and security level entered in the System work evaluation sheet. To establish the necessary measures to improve safety at work system should be analyzed considering the hierarchy of risks assessed, according to the scale of employment levels of risk/safety aspects, in order (Alexandru,2007): 5 1 if operating with risk levels; 1 5 if operating with security levels; Proposed measures will be included in Preventive measures proposed sheet. 3. CONCLUSIONS Implement a process of risk-based maintenance is a complex process involving: - acquisition of a specialized computer program which has different modules according to the groups of machines and equipment used in production process; - purchase of specialized tools and nondestructive test apparatus such as those based on analysis of vibration or thermographs; - specializing and training of the maintenance personnel; - existence of databases and electronic catalogs on the draft technical drawings of parts for all equipment and plant production process; - the existence of records on computer and automatic acquisition, consumption and stock parts. Therefore, implementing a process of risk-based maintenance is a costly process, which few companies in Romania now afford to allocated for implementation of a maintenance process, even if the benefits can be large in a relatively short time. Calling external specialist services is also very expensive, the evaluation of a facility once costing between to euros. In the present study we sought to find a method for assessing the risk of failure of technological facilities for pulp and paper industry and assessment of the consequences of these failures. Α-576

8 The proposed risk assessment method and reported in the paper is inexpensive, accessible and easy to implement by maintenance professionals in any enterprise producing pulp and paper from Romania or from other sectors. ACKNOWLEDGMENT This paper was supported by the project "Doctoral studies in engineering sciences for developing the knowledge based society-sidoc contract no. POSDRU/88/1.5/S/60078, project co-funded from European Social Fund through Sectorial Operational Program Human Resources REFERENCES 1. Alexandru I., (2007), Metode de evaluare a riscurilor, Universitatea Tehnică Gheorghe Asachi, Iaşi. 2. Barratt M., (2005), Risk based inspection, SKF Technology Conference, San Diego, SUA. 3. Băbuţ G., (2007), Metode de evaluare a riscurilor profesionale, Universitatea Petroşani. 4. Fulop I., Gyenge Cs., Fulop D, and Barisic B, (2009), Some practical aspects of Risk Based Maintenance implementation in paper industry, 9 th MTeM International Conference, Cluj-Napoca. 5. Wintle J.B.,Kenzie B.W., Amphlett G.J., and Smalley S., (2001), Best practice for risk based nspection as a part of plant integrity management, TWI and Royal &SunAlliance Engeneering for the Health and Safety Executive. Α-577