CHE 4284/5292 Industrial Safety Accident and Loss Statistics Concepts and Formulas

Transcription

1 Safety or Loss Preventon: s the preventon of accdents by the use of approprate technologes to dentfy the hazards of a chemcal plant and to elmnate them before an accdent occurs. Hazard: s anythng wth the potental for producng an accdent. Rsk: s the probablty of a hazard resultng n an accdent. Safety Programs: The mplementaton of a successful safety program requres several ngredents: 1. Safety knowledge, 2. Safety experence, 3. Techncal competence, 4. Safety management support, 5. Commtment. Good Safety Program: s one that dentfes and elmnates exstng safety hazards. Outstandng Safety Program: has the management systems whch prevent the exstence of safety hazards. Engneerng Ethcs: The engneer has the responsblty to hm/herself, fellow workers, colleagues, famly, frends, communty and the engneerng professon. Engneers shall uphold and advance the ntegrty, honor, and dgnty of the engneerng professon. Accdent and Loss Statstcs: These are mportant measures of the effectveness of Safety Programs. These statstcs are valuable for determnng f a process s safe or f a safety procedure s workng effectvely. Statstcal Methods: report the number of accdents and/or fataltes for a fxed number of workers durng a specfc perod. The Statstcal Methods to be consdered are: 1. OSHA Incdence Rate 2. Fatal Accdent Rate (FAR) 3. Fatalty Rate or deaths per person per year 1. OSHA Incdence Rate (OSHA IR): (OSHA, Occupatonal Safety and Health Admnstraton) Ths method s dependent on the number of exposed hours. Based on cases per 100 worker year. A worker year s assumed to contan 2000 hours (50 work weeks/year x 40 hours/week) Based on 200,000 hours of worker exposure to hazard. It can be calculated based on the followng equatons: OSHA Incdence Rate (OSHA IR): (Based on njures and llness) OSHA Incdence Rate (Based on njures and llness) = Number of njures and llnesses x 200,000 Total hours worked by all employees durng perod covered OSHA Incdence Rate (OSHA IR): (Based on lost workdays) OSHA Incdence Rate (Based on lost workdays) = Number of lost workdays x 200,000 Total hours worked by all employees durng perod covered

2 2. Fatal Accdent Rate (FAR): Ths method s mostly used n the Brtsh Chemcal Industry. Ths method s dependent on the number of exposed hours. Reports the number of fataltes based on 1000 employees workng ther entre lfetme. The employees are assumed to work at total of 50 years. FAR s based on 10 8 workng hours. FAR = Number of fataltes x 10 8 Total hours worked by all employees durng perod covered 3. Fatalty rate or deaths per person per year: Ths method s ndependent of the number of hours actually worked. Reports only the number of fataltes expected per person per year. Fatalty Rate = Number of fataltes per year Total number of people n applcable populaton TABLE 1-2: A GLOSSARY OF TERMS USED BY OSHA TO REPRESENT WORK RELATED LOSSES: OCCUPATIONAL INJURY s any njury such as a cut, fracture, spran, amputaton, etc., whch results from a work accdent or from an exposure nvolvng a sngle ncdent n the work envronment. OCCUPATIONAL ILLNESS of an employee s any abnormal condton or dsorder, other than one resultng from an occupatonal njury caused by exposure to envronmental factors assocated wth employment. It ncludes acute and chronc llnesses or dseases whch may be caused by nhalaton, absorpton, ngeston, or drect contact. LOST WORKDAYS are those days whch the employee would have worked but could not because of occupatonal njury or llness. The number of lost workdays should not nclude the day of njury or onset of llness. The number of days ncludes all days (consecutve or not) on whch, because of njury or llness (1) the employee would have worked but could not or (2) the employee was assgned to a temporary job, or (3) the employee worked at a permanent job less than full tme, or (4) the employee worked at a permanently assgned job but could not perform all dutes normally connected wth t. RECORDABLE CASES are those nvolvng an occupatonal njury or occupatonal llness, ncludng deaths. Not recordable are frst ad cases whch nvolve onetme treatment and subsequent observaton or mnor scratches, cuts, burns, splnters, etc., whch do not ordnarly requre medcal care, even though such treatment s provded by a physcan or regstered professonal personnel. NONFATAL CASES WITHOUT LOST WORKDAYS are cases of occupatonal njury or llness whch dd not nvolve fataltes or lost workdays but dd result n (1) transfer to another job or termnaton of employment, or (2) medcal treatment other than frst ad, or (3) dagnoss of occupatonal llness, or (4) loss of conscousness, or (5) restrcton of work or moton.

3 TABLE 1-3 ACCIDENT STATISTICS FOR VARIOUS SELECTED INDUSTRIES Industry OSHA Incdence Rate (Cases nvolvng days away from work and deaths) FAR (deaths/10 8 hours) Chemcal Vehcle Steel Paper 2.06 Coal Mnng Food 3.28 Constructon Agrcultural Meat Products 5.27 Truckng 7.28 TABLE 1-4 FATALITY STATISTICS FOR COMMON INDUSTRIAL ACTIVITIES Actvty Voluntary Actvty FAR (deaths/10 8 hours) Fatalty Rate (Deaths per person per year) Stayng at home 3 Travelng by Car x 10-5 Bcycle 96 Ar 240 Motorcycle 660 Canoeng 1000 Rock Clmbng x 10-5 Smokng (20 cgarettes/day) 500 x 10-5 Involuntary Actvty Struck by meteorte 6 x Struck by lghtnng (U.K.) 1 x 10-7 Fre (U.K.) 150 x 10-7 Run over by vehcle 600 x 10-7

4 CHE 4284/5292 Industral Safety Accdent and Loss Statstcs Acceptable Rsk: Every chemcal process has a certan amount of rsk assocated wth t. Rsk cannot be elmnated entrely. Publc Perceptons: The general publc has great dffculty wth the concept of acceptable rsk. The major objecton s due to the nvoluntary nature of acceptable rsk. The publc opnon and the meda put a great demand concernng safety and loss preventon n the chemcal plants. Nature of the Accdent Process: Typcal types of accdents that occur n the Chemcal Plants are: fre, exploson, and toxc release. TABLE 1-5 THREE TYPES OF CHEMICAL PLANT ACCIDENTS Type of accdent Probablty of occurrence Potental for fataltes Potental for economc loss Fre Hgh Low Intermedate Exploson Intermedate Intermedate Hgh Toxc Release Low Hgh Low Human Error: s frequently used to descrbe a cause for losses. Almost all accdents, except those caused by natural hazards, can be attrbuted to human error. The Accdent Process: Accdents follow a three step process: Intaton: The event that starts the accdent. Propagaton The event or events that mantan or expand the accdent. Termnaton The event or events that stop the accdent or dmnsh t n sze. Safety Engneerng: nvolves elmnatng the ntatng step and replacng the propagaton steps by termnaton events.

5 TABLE 1-6 DEFEATING THE ACCIDENT PROCESS Step Desred Effect Procedure Intaton Dmnsh Groundng and Bondng Inertng Exploson proof electrcal Guardrals and guards Mantenance procedures Hot-work permts Human factors desgn Process desgn Awareness of dangerous propertes of chemcals Propagaton Dmnsh Emergency materal transfer Reduce nventores of flammables Equpment spacng and layout Nonflammable constructon materals Installaton of check and emergency shut-off valves Termnaton Increase Frefghtng equpment and procedures Relef systems Sprnkler systems Installaton of check and emergency shut-off valves

6 Fatal Accdent Rate (FAR): Ths method s mostly used n the Brtsh Chemcal Industry. Ths method s dependent on the number of exposed hours. Reports the number of fataltes based on 1000 employees workng ther entre lfetme. The employees are assumed to work at total of 50 years. FAR s based on 10 8 workng hours. Plant Total FAR: FAR = TOTAL FAR Indvdual worker FAR: FAR = X FAR A Where, X Tme fracton FAR FAR of partcular process unt

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