INHERENTLY SAFER PROCESS DESIGN PRINCIPLES. Paul Amyotte, Christian Etowa and Mike Pegg Department of Chemical Engineering Dalhousie University

Transcription

1 INHERENTLY SAFER PROCESS DESIGN PRINCIPLES Paul Amyotte, Christian Etowa and Mike Pegg Department of Chemical Engineering Dalhousie University

2 or INHERENT SAFETY It May Be Common Sense, But Is It Common Knowledge? PSM Symposium 51 st Canadian Chemical Engineering Conference Halifax, Nova Scotia

3 OUTLINE Inherent Safety What is it? Inherent Safety How can we apply this concept? Examples from several fields Concluding Remarks Questions

4 INHERENT SAFETY What is it? What was your first form of pedal power transportation? What was your next? Why? As people grow older, they may wish to live in a one-story house instead of a two-story house. Why?

5 INHERENT SAFETY What is it? From the dictionary - Inherent belonging to the very nature of a person or thing stresses the inseparability of a part, element, or quality

6 How We Deal With Hazards Engineered Safety: Engineering features which reduce frequency or mitigate consequences of existing hazards Procedural Safety: Established operating procedures for controlling existing hazards Inherent Safety: Characteristics of a design which prevent hazards or mitigate consequences

7 Engineered Safety

8 Procedural Safety

9 Inherent Safety Minimize (Intensify) Minimize the amount of hazardous material that is in use

10 Inherent Safety Substitute Substitute less hazardous materials and processes wherever possible

11 Inherent Safety Moderate (Attenuate) Moderate the process conditions of the hazardous materials

12 Inherent Safety Simplify Simplify the equipment and processes that are used

13 Inherent Safety Not so much a principle of inherent safety, but more when to apply the principles Make changes EARLY

14 CHEE 4773 Industrial Safety & Loss Management Industrial safety and loss management techniques applicable to the process industries are covered. Topics include loss causation models, the roles of management and legislation, accident investigation, inspections, practices and procedures, communications, training, and emergency preparedness. Inherently safer process design and fire and explosion prevention and protection measures are described. Risk assessment is also addressed, with emphasis on the hazard identification step. Analysis of case studies is conducted throughout the course.

15 Hazard (potential for harm) vs Risk (frequency and severity)

16 Hazard Identification Preliminary Hazard Analysis (PHA) Good time to consider inherent safety Checklist (CL) What-If? (WI?) What-If?/Checklist (WI?/CL) Failure Modes and Effects Analysis (FMEA) Hazard and Operability Study (HAZOP) Fault Tree (FT) Event Tree (ET)

17 PHA With Inherent Safety Considerations

18 PHA With Inherent Safety Considerations

19 Use of Checklists

20 DOW Fire & Explosion Index

21 DOW Fire & Explosion Index

22 INHERENT SAFETY How can we apply this concept? We need to consider inherent safety early in our safety thinking. We need to consider inherent safety as a complement to, or substitute for, engineered and procedural safety. Process Engineering Design Applications Occupational Health & Safety General Loss Prevention

23 Process Engineering CASE STUDIES Bhopal, India Union Carbide plant; 1984 Methyl isocyanate EPA Chemical Accident Investigation Report Ethylene oxide explosion (Accra Pac facility; Elkhart Indiana; 1997) Locating the reclamation tank, which holds up to 20 pounds of ethylene oxide, inside the Gas House violates good industry practice for MINIMIZING the quantity of hazardous material in an occupied area. IChemE Training Package Filling chlorine cylinders

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25 Design Applications Change early! Of course, this forces you to consider hazard analysis and to make decisions early in the design process Carry-on vs check-in luggage Attach File to New Message Send Immediately Sliding glass doors at Montreal (Dorval)) airport (SIMPLIFY( SIMPLIFY)

26 Occupational Health & Safety D.L. Goetsch, The Safety and Health Handbook,, Prentice-Hall, NJ (2000) Violence in the workplace - risk reduction strategies Access control, policies, training, etc. Natural surveillance Involves designing, arranging and operating the workplace in a way that MINIMIZES secluded areas

27 Occupational Health & Safety M. Hodgson, Engineered Noise Control - At the Source,, OHS Canada, Vol. 17, No. 2 (March 2001) Hearing protection is not the only - or even the best- solution to the problem of noise induced hearing loss. Controlling transmission involves MODIFYING the paths by which airborne sound and structure-borne vibration energy propagates from the point of generation toward external surfaces.

28 General Loss Prevention Facilities Renewal Strategy, Dalhousie Increase spending on facilities renewal from internal and external sources Lobby government for ear-marked funding Portion of new overhead to facilities renewal Fundraising for facilities renewal BoG approve new facilities construction only if satisfied that maintenance and operations cost of the new facility have been provided for...

29 General Loss Prevention Calgary Tower August 2000; about a week before the Moscow TV tower fire Yes, it has two restaurants and a flame on the top. But is it really necessary to allow smoking in that isolated a location? How about considering MINIMIZATION of uncontrolled ignition sources?

30 General Loss Prevention Swissair Flight 111 (Mail Star, Dec 5, 2000) Engineered: Adoption of smoke and odour detectors in more areas of airplanes Procedural: Any smoke or odour considered an emergency that may require landing immediately Standard troubleshooting checklists

31 General Loss Prevention Swissair Flight 111 (Mail Star, Dec 5, 2000) Inherent: FAA orders metallized Mylar blanket insulation replaced, calling it fairly flammable (SUBSTITUTE( SUBSTITUTE) FAA bans in-flight entertainment system (MINIMIZE( MINIMIZE)

32 General Loss Prevention OH&S Update, Parks Canada to Appeal Sidearms Ruling,, OHS Canada, Vol. 17, No. 3 (April/May 2001) 6. Complaint filed that Parks Canada s no- sidearms policy constituted a safety hazard for wardens Parks Canada directed to Correct hazard or condition or alter law enforcement activities of the wardens, or Protect wardens from the danger Parks Canada complied by pulling national park wardens off law enforcement activities (over to RCMP)

33 General Loss Prevention Metro Spends Millions Sorting Slackers Trash (Mail Star, February 10, 2000) Otter Lake landfill facility No one opens up the bags and pulls out the goopy, gross stuff...it s all done by machine. Education campaign imminent, including curbside monitoring Friendly advance man on collection days; talk face-to to-face with residents

34 General Loss Prevention Dead Pets, Wallets End Up At Landfill (Mail Star, February 10, 2000) Otter Lake landfill facility To protect workers from biomedical wastes Trained for a week in sorting procedures; only pick up what they can see Immunized against hepatitis B (+ tetanus shot) Third measure is preventive; if ID possible, send letter on proper disposal to resident

35 General Loss Prevention Peter Mansbridge (June 27, 2001); re. banning of cell phone use while driving (NY state); three journalists Ottawa: Education is key (procedural) Montreal: Hands-free devices (engineered) St. John s: Pull over to side of road (inherent)

36 CONCLUDING REMARKS Inherent Safety Characteristics of a design which prevent hazards or mitigate consequences It is common sense. It will not be common knowledge until it is named and routinely considered along with engineered and procedural safety features.

37 QUESTIONS Are there regulatory issues? Are the benefits clear (e.g. plant size and cost)? What are the barriers to implementation (e.g. resistance to change)? What tools are needed (e.g. qualitative, quantitative, indices)? cg/isd isd/index. /index.htm