INHERENTLYINHERENTLYSAFER PROCESSSAFER PROCESSDESIGN PRINCIPLESDESIGN PRINCIPLES

Paul Amyotte, Christian Paul Amyotte, Christian Etowa Etowa and Mike and Mike PeggPeggDepartment of Chemical Department of Chemical EngineeringEngineeringDalhousie UniversityDalhousie University

or…INHERENT SAFETYor…INHERENT SAFETYIt May Be Common Sense, It May Be Common Sense, But Is ItBut Is ItCommon Knowledge?Common Knowledge?

PSM SymposiumPSM Symposium5151stst Canadian Chemical Canadian Chemical Engineering ConferenceEngineering ConferenceHalifax, Nova ScotiaHalifax, Nova Scotia

OUTLINEOUTLINE

•• Inherent SafetyInherent Safety–– What is it?What is it?

•• Inherent SafetyInherent Safety–– How can we apply this concept?How can we apply this concept?–– Examples from several fieldsExamples from several fields

•• Concluding RemarksConcluding Remarks•• QuestionsQuestions

INHERENT SAFETYINHERENT SAFETYWhat is it?What is it?

•• What was your first form of What was your first form of “pedal power” transportation?“pedal power” transportation?–– What was your next?What was your next?–– Why?Why?

•• As people grow older, they may As people grow older, they may wish to live in a onewish to live in a one--story house story house instead of a twoinstead of a two--story house.story house.–– Why?Why?

INHERENT SAFETYINHERENT SAFETYWhat is it?What is it?

•• From the dictionary From the dictionary -- InherentInherent–– belonging to the very nature of a belonging to the very nature of a

person or thingperson or thing–– stresses the inseparability of a stresses the inseparability of a

part, element, or qualitypart, element, or quality

How We Deal With How We Deal With HazardsHazards•• Engineered Safety:Engineered Safety: Engineering Engineering

features which reduce frequency or features which reduce frequency or mitigate consequences of existing mitigate consequences of existing hazardshazards

•• Procedural Safety:Procedural Safety: Established Established operating procedures for controlling operating procedures for controlling existing hazardsexisting hazards

•• Inherent Safety:Inherent Safety: Characteristics of a Characteristics of a design which prevent hazards or design which prevent hazards or mitigate consequencesmitigate consequences

Engineered SafetyEngineered Safety

Procedural SafetyProcedural Safety

Inherent SafetyInherent Safety

•• Minimize (Intensify)Minimize (Intensify)–– Minimize the amount of hazardous Minimize the amount of hazardous

material that is in usematerial that is in use

Inherent SafetyInherent Safety

•• SubstituteSubstitute–– Substitute less hazardous Substitute less hazardous

materials and processes wherever materials and processes wherever possiblepossible

Inherent SafetyInherent Safety

•• Moderate (Attenuate)Moderate (Attenuate)–– Moderate the process conditions of Moderate the process conditions of

the hazardous materialsthe hazardous materials

Inherent SafetyInherent Safety

•• SimplifySimplify–– Simplify the equipment and Simplify the equipment and

processes that are usedprocesses that are used

Inherent SafetyInherent Safety

•• Not so much a principle of Not so much a principle of inherent safety, but more when inherent safety, but more when to apply the principlesto apply the principles–– Make changes EARLYMake changes EARLY

CHEE 4773 IndustrialCHEE 4773 IndustrialSafety & Loss ManagementSafety & Loss Management

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

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

Hazard IdentificationHazard Identification•• Preliminary Hazard Analysis (PHA)Preliminary Hazard Analysis (PHA)

–– Good time to consider inherent safetyGood time to consider inherent safety•• Checklist (CL)Checklist (CL)•• WhatWhat--If? (WI?)If? (WI?)•• WhatWhat--If?/Checklist (WI?/CL)If?/Checklist (WI?/CL)•• Failure Modes and Effects Analysis Failure Modes and Effects Analysis

(FMEA)(FMEA)•• Hazard and Operability Study Hazard and Operability Study

(HAZOP)(HAZOP)•• Fault Tree (FT)Fault Tree (FT)•• Event Tree (ET)Event Tree (ET)

PHA With Inherent PHA With Inherent Safety ConsiderationsSafety Considerations

PHA With Inherent PHA With Inherent Safety ConsiderationsSafety Considerations

Use of ChecklistsUse of Checklists

DOWDOWFire & Explosion IndexFire & Explosion Index

DOWDOWFire & Explosion IndexFire & Explosion Index

INHERENT SAFETYINHERENT SAFETYHow can we apply this concept?How can we apply this concept?

•• We need to consider inherent safety We need to consider inherent safety early in our safety thinking. We need early in our safety thinking. We need to consider inherent safety as a to consider inherent safety as a complement to, or substitute for, complement to, or substitute for, engineered and procedural safety.engineered and procedural safety.–– Process EngineeringProcess Engineering–– Design ApplicationsDesign Applications–– Occupational Health & SafetyOccupational Health & Safety–– General Loss PreventionGeneral Loss Prevention

ProcessProcessEngineeringEngineering•• CASE STUDIESCASE STUDIES•• Bhopal, IndiaBhopal, India

–– Union Carbide plant; 1984Union Carbide plant; 1984–– MethylMethyl isocyanateisocyanate

•• EPA Chemical Accident Investigation ReportEPA Chemical Accident Investigation Report–– Ethylene oxide explosion (Accra Pac facility; Ethylene oxide explosion (Accra Pac facility;

Elkhart Indiana; 1997)Elkhart Indiana; 1997)–– Locating the reclamation tank, which holds Locating the reclamation tank, which holds

up to 20 pounds of ethylene oxide, inside the up to 20 pounds of ethylene oxide, inside the Gas House violates good industry practice Gas House violates good industry practice for for MINIMIZINGMINIMIZING the quantity of hazardous the quantity of hazardous material in an occupied area.material in an occupied area.

•• IChemE Training PackageIChemE Training Package–– Filling chlorine cylinders Filling chlorine cylinders

DesignDesignApplicationsApplications•• Change early!Change early!

–– Of course, this forces you to consider Of course, this forces you to consider hazard analysis and to make decisions hazard analysis and to make decisions early in the design processearly in the design process

–– CarryCarry--on on vs vs checkcheck--in luggagein luggage•• EmailEmail

–– Attach File to New MessageAttach File to New Message–– Send ImmediatelySend Immediately

•• Sliding glass doors at Montreal Sliding glass doors at Montreal ((DorvalDorval) airport () airport (SIMPLIFYSIMPLIFY))

OccupationalOccupationalHealth & SafetyHealth & Safety•• D.L. D.L. GoetschGoetsch, , The Safety and Health The Safety and Health

HandbookHandbook, Prentice, Prentice--Hall, NJ (2000) Hall, NJ (2000) 213213--215.215.

•• Violence in the workplace Violence in the workplace -- risk risk reduction strategiesreduction strategies

•• Access control, policies, training, Access control, policies, training, etc.etc.

•• Natural surveillanceNatural surveillance–– Involves designing, arranging and Involves designing, arranging and

operating the workplace in a way that operating the workplace in a way that MINIMIZESMINIMIZES secluded areassecluded areas

OccupationalOccupationalHealth & SafetyHealth & Safety•• M. Hodgson, M. Hodgson, Engineered Noise Control Engineered Noise Control --

At the SourceAt the Source, OHS Canada, Vol. 17, No. , OHS Canada, Vol. 17, No. 2 (March 2001) 242 (March 2001) 24--28.28.

•• Hearing protection is not the only Hearing protection is not the only -- or or even the besteven the best-- solution to the problem solution to the problem of noise induced hearing loss.of noise induced hearing loss.

•• Controlling transmission involves Controlling transmission involves MODIFYINGMODIFYING the paths by which airborne the paths by which airborne sound and structuresound and structure--borne vibration borne vibration energy propagates from the point of energy propagates from the point of generation toward external surfaces.generation toward external surfaces.

GeneralGeneralLoss PreventionLoss Prevention•• Facilities Renewal Strategy, Facilities Renewal Strategy,

DalhousieDalhousie–– Increase spending on facilities renewal Increase spending on facilities renewal

from internal and external sourcesfrom internal and external sources–– Lobby government for earLobby government for ear--marked marked

fundingfunding–– Portion of new overhead to facilities Portion of new overhead to facilities

renewalrenewal–– Fundraising for facilities renewalFundraising for facilities renewal–– BoGBoG approve new facilities construction approve new facilities construction

only if satisfied that maintenance and only if satisfied that maintenance and operations cost of the new facility have operations cost of the new facility have been provided for...been provided for...

GeneralGeneralLoss PreventionLoss Prevention•• Calgary TowerCalgary Tower•• August 2000; about a weekAugust 2000; about a week

before the Moscow TVbefore the Moscow TVtower firetower fire

•• Yes, it has two restaurantsYes, it has two restaurantsand a flame on the top. But isand a flame on the top. But isit really necessary to allow smoking it really necessary to allow smoking in that isolated a location?in that isolated a location?

•• How about considering How about considering MINIMIZATIONMINIMIZATION of uncontrolled of uncontrolled ignition sources?ignition sources?

GeneralGeneralLoss PreventionLoss Prevention•• Swissair Flight 111 (Mail Star, Dec 5, Swissair Flight 111 (Mail Star, Dec 5,

2000)2000)•• Engineered:Engineered:

–– Adoption of smoke and odour detectors Adoption of smoke and odour detectors in more areas of airplanesin more areas of airplanes

•• Procedural:Procedural:–– Any smoke or odour considered an Any smoke or odour considered an

emergency that may require landing emergency that may require landing immediatelyimmediately

–– Standard troubleshooting checklistsStandard troubleshooting checklists

GeneralGeneralLoss PreventionLoss Prevention

•• Swissair Flight 111 (Mail Star, Swissair Flight 111 (Mail Star, Dec 5, 2000)Dec 5, 2000)

•• Inherent:Inherent:–– FAA orders FAA orders metallized metallized Mylar Mylar

blanket insulation replaced, calling blanket insulation replaced, calling it fairly flammable (it fairly flammable (SUBSTITUTESUBSTITUTE))

–– FAA bans inFAA bans in--flight entertainment flight entertainment system (system (MINIMIZEMINIMIZE))

GeneralGeneralLoss PreventionLoss Prevention•• OH&S Update, OH&S Update, Parks Canada to Appeal Parks Canada to Appeal

SidearmsSidearms RulingRuling, OHS Canada, Vol. 17, , OHS Canada, Vol. 17, No. 3 (April/May 2001) 6.No. 3 (April/May 2001) 6.

•• Complaint filed that Parks Canada’s “noComplaint filed that Parks Canada’s “no--sidearmssidearms” policy constituted a safety ” policy constituted a safety hazard for wardenshazard for wardens

•• Parks Canada directed to Parks Canada directed to –– Correct hazard or condition or alter law Correct hazard or condition or alter law

enforcement activities of the wardens, orenforcement activities of the wardens, or–– Protect wardens from the dangerProtect wardens from the danger

•• Parks Canada complied by pulling Parks Canada complied by pulling national park wardens off law national park wardens off law enforcement activities (over to RCMP)enforcement activities (over to RCMP)

GeneralGeneralLoss PreventionLoss Prevention•• Metro Spends Millions Sorting Metro Spends Millions Sorting

Slackers’ Trash (Mail Star, February Slackers’ Trash (Mail Star, February 10, 2000)10, 2000)

•• Otter Lake landfill facilityOtter Lake landfill facility•• No one opens up the bags and pulls No one opens up the bags and pulls

out the goopy, gross stuff...it’s all out the goopy, gross stuff...it’s all done by machine.done by machine.

•• Education campaign imminent, Education campaign imminent, including curbside monitoringincluding curbside monitoring

•• Friendly advance man on collection Friendly advance man on collection days; talk facedays; talk face--toto--face with residentsface with residents

GeneralGeneralLoss PreventionLoss Prevention•• Dead Pets, Wallets End Up At Landfill Dead Pets, Wallets End Up At Landfill

(Mail Star, February 10, 2000)(Mail Star, February 10, 2000)•• Otter Lake landfill facilityOtter Lake landfill facility•• To protect workers from biomedical To protect workers from biomedical

wasteswastes–– Trained for a week in sorting procedures; Trained for a week in sorting procedures;

only pick up what they can seeonly pick up what they can see–– Immunized against hepatitis B (+ tetanus Immunized against hepatitis B (+ tetanus

shot)shot)–– Third measure is preventive; if ID Third measure is preventive; if ID

possible, send letter on proper disposal possible, send letter on proper disposal to residentto resident

GeneralGeneralLoss PreventionLoss Prevention•• Peter Peter Mansbridge Mansbridge (June 27, 2001); re. (June 27, 2001); re.

banning of cell phone use while banning of cell phone use while driving (NY state); three journalistsdriving (NY state); three journalists

•• Ottawa: Education is key Ottawa: Education is key ((proceduralprocedural))

•• Montreal: HandsMontreal: Hands--free devices free devices ((engineeredengineered))

•• St. John’s: Pull over to side of road St. John’s: Pull over to side of road ((inherentinherent))

CONCLUDINGCONCLUDINGREMARKSREMARKS

•• Inherent SafetyInherent Safety–– Characteristics of a design which Characteristics of a design which

prevent prevent hazards or mitigate hazards or mitigate consequencesconsequences

•• It It isis common sense.common sense.•• It will not be common knowledge It will not be common knowledge

until it is until it is namednamed and and routinely routinely consideredconsidered along with engineered along with engineered and procedural safety features.and procedural safety features.

QUESTIONSQUESTIONS•• Are there regulatory issues?Are there regulatory issues?•• Are the benefits clear (e.g. plant size Are the benefits clear (e.g. plant size

and cost)?and cost)?•• What are the barriers to What are the barriers to

implementation (e.g. resistance to implementation (e.g. resistance to change)?change)?

•• What tools are needed (e.g. What tools are needed (e.g. qualitative, quantitative, indices)?qualitative, quantitative, indices)?

•• http://www.lboro.ac.uk/departments/http://www.lboro.ac.uk/departments/cg/cg/isdisd/index./index.htmhtm