Occupational Safety and Health 5

Safety: Strategy of Accident Prevention

Loss Prevention: Prevention of accidents

which result in injury to humans, damage to

the environment, loss of production, damage

to equipment, or loss of inventory as well as

to protect company reputation and bussiness.

Definitions

Occupational Safety and Health 6

Ammonium Nitrate Explosion in

Toulouse - France

21 September 2001

• 31 People Killed

• 2442 Injured

• Losses in Hundreds of

millions dollars

Occupational Safety and Health 7

Regulatory Concerns

OSHA - Occupational Safety and Health Administration

Force of law with respect to on-site workplace hazards / accidents.

OSHA 1910.119 - Process Safety Management

- Must identify hazards

- Must train and certify workers

- Safe work system

- Management of Change

- Accident investigations

- Process Info / Documentation

- Contractor safety

- Operating procedures

- Mechanical integrity

- Others

Hazard

Hazard adalah suatu kondisi dimana secara kimia ataupun fisik yang memiliki potensi dapat membahayakan terhadap manusia, properti maupun lingkungan

Hazard Evaluation/ Evaluasi bahaya adalah suatu usaha yang terorganisir untuk mengidentifikasi dan menganalisa situasi yang berbahaya dan signifikan serta terasosiasi dengan sebuah proses atau aktifitas. Evaluasi Bahaya ini digunakan untuk menunjukkan dengan tepat kelemahan dalam suatu rancangan dan operasional dari fasilitas yang dapat menyebabkan terilisnya bahan berbahaya, kebakaran maupun terjadinya ledakan.

• Process hazard(s) analysis • Hazard and risk analysis • Process hazard(s) review • Hazard assessment • Hazard identification and • Predictive hazard evaluation

• Process safety review • Process risk survey • risk analysis • Process risk review . • Hazard study

Proses Safety Management (PSM) :

1 • Identifikasi hazard

2

• Pemilihan teknik Hazard Evaluation yang tepat sesuai kebutuhan

3 • Penggunaan Metode Tertentu

4 • Penindaklanjutan hasil Hazard Evaluation

Evaluasi bahaya biasanya fokus pada penyebab potensial dan konsekuensi dari peristiwa episodik, seperti kebakaran, ledakan, dan rilis yang tidak direncanakan dari bahan berbahaya

Aspek Aspek dari Pemahaman Resiko

Implementasi program PSM dapat membantu organisasi memanage resiko pada seluruh fasilitasnya sepanjang umur perusahaannya. Pengembangan untuk pemahaman dari resiko membutuhkan 3 pertanyaan spesifik seperti terangkum dalam diagram berikut :

Elements of process incidents

Anatomy of a catastrophic incident

Dalam kondisi operation mode “Normal” semua proses hazards aman dan terkendali dan fasilitas beroperasi dalam batasan dan sesuai dengan prosedur operasi yang ada

Penyebab awal atau initiating cause merupakan suatu bentuk perlaihan mode operasi dari kondisi normal menjadi abnormal. Dalam konteks prosedur evaluasi bahaya, ini modus yang abnormal ini disebut deviasi

Key Concept : The Loss Event

“Loss Event” adalah suatu periode tertentu di dalam “incident sequence” dimana kejadian fisik yang tidak diperbaiki atau “irreversible physical event” terjadi dan mempunyai potensi kehilangan dan akibat yang fatal.

Untuk mempermudah identifikasi initiating cause dan loss event’ dapat dituangkan dalam insident sequence seperti gambar berikut :

Initiating cause adalah transisi dari mode operasi Normal ke Abnormal dan Loss Event adalah transisi dari mode operasi Normal ke Emergency.

The Role of Safeguards

Dalam konteks prosedur evaluasi hazard, setiap perlatan, sistem maupun tindakan yang dapat mencegah rantai kejadian (chain of event) yang setelah adanya initiating cause disebut Safeguard.

Hazard

• Hazards are contained by multiple protective barriers

• Barriers may have weaknesses or ‘holes’

• When holes align hazard energy is released, resulting in the potential for harm

• Barriers may be physical engineered containment or behavioral controls dependent on people

• Holes can be latent/incipient, or actively opened by people

Accident

Protective

‘Barriers’

Weaknesses

Or ‘Holes’

HAZARD PROTECTION

Protective and Responsive Protection

1

2

4

56

3

PREVENTION

BARRIERSRECOVERY

BARRIERS

LocationTop Event(eg Loss of

Containment)

ConsequenceCondensate pool on water

(Environmental Spill)

Barrier (eg High Level Trip)

Barrier (eg PSV)

Barrier (eg Designed to

Code)

Threat

(eg Slugging)

Threat

(eg Blocked Outlet)

Threat

(eg Corrosion)

Hazard

(eg Condensate)

Location

Top Event

(eg Loss of

Containment)

Barrier (eg Ignition Control)

Barrier (eg Fire Detection &

ESD)

Barrier (eg Bund)

Consequence

(eg Unignited

Condensate release)

Consequence

(eg Fire [Spray/Pool/

Flash] & Explosion)

Consequence

(eg Condensate Pool

– Environmental Spill)

19

• In modern plants,

process safety relies

on the principle of

multiple protection

layers; Typical

layers of protection

in a modern

chemical plant .

• Each layer of

protection consists

of a grouping of

equipment and/or

human actions,

shown in the order

of activation.

Multiple Protection

Layers

Onsite Risk Criteria

10-3 per year

10-5 per year

Hazard Evaluation Throughout a Plant Lifetime

Dua aspek evaluasi bahaya selama masa hidup plant/pabrik • Dengan menggunakan pendekatan life cycle dalam hubungan dengan kegiatan

Process safety management (PSM) lainnya secara efisien dapat mengungkapkan kekurangan dalam desain dan operasi sebelum unit ini ditempatkan, dibangun atau dioperasikan, sehingga membuat penggunaan sumber daya menjadi efektif yang ditujukan untuk menjamin keaman dan produktifitas dari fasilitas.

• Terlepas dari teknik yang digunakan untuk melakukan evaluasi bahaya sepanjang masa operasi fasilitas, masing-masing studi, bersama dengan informasi yang didokumentasikan dan asumsi, harus diperbarui atau divalidasi ulang secara periodik

Semua pendekatan process safety management (PSM) secara konsisten mengacu pada : “Evaluasi hazard harus dilakukan sepanjang umur dari fasilitas”. Hazard evaluation dimulai sejak • Tahap Research and Development • Detailed rancangan dan konstruksi • Selama commisioning dan start up • Secara periodik sepanjang usia operasi • Sampai proses dihentikan.

Proccess Safety Overview

1.What is process safety?

2. Opposite of process safety : Major incidents

3. The anatomy of process safety incidents

4. Oveview of process safety strategies

5. Taking advantage of past experience

6. Defense in depth/layers or protection

7. Elements of process safety management

Process Safety

the absence of loss and harm resulting from fires, explosions and hazardous material releases at process facilities.

The absence of loss and harm at process facilities by:

(a). Identifying process hazards,

(b). Containing and controlling them

(c). Countering abnormal situations with effective safeguards

Major Process incidents

Flixbrough,UK (June 1974)

• Partial oxidation of cyclohexane

• Catastrophic failure of temporary piping

• 30 tonnes of ht cyclohexane released in 30 s

• Vapor cloud explosion

• 28 fatalities, 53 injuries, 1.800+houses damaged;plant destroyed

• 18 of those fatally injured were in control room

• Hastened passage of UK “Healthy and Safety at Work Act”

See CCPS 2008b for details of these incidents

MAJOR PROCESS INCIDENTS

Incident - Definition

Incident: An unplanned event or sequence of events that either resulted in, or had the potential to result in, adverse impacts.

Process safety incident anatomy

Process Industry Incidents

Fires - Fatalities

Explosions - Injuries

Toxic releases - Environ. Damage

- Property Damage

- Evacuations

- Business Losses

- Plant Closings

- fines, Lawsuits

Process Industry Incidents

Loss - Fatalities Events - Injuries

- Environ.Damage

- Property Damage

- Evacuations

- Business Losses

- Plant Closings

- Fines, Lawsuits

Process industry incidents

Loss Events

Impact

Key definition

Loss event:

Point in time in an abnormal situation when an irreversible physical event occurs that has the potential for loss and harm impacts.

Point in time in an abnormal situation when an irreversible physical event occurs that has the potential for loss and harm impacts.

Examples :

Hazardous material release

Flammable vapor or.dust cloud ignition

Tank or vessel overpressurization ruptur

Key questions Why do loss events happen? How do loss events happen? What must be done to avoid them?

Why do loss events happen?

We choose to handle dangerous process materials and energies

• To make a living • To provide society with desiable

product As long as we choose to handle

them, a potential for loss events exitss

Process safety

The absence of loss and harm at process facilities by (a) Identifying process hazards, (b) Containing and controlling them, (c) Countering abnormal situations with effective

safeguards

Process hazard - definition

Presence of a stored or connected material or energy with inherent characteristics having the potential for causing loss or harm

3 types of process hazards

Material hazards

Energy hazards

Chemical interaction hazards

3 types of process hazards

Material hazards : A contained or connected process material with one more hazardous characteristics

Energy hazards : some form of physical energy contained within or connected to the process with the potential for loss or harm

Chemical interaction hazards : presence or material with the potential for loss or harm upon their interaction in an unintentional or uncontrolled manner

Inherent characteristics

Presence of a stored or connected material or energy with inherent characteristics having the pootential for causing loss or harm

Material hazards

Inherently hazardous characteristics :

Flammability Insability

Toxicity Corrosivity

Flammable materials

Inherent characteristics : > Flash point ( volatility) > Heat of combustion > Ease of ignition . Flammability ignition limits . Minimum ignition energy . Autoignition temperature

Limitations

NFPA 704 diamonds and SDSs only give properties of individual hazardous materia

. Hazardous energies not identified . Some hazardous chemical interactions not identified . Connected hazards may not be identified

Process hazard

Presence of a stored or connected material or energy with inherent characteristics having the pootential for causing loss or harm

process hazard

Presence of a stored or connected material or energy with inherent characteristics having the pootential for causing loss or harm

Degree of hazard

More hazardous material

greater degree of hazard

farther from zero energy state

greater degree of hazard

Key questions

Why do loss events happen? How do loss events happen? What must be done to avoid them?

How do loss events happen?

Anatomy of an incident

Unsafe act & condition precursors

Incident sequence : Hazard

During normal operation,

all hazards are contained

and controlled

Normal operation

During normal operation,

all hazards are contained

and controlled , but they

are still present.

Incident sequence : cause Every incident start with an initiating cause (also called an initiating event or just a “cause”.

Example initiating cause:

- feed pump fails off

- procedural step omitted

- truck runs into process piping

- wrong raw material is received

- extreme low ambient temperature

Once an initiating cause accurs, normal operation cannot continue without a process or operational response.

Incident sequence : Deviation

The immediate result of an initiating cause is a deviation

Abnormal situations Most engineering focuses on designing a process to work : (normal situation) We must also consider how a process can fail , starting with an “abnormal situation”

Incident sequence : Deviation

A deviation is an abnormal situation, outside defined design or operational parameter.

Incident sequence : Loss event A loss event will result if a deviation continues uncorrected and the process is not shut down

Loss events are generally irreversible process material/energy reases.

Incident sequence : Impacts Impacts are the losses and injuries that can result from a loss event.

There are often other less tangible impacts as well

Incident sequence without safeguards

How do loss events occur?

Anatomy of an Incident

Unsafe act & condition precursors

Unsafe act & condition precursors

Pyramid principle of safey

Pyramid principle of safety

Pyramid principle of safety

Process safety Overview 1.What is process safety? 2.Opposite of process safety : Major incident 3.The anatomy of process safety incidents 4.Overview of process safety strategies 5.Taking advantage of past experience What 6.Defence in depth/layers of protection must be 7. Elements of process safety management done

Process safety Overview

1.What is process safety?

2.Opposite of process safety : Major incident

3.The anatomy of process safety incidents

4.Overview of process safety strategies

Using past experience “Those who cannot remember the past are condemned to repeat it.”- George Santayana Learnings from past (usually bad) experiences have been

embodied in various forms: Regulations - Handbooks Codes - Guidelines Industry standards - Procedures Company standards - checklists “”Best practices” - Supplier Recommendations

RAGAGEPs Recognized and Generally Accepted Good Engineering Practices • Take advantage of wealth of experience • Pass on accumulated knowledge • Reduce recurrence of past incidents • Enable uniformity of experience of expectations • Reduce liabilities when followed

Example : Anhydrous ammonia Regulatory requirements : E.g. U.S.OSHA Standard 29 CFR 1910.111. “Storage and Handling of Anhydrous Ammonia” Industry standards CGA G-2.”Anhydrous Ammonia” ANSI/CGA K61.1.”American National Standard Safety requirement for the Storage and Handling of Anhydrous Ammonia” Other standards apply to specific applications,e.g.,EN 378 for ammonia

refrigeration

Layers of protection Also called “safety layers” Multiple layers may be needed.since no protection is

100%reliable Each later must be designed to be effective Each layer must be maintained to be effective some layer of protection are contain and control

measures Other layers of protection are safeguards

Layers of protection Also called “safety layers” Multiple layers may be needed.since no protection is

100%reliable Each later must be designed to be effective Each layer must be maintained to be effective Some layer of protection are contain and control

measures Other layers of protection are safeguards

Key definition

Safeguard: Any device ,system, or action that would likely interrupt the chain of events following an initiating cause or that would mitigate loss event impacts/

Process safety Overview 1.What is process safety?

2.Opposite of process safety : Major incident

3.The anatomy of process safety incidents

4.Overview of process safety strategies

5.Taking advantage of past experience

6.Defence in depth/layers of protection

7. Element of process safety management

Comprehensive PSM program elements

Management systems

Employee participation

Process safety information

Process hazard analysis

Operating precedures

Training

Contractor safety

• Pre-startup safety reviews

• Mechanical integrity

• Safety work practies

• Management of change

• Emergency planning and response

• Incident investigation

• Compliance audits

PSM elements covered in this course

Management systems

Employee participation

Process safety information

Process hazard analysis

Operating precedures

Training

Contractor safety

• Pre-startup safety reviews

• Mechanical integrity

• Safety work practies

• Management of change

• Emergency planning and response

• Incident investigation

• Compliance audits