lecture 4-_hazard_analysis_prevention_and_safety_management

Topic Learning Outcome :

1. Describe the overall hazard analysis techniques.

2. Describe basic principle of risk assessment

3. Explains the safety management concern on the hazard prevention.

Topic 3 :

Hazard Analysis, prevention and safety

management

Contents :

3.1 Preliminary Hazard analysis (PHA)

3.2 Detailed Hazard analysis

3.3 Hazard Prevention and Deterrence

3.4 Safety Management concerns

Example of Hazards at Office workplace

Hazard Analysis :

• A systematic process of identifying hazards and recommending

correction action.

• 2 approaches :

Detailed

hazard

analysisPreliminary

hazard

analysis

Man Unsafe acts

Machinery Installation, layout and design of equipment

Materials Substances such as chemicals and gases use in the workplace

Method The way people carry out their work

Media Workplace condition e.g. air quality, ventilation, lighting,

noise, vibration, etc.

Source of Hazard :


• Conducted to identify potential hazards and prioritize them

according to the :

(1) probability of an accident or injury being caused by the

hazard.

(2) severity of injury, illness or property damage that could

result if the hazard caused an accident.

• PHA can serves 2 purposes :

(1) it can expedite bringing the new system on line, but at a

substantially reduced risk of injuring workers.

(2) it can serve as a guide for a future detailed analysis.

• Experience and related expertise are important factors in

conducting a preliminary review.


Example Job hazard analysis form

3.2 Detailed Hazard Analysis

• Conducted for the potential exists for serious

injury, multiple injuries or illness.

• The most widely used of these are as follow:

(1) Failure Mode and Effect of analysis (FMEA)

(2) Hazard and operability review (HAZOP)

(3) Human Error Analysis (HEA)

(4) Technic of operations review (TOR)

(5) Fault tree analysis (FTA)

(6) Risk analysis


(1) Failure Mode and Effect of analysis (FMEA)

Developed in the 1950s to determine problems that could

arise from malfunction of military system.

Is a procedure by which each potential failure and the kinds

of failures that could happen, at the component level, in the

system are examined and analyzed to determine its effect on

the system, in term of maximum potential loss.

The FMEA result are classified according to its severity.

Example FMEA form


(2) Hazard And Operability Review (HAZOP)

Developed in the 1970s by Imperial Chemical Industries Ltd

Can be defined : formal systematic critical examination of

the process and engineering intentions of new or existing

facilities to assess the hazard potential that arise from

deviation in design specifications and the consequential

effects on the facilities as a whole.

This techniques is usually performed using a set of

guidewords : NO/NOT, MORE OR/ LESS OF, AS WELL AS,…

Gained wide acceptance in the process industries as a

effective tool for plant safety and operability improvements.

E.g. on fire and explosion endpoints, toxic release.


Example HAZOP form


(3) Fault Tree Analysis (FTA)

Is an analytical method that uses a graphic model to display

the analysis process visually.

FTA is built using special symbols, some derived from Boolean

algebra.

FTA is qualitative in nature, but it can be made quantitative

by assigning “probability figure” to the various events.

However, it is rarely done because reliable probability figures

are seldom available.


(3) Fault Tree Analysis (FTA)

Symbol used in fault tree

analysis

Example of FTA.


(4) Risk Analysis

• Risk is the combination of the likelihood and severity of a

specified hazardous event occurring.

• In Mathematical term, risk can be calculated by equation :

RISK = Likelihood × Severity

Risk analysis method :

• Step 1 : Gather information about each hazard identified.

• Step 2 : Use the information to assess the likelihood and

severity of each hazard.

• Step 3 : produce a qualitative risk table.


(4) Risk AnalysisEXAMPLE :

“Likelihood” “Severity”

Calculation : If likelihood of a hazard is estimated = 2, and if severity is

estimated =4. So, Risk = 2× 4 = 8

Produce the Risk Table :

Very likely

(Daily)

4

Likely (Weekly) 3

Unlikely

(Monthly)

2

Highly unlikely

(yearly)

1

Fatality (or permanent

disability)

4

Major Injuries (> 4 days MC) 3

Minor Injuries (< 4 days MC) 2

Negligible Injuries (First Aid

and Near Misses)

1

No. Hazard Hazard Likelihood Severity Risk

1 A 4 4 16

2 B 1 1 2

3.3 Hazard Prevention and Deterrence

Hazard control method : Example

1. Eliminate the source of

hazard

Change the equipment contribute to the noise,

purchase pre-cast items.

If not practical, then

2. Reduce the hazard at source

/Substitute a less hazardous

equivalent

Use non hazardous chemical, change petrol type

forklift to electric type forklift, use vacuum cleaner

instead of broom.


3. Isolate the hazard Enclose them in barriers.


4. Use engineering control Use robot or other automated system


5. Apply appropriate

management strategies

Provide employee training, enforce safety workplace


6. Use appropriate PPE Wear safety helmet, gloves, goggles

3.4 Safety Management Concerns

When working in a safety management position, below are the

principal concerns:

1) Strategic Planning

2) Safety policy

3) Written procedures

4) Employee training

5) Communication

6) Human resource management

7) Self Assessments

8) Safety and health promotion

9) Accident Investigation and Reporting

10)Ongoing Monitoring

Summary : (HIRARC)

Hazard

Identification

Risk/ Hazard

Assessment

Risk/ Hazard

Control

Physical,

chemical,

biological….etc.

Preliminary/

detailed hazard

analysis.

Hazard

prevention, safety

management

concern

lecture 4-_hazard_analysis_prevention_and_safety_management

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