OCCUPATIONAL SAFETY AND HEALTH

(KAS3501)

YEAR 3 ; 6th SEM

GROUP 6

Presentation Date: 1 April 2015MATRIC NO. NAME

UK29558 PHON MUN YEEUK29505 ADIBAH BT AYOBUK29506 NOOR AIN NAJIHAH BT AZHAR

UK29507 NASRULLAH AMRI B. BAHAR

UK29511 SITI KHADIJAH BT ARIFFIN

DOW FIRE AND EXPLOSION INDEX (DOW

F&EI) & MOND INDEX

DOW FIRE AND EXPLOSION INDEX

(DOW F&EI)

WHAT IS DOW FIRE AND EXPLOSION INDEX?

• The hazard classification guide developed by Dow Chemical Company.

• Published by the American Institute of Chemical Engineering, Dow (1994).

• It gives a method of evaluating the potential risk from process, and assessing the potential loss.

OBJECTIVES OF DOW F&EI

• Quantify:• The expected damage of potential fire &

explosion incidents in realistic terms

• Identify:• Equipment that would likely contribute to

the creation or escalation of an incident

• Communicate:• The fire & explosion potential to design

teams and plant personnel

• It is tailored for storage, handling and processing of explosive and flammable material in chemical process industry.

• It uses systematic approach based on rating form.

• Suitable to be used at an early stage of a project and for auditing existing plant.

• Final rating number (i.e F&EI) provided a relative ranking of hazard.

• It is also used for estimating damage radius (using Dow correlation) and estimate dollar losses in the event of accident (using consequences analysis form).

WHEN SHOULD ONE PERFORM AN FEI?

• Late in Phase III Engineering after:

• P&IDs have been completed,

• Equipment has been sized,

• A trial equipment layout has been done,

• A DFC estimate has been completed.

WHO USUALLY PERFORMS THE FEI?

• Generally a senior process engineer, who is acquainted with the details of the project, is assigned the task.

• Occasionally, different groups tackle the assignment and results are compared for consensus building.

GENERAL PROCESS HAZARD• The general process hazards are factors

that play in primary role in determining the magnitude of the loss following an incident.

1. Exothermic chemical reaction

2. Endothermic processes

3. Materials handling and transfer

4. Access of emergency equipment

5. Drainage and spill control

SPECIAL PROCESS HAZARDS• The special process hazards are factors

that are known from experience to contribute to the probability of an incident involving loss.

1. Toxic materials

2. Sub-atmospheric pressure

3. Operation in or near flammable range

4. Dust explosion

5. Leakage

PARAMETER IN F&E INDEX

• Material Factor (MF)

• Measure of Reactivity and Flammability

• General Process Hazards (F1)

• Play a primary role in determining the magnitude of a loss incident

• Special Process Hazards (F2)

• Contribute to the probability of a loss incident

• FIRE & EXPLOSION INDEKS (F&EI)

• A measure of the relative hazard and relates to an exposure radius

• LOSS CONTROL CREDITS (LCCF)

• Are features that have proved beneficial in preventing serious incidents and reducing the magnitude of a particular incident

* Process Control

* Material Isolation

* Fire Protection

• Actual Maximum Probable Property Damage (MPPD)

• Represents the property damage that could result from an incident of reasonable magnitude with adequate functioning of protective equipment

• Maximum Probable Days Outage (MPDO)

• Time required to rebuild the plant to its original capacity

• Business Interruption (BI)

• The lost profit to the company due to an incident

PROCEDURE FOR CALCULATING DOW F&EI

SIMPLIFIED PROCEDURE FOR CALCULATING DOW F&EI

FORM FOR DETERMINING DOW F&EI

DETERMINATION OF MATERIAL FACTOR

Table 10.1 is used to obtain the material factor, MF value for the related compound.Compound with higher MF means it has higher flammability and/or more explosive.For a mixture, select the compound with the highest MF value.

PENALTY FACTORS

Dow’s Fire & Explosion Index Hazard Classification Guide, 7th EditionAmerican Institute of Chemical Engineers (AIChE)ISBN: 0-8169-0623-8Publisher: Wiley

The value for penalty factors, F1 or F2 is given as suggested in this guide book.

*For no penalty use 0.0

DEGREE OF HAZARD FROM THE DOW FIRE AND EXPLOSION INDEX

Dow F&EI Degree of hazard1-6061-9697-127128-158159 and above

LightModerateIntermediateHeavySevere

Determination of Fire and Explosion Index,

F&EI

MFFF

MFFEIF

21

3

&

LOSS CONTROL CREDIT FACTOR, LCCF

LOSS CONTROL CREDIT FACTOR, LCCF

PROCESS UNIT RISK ANALYSIS

PROCESS UNIT RISK ANALYSIS

Parameter Reference Equation

Radius of exposure, R Figure 7 (F&EI, R)

Area of exposure, AOE -

Value of area of exposure ($5000/m2)

- -

Damage factor, DF Figure 8 (MF, DF,F3)

Base Maximum Probable Property Damage (Base MPPD)

-

Actual MPPD -

Maximum Probable Days Outage (MPDO)

Figure 9 (Actual MPPD, MPDO)

Business Interruption, BI -

(VPM=Value of production for the month)

2RAOE

AOEDFMPPD Base

LCCFMPPD BaseMPPD Actual

0.7VPM30

MPDOBI

BASIC PREVENTATIVE AND PROTECTIVE MEASURES

The basic safety and fire protective measures that should be included in all chemical process designs are listed below:

1. Adequate, and secure, water supplies for fire fighting.

2. Correct structural design of vessels, piping, steel work.

3. Pressure-relief devices.

4. Corrosion-resistant materials, and/or adequate corrosion allowances.

5.Segregation of reactive materials

6. Earthing of electrical equipment.

7. Safe location of auxiliary electrical equipment, transformers, switch gear.

8. Provision of back-up utility supplies and services.

9. Compliance with national codes and standards.

10. Insulation of hot surfaces.

MOND INDEX

• It is an extension of the Dow index.

• Involves making an initial assessment of hazard similar to that used in the Dow index, but taking into account additional hazard considerations.

• The potential hazard expressed in terms of the initial value of a set of indices for fire, explosion and toxicity. These included:

• Fire load index

• Unit toxicity index

• Major toxicity incident index

• Explosion index

• Aerial explosion index

• Overall index

• Overall risk rating

PREVENTION MEASURES• Prevention measures fall into two categories:

1. Those that reduce the number of incidents.

- such as: sound mechanical design of equipment and piping; operating and maintenance procedures, and operator training.

2. Those that reduce the scale of potential incident.

-such as: measures for fire protection, and fixed fire fighting equipment.

• Many measures will not fit neatly into individual categories but will apply to both.

SUMMARY

• The Dow and Mond indexes are useful techniques, which can be used in the early stages of a project design to evaluate the hazards and risks of the proposed process.

• Calculation of the indexes for the various sections of the process will highlight any particularly hazardous section and indicate where a detailed study is needed to reduce the hazards.

REFFERENCES

• American Institute of Chemical Engineers . (1994). Dow's Fire & Explosion Index Hazard Classification Guide, 7th Edition.

• Gupta, J. P., Khemani, G., & Mannan, S. (2003). Calculation of Fire and Explosion Index (F&EI) value for the Dow Guide taking credit for the loss control measures. Journal of Loss Prevention in the Process Industries, 235-241.

• Tyler, B. J. ( 2004). Using the mond index to measure inherent hazards. Plant/Operations Progress, 172–175.