Fire assessment of a lab

Fire assessment of a lab

Qualitative Risk
Assessments
FIRE 4460
Fire Hazard and Risk Assessment
Nelson C. Dunston
Qualitative Fire Risk Assessments

Fire Risk based on subjective judgment of the
probability of a fire hazard or fire scenario, but
also the consequence of such a fire hazard or
fire scenario.

Risks are relative measures of risk based on
ranking or separation into descriptive
categories. (low, medium, high; not important,
important, very important; on a scale from 1
to 10.
Methods of Qualitative RA

Checklist Method

Risk Matrix Method

HAZOP Method

Event Tree Method
Checklists

Help identify fire hazards in unstructured,
qualitative risk assessments

Advantages: Tells the non

professional what
may constitute a fire hazard. Reminds
professional risk assessor of the range of fire
hazard

Disadvantages: Because it is a list, hazards can
be list and may not be all

inclusive.
Combustible Materia
ls

Products based on
flammable liquids

Flammable chemicals

Wood

Paper and card stock

Plastics, rubber, foam

Flammable gases

Textiles

Packaging materials

Waste materials (wood
shavings, offcuts, dust,
paper, textiles)
Ignition Sou
rces

Matches and smoking materials

Electric, gas or oil fired heaters

Hot processes such as welding and
grinding

Cooking

Engines and boilers

Machinery

Faulty or misused electrical
equipment

Lighting equipment (halogen lamps)

Hot surfaces and obstruction of
equipment ventilation

Friction from loose bearings or belts

Static electricity

Metal impacts such as metal tools
striking each other

arson
Sample List of Combustible Materials and Ignition Sources

Not all inclusive
Factors to determine the level of
hazard
from combustible material

Ignitability

some flammable liquids are easier to ignite
than others; thin items are easier to ignite than thick items.

Reaction to fire

rate of flame spread, HRR, smoke
production, toxicity

Amount

the higher the fuel load the greater the potential
rate of HRR and fire severity

Orientation

vertical, corner and ceiling surfaces and high

racked storage tend to increase the rate of flame spread

Location

materials that are grouped together or near exits
or large numbers of people may present an increased risk.