Transcript EKC 367 - UniMAP Portal

ERT 312
LECTURE 2
Accident & Loss Statistics
Accident & Loss Statistics
A
measure
of
the
effectiveness of the safety
programs
 An
indicator
whether
a
process is safe or SOP is
working correctly
 Taken by average, thus not
reflect
for
single
events
involving substantial losses

3 ALS Systems:
OSHA Incidence Rate
 Fatal Accident Rate (FAR)
 Fatality Rate, or Death per
Person per Year

OSHA Incidence Rate
Based on cases/100 worker years
 A standard worker year = 2000 hours
◦ 50 weeks/year x 40 hours/week
 Therefore, OSHA IR is based on 200,000
hours of worker exposure to a hazard
◦ 100 worker years x 2000 hours

Injury and illness (Equation 1)
Lost workdays (Equation 2)
Number of lost workdays
Question 1.9
(Crowl & Louvar, 2002)
A university has 1200 full-time
employees. In a particular year
this
university
had
38
reportable lost-time injuries
and
274
lost
workdays.
Compute the OSHA IR based
on injuries and lost workdays.
Assume an employee works for
8hr, 250 days/year
Answers:
OSHA IR (Injury and Illness) = 3.17
 OSHA IR (Lost workdays) = 22.83

FAR
British chemical industry
 Based on 1000 employees working their
entire lifetime
 Total working years/employee = 50 years
 Therefore, FAR is based on 108 working
hours

Equation 3
Question 1.3
(Crowl & Louvar, 2002)

Assuming that a car travels at an average
speed of 50 km/h, how many kilometres
must be driven before a fatality is
expected?

Assume FAR for travelling by car=57
deaths/108
Answer:
Refer to table 1.4, FAR travelling by car is
57 deaths/108 hours.
 Speed = 50 km/h
 A death will occur every 108/57 = 1.75 x
106 hours.
 Therefore, distance before a death occur
= 87.5 x 106 miles

Fatality Rate
Independent of the number of hours
actually worked
 Based on the general population
 FAR
Fatality rate

Question 1.5

(Crowl & Louvar, 2002)
A plant employs 1500 full-time workers in
a process with a FAR of 5. How many
industrial related deaths are expected per
year?
Answer:

Expected industrial
death per year = 0.15
related
NATURE OF ACCIDENT
PROCESS & SEQUENCE
Table 1: Common Chemical
Plant Accidents (Crowl & Louvar, 2002)
Type of
Accident
Probability of
Occurrence
Potential for
Fatalities
Potential for
Economic Loss
Fire
High
Low
Intermediate
Explosion
Intermediate
Intermediate
High
Toxic Release
Low
High
Low
Causes of Losses
Mechanical failure
 Operator error
 Process upsets
 Natural hazards
 Design Flaw
 Sabotage/Arson
 Unknown ???

Accident 3-Step Sequence
 Initiation
 Propagation
 Termination
Initiation


The event
accident
that
starts
the
Example:
Mr. A threw away a burned
cigarette
bud
into
dried
bushes
Propagation


The
event
or
events
that
maintain or expand the accident
Example:
A portion of dried bushes
ignited, releasing thick smoke
and hot flame. Fire starts to
progress to another part of
bushes
Termination


The event or events that stop
the accident or diminish it in
size.
Example:
Consumption of combustible
materials in process, fire
extinguisher.
More example: refer to Table 1.7, Page 19 (Crowl & Louvar, 2002)