ERT 312ERT 312LECTURE 2

Accident & Loss Statistics Accident & Loss Statistics

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:3 ALS Systems:OSHA Incidence RateFatal Accident Rate (FAR)Fatality Rate, or Death per

Person per Year

OSHA Incidence RateOSHA Incidence RateBased on cases/100 worker yearsA 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

Number of lost workdays

Injury and illness (Equation 1)

Lost workdays (Equation 2)

Question 1.9 Question 1.9 (Crowl & Louvar, 2002)(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:Answers:OSHA IR (Injury and Illness) =

3.17OSHA IR (Lost workdays) = 22.83

FARFARBritish chemical industryBased on 1000 employees

working their entire lifetimeTotal working years/employee =

50 yearsTherefore, FAR is based on 108

working hours

Equation 3

Question 1.3 Question 1.3 (Crowl & Louvar, 2002)(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:Answer:Refer to table 1.4, FAR travelling

by car is 57 deaths/108 hours.Speed = 50 km/hA death will occur every 108/57 =

1.75 x 106 hours.Therefore, distance before a

death occur = 87.5 x 106 miles

Fatality RateFatality RateIndependent of the number of

hours actually workedBased on the general populationFAR Fatality rate

Question 1.5 Question 1.5 (Crowl & Louvar, 2002)(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:Answer:Expected industrial related death

per year = 0.15

NATURE OF ACCIDENT PROCESS & SEQUENCE

Table 1: Common Chemical Table 1: Common Chemical Plant Accidents Plant Accidents (Crowl & Louvar, 2002)(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 LossesCauses of LossesMechanical failureOperator errorProcess upsetsNatural hazardsDesign FlawSabotage/ArsonUnknown ???

Accident 3-Step SequenceAccident 3-Step Sequence

InitiationPropagationTermination

InitiationInitiationThe event that starts the

accident

Example: Mr. A threw away a burned cigarette bud into dried bushes

PropagationPropagationThe 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

TerminationTerminationThe 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)