Accident case study

1. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 1 OF 8
5 WORKERS DIE
IN YEAST BREW VAT
ACCIDENT CASE STUDY

2. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 2 OF 8
ACCIDENT CAUSATION
 Domino Theory.
 Multiple Causation Theory.

3. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 3 OF 8
You are a member of the safety committee and have been notified
to report to work 3 hours early to assist in an investigation of an
accident. 2 maintenance workers and 3 bakers were found huddled
together at the base of an “Evenrise” yeast vat. All 5 five had
extreme “blueing” of the lips and fingernails. 1 other worker has
been taken to the hospital complaining of extreme headaches,
dizziness, disorientation and nausea. You and your group must
conduct an accident investigation to determine the root cause. The
bakery has been shut down and is losing $288,000 per day in
revenue.
5 WORKERS DIE IN YEAST BREW VAT
OVERVIEW OF THE INCIDENT
ACCIDENT CASE STUDY

4. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 4 OF 8
 Oval interior (10ft deep, 7ft wide, 6 feet wide)
 Interior access is achieved with a fixed metal ladder
 Rotating mixing arm at bottom of vat
 A 36” wide service door built into the top of the vessel
 12” wide flush portal for cleaning residual product
THE VAT
6ft
7ft
ACCIDENT CASE STUDY
10ft Deep
TOP VIEW
FLUSH PORT

5. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 5 OF 8
SIDE VIEW
EVENRISE
YEAST BREW VAT
ACCIDENT CASE STUDY
10ft Deep
FLUSH PORT

6. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 6 OF 8
ACCIDENT CASE STUDY
TOP VIEW
VICTIMS
SERVICE LADDERS
X
X
X
X
X FLUSH PORT

7. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 7 OF 8
ACCIDENT CASE CHRONOLOGY
12:02am: Baker 1 attempts to flush (clean) residual product from vat
12:10am: Baker 1 attempts to flush the vat, vat fails to flush
12:17am: Baker 1 attempts to flush vat for the third time
12:33am: Baker 1 reports the problem to maintenance
12:35am: Baker 1 tries to find supervisor, unable to locate
12:40am: Maint 1 arrives, enters vat through service door
12:44am: Maint 2 arrives and checks service box on rear of vat
12:49am: Maint 2 enters vat through service door
12:55am: Baker 1 hears noises, climbs ladder, looks into vat
12:55am: Baker 1 yells for help, enters vat through service door
12:55am: Baker 2 responds and enters vat through service door
1:25am: Supervisor arrives and enters through service door
2:55am: Baker 3 arrives, and enters vat
2:56am: Baker 3 is disoriented, immediately exits and notifies 911
3:17am: Responders find all 5 workers dead at the scene

8. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 8 OF 8
 What caused the deaths of these workers?
 Do you believe there is a single cause to this accident that,
if removed would have prevented it?
 Do you believe there are multiple causes?
 Are multiple OSHA Standard violations involved?
 What could upper management have done?
 What could the supervisor have done?
 What could the co-workers have done?
 To what extent is a lack of written policy responsible?
 What written policies need to be developed
 To what extent is a lack of training responsible?
 Were the hazards associated with yeast fully understood?
QUESTIONS TO BE CONSIDERED

9. COPYRIGHT 1995©
, SAFETY SERVICES®
ACCIDENT - SLIDE 9 OF 8
ACCIDENT CASE FACTS
 Hazard Communication program non-existent or ineffective
 Confined space program non-existent or ineffective
 Lock-Out Tag-Out program non-existent or ineffective
 Fall Protection program non-existent or ineffective
 Maintenance department allowed “lone-wolf” situation
 Bakery department allowed “lone-wolf” situation
 Written procedures did not address “lone-wolf” situation
 Supervisor did not have established “rounds” in department
 Hazards associated with yeast not fully understood