Fundamental Concepts

1
Fundamental Concepts Terms in Safety

• TM 650
• Safety Management
• Summer 2009
• Dr. Carter J. Kerk

2
Reading Assignment

• Asfahl
• Chapter 3
• Chapter 4

3
Why should a company address safety?

• Regulatory Reasons?
• Humanitarian Reasons?
• Economic Reasons?

4
What is an Accident?

• An event that is not expected or intended
• Could cause
• injury
• loss
• Implies chance

5
Types of Losses

• Injury
• illness
• disease
• death
• damage to property, equipment, materials
• cost of replacement
• legal medical services

• Loss of time, production, sales
• time to complete forms
• recordkeeping
• investigations
• cleanup
• hospitalization, rehab
• public image damage

6
Losses Direct vs. Indirect Costs

• Direct (Obvious)
• medical expenses, WC, repair or replace damages
• Indirect (Not Obvious)
• 41 Ratio (Iceberg Theory)
• Injured workers wages, lost supervisory time,
  co-workers lost time during emergency, damaged
  equipment, ruined product, overtime for
  production to catch back up, learning curve for
  replacement worker, clerical costs, payments made
  to injured under benefits program

7
Fundamental Accident Causes

• Unsafe Acts
• Unsafe Conditions
• Both
• Not necessarily a chance event

8
Unsafe Acts vs. Unsafe Conditions

• Heinrich analyzed 75,000 accidents
• 88 10 2 ratio
• 88 unsafe acts
• 10 unsafe conditions
• 2 unpreventable causes
• Engineers can attack unsafe conditions
• Must understand human behavior and management
  principles to attack unsafe acts

9
Accident - Injury Relationship

• Heinrichs 300 29 1 ratio
• For 330 accidents
• 300 result in no injury
• 29 produce minor injuries
• 1 produces major, lost-time injury
• Opportunities to improve are great
• Many accidents are rehearsed many times

10
Validity of Heinrichs Data

• Heinrichs concepts are classic, but the validity
  of his data has been called into question in
  recent years
• Apparently the data upon which Heinrich published
  his work is not available and has not been
  replicated successfully in other studies
• Regardless, his concepts provide excellent points
  for our thoughts

11
Accident - Costs Relationship

• Pareto Analysis or Relationship
• 80 - 20 rule
• 80 of the costs are related to 20 of the
  injuries
• for example, low back lifting injuries represent
  20 of all accidents, but represent 80 of the
  costs
• if you can manage and control that 20 of
  accidents, you can control 80 of the costs
• Next slide shows 50 of the costs are related to
  2 of the injuries - the powerful few
• And 67 of the injuries represent 6 of the total
  cost you could spend a lot of time on these
  and save very few

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Pareto Analysis The Vital Few
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Terms

• Safety being relatively free from harm, danger,
  damage, injury
• Risk measure of both frequency and severity of
  hazards
• Hazard unsafe condition, the potential for an
  activity or condition to produce harm

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Accident Theories

• Domino Theory
• Energy Theory
• Single Factor Theories
• Multiple Factor Theories

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Domino Theory (Heinrich)

1. Injury is caused by
2. Accidents which are caused by
3. Unsafe acts or conditions which are caused by
4. Undesirable traits (e.g., recklessness,
   nervousness, temper, lack of knowledge, unsafe
   practices) which are caused by
5. Social environment

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Domino Theory Cont.

• Stop the sequence by removing or controlling
  contributing factors
• Strong emphasis is placed on the middle domino
  unsafe acts or conditions

17
Energy Theory (Haddon)

• Accidents Injuries involve the transfer of
  energy, e.g., fires, vehicle accidents,
  projectiles, etc.
• Transfer of energy from a potential to
  kinetic
• Attack problems in parallel rather than serial
  (as is presumed in Domino Theory)

18
Energy Theory Cont.10 Strategies to Prevent or
Reduce

• 1. Prevent the marshalling of energy
• - dont produce the energy
• - dont let kids climb above floor level
• - dont produce gun powder
• 2. Reduce the amount of energy marshalled
• - keep vehicle speeds down
• - reduce chemical concentrations
• - dont let kids climb above 3

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3. Prevent the release of energy - elevator
brakes 4. Modify the rate at which energy is
released from its source or modify the spatial
distribution of the released energy - reduce the
slope on roadways 5. Separate in space or time
the energy being released from the structure that
can be damaged or the human who can be injured -
separate pedestrians from vehicles
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6. Separate the energy being released from a
structure or person that can suffer loss by
interposing a barrier - safety glasses, highway
median barriers 7. Modify the surfaces of
structures that come into contact with people or
other structure - rounded corners, larger
surface areas for tool handles 8. Strengthen the
structure or person susceptible to damage -fire
or earthquake resistant structures, training,
vaccinations
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9. Detect damage quickly and counter its
continuation or extension - sprinklers that
detect heat - tire tread wear bands 10. During
the period following damage and return to normal
conditions, take measures to restore a stable
condition - rehab an injured worker - repair a
damaged vehicle
22
Single Factor Theories

• Assumes that when one finds a cause, there is
  nothing more to find out
• Weak theory, there can be so much more to learn!

23
Multiple Factor Theories

• Accidents are caused by many factors working
  together
• The theory and the analysis is more complex, but
  more realistic than Single Factor Theory
• Consider the Four Ms
• management, man, media, machine
• And their interactions

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Concepts of Hazard Avoidance

• Approaches
• Enforcement
• Psychological
• Engineering
• Analytical
• To be successful you must have top management
  support!

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1. Enforcement Approach

• Your approach to hazard avoidance is entirely
  predicated upon avoiding regulatory fines.
• Many companies establish their safety programs to
  meet OSHA requirements thinking that is adequate.
• This is a bare minimum approach. While it may
  seem cost effective, it likely is not in the big
  picture.

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2. Psychological Approach

• Your approach to hazard avoidance is based on a
  psychological (or behavior-based) approach.
• The behavioral approach has been popular and
  widely used.
• DuPont STOPTM (Safety Training Observation
  Program)
• http//www2.dupont.com/Safety_Products/en_US/produ
  cts/programs_training/index.html
• To be successful, this approach needs to be ever
  vigilant, and must be infused with some
  engineering and analytical components

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3. Engineering Approach

• The engineering approach to hazard avoidance
  utilizes controls measures starting with
  engineering (then administrative, then PPE)
• Consideration of (see next slides)
• Safety Factor Concept
• Fail-Safe Concept
• Design Principles Design for Safety
• Be careful to avoid a false-sense of security
  from engineering and technology
• read Case Study 3.7
• Casey books

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Recommendation for Reading

• Set Phasers on Stun And Other True Tales of
  Design, Technology, and Human Error. Steven
  Casey. Aegean Publishing Company, Santa Barbara,
  CA. 1993. ISBN 0-9636178-7-7
• The Atomic Chef And Other True Tales of Design,
  Technology, and Human Error. Steven Casey.
  Aegean Publishing Company, Santa Barbara, CA.
  2006. ISBN 0-9636178-6-9

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Safety Factor Concept

• Since there is a chance element in safety, we can
  improve our chances by implementing a safety
  factor
• Scaffolding 41
• Designed to withstand 4 times the intended load
• Overhead crane hoists 51
• Scaffold ropes 61
• Why not use 101 as a standard??
• Beware when using field tables or computer
  programs. Are the safety factors applied or not??

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Fail-Safe Concept

• General fail-safe principle
• The resulting status of a system, in event of
  failure of one of its components, shall be in a
  safe mode.
• Read Case Studies 3.5 and 3.6
• Fail-safe principle of redundancy
• A critically important function of a system,
  subsystem, or components can be preserved by
  alternative parallel or standby units.
• Principle of worst case
• The design of a system should consider the worst
  situation to which it may be subjected in use.
• Murphys Law If anything can go wrong, it will.

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Engineering Design Principles

• Eliminate
• Substitute
• Guard
• Barriers
• Warn with alarms (auditory, visual)
• Labels

• Filters
• Exhaust ventilation
• Human Interface

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4. Analytical Approach

• The analytical approach to hazard avoidance
  utilizes various qualitative and quantitative
  tools
• Accident Analysis
• System Safety Techniques (see next slide)
• Loss Incident Causation Models
• Proximal and Distal Causes (McClay)
• Toxicology
• Epidemiology
• Cost-Benefit Analysis

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System Safety Techniques

• Preliminary Hazard Analysis
• Hazard Tracking Log
• Subsystem Hazard Analysis
• System Hazard Analysis
• Operating Hazard Analysis
• Change Analysis
• Accident Analysis
• Time-Loss Analysis
• Event and Causal Factor Charts
• Process Safety Management

• Fault Tree Analysis (FTA)
• Energy Trace Barrier Analysis (ETBA)
• Failure Mode Effects Analysis (FMEA)
• Project Evaluation Tree (PET)
• Management Oversight Risk Tree (MORT)
• Software Hazard Analysis
• Common Cause Failure Analysis
• Sneak Circuit Analysis

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How Safe is Safe Enough?

• Can absolute safety be achieved?
• Remember the concept of risk.
• What is acceptably safe?
• Remember the Risk Assessment Matrix Severity
  versus Frequency

35
References

• In addition to Asfahl
• Brauer RL. Safety and Health for Engineers, 2nd
  edition, Wiley, 2006.
• Manuele FA. On the Practice of Safety, 3rd
  edition, Wiley, 2003.
• Stephans RA. System Safety for the 21st Century,
  Wiley, 2004

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HW6 Chapter 3

• Exercises Study Questions, p. 77-80
• 1-41, divisible by 3
• Research Exercises, p. 80
• 42-45, pick one
• Standards Research Questions
• 46-48, pick one
• due asap

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HW7 Chapter 4

• Exercises Study Questions, p. 101-102
• 1-29, divisible by 3
• Research Exercises, p. 102-103
• 30-40, pick two
• Standards Research Questions
• 41-43, pick one
• due asap

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HW8 Hazard Awareness Advisor

• Go to www.osha.gov
• Search on e-tools
• Go to Expert Advisors
• Select Hazard Awareness and download it to your
  computer or run it online
• Run this expert system to evaluate your
  workplace or someplace you have worked.
• Write a one page memo that describes what you
  have learned from this exercise. I especially
  want to know if youve learned of some new
  workplace hazards. Do you think this is a useful
  tool for industry?
• due asap