ERGONOMICS
Know Your Limit. Work Within It!
Presented to:
Canadian Manufacturers & Exporters
Employers’ Advocacy Council
Health and Safety Symposium
“Creating a Culture of Workplace Excellence”
March 23rd, 2016
Presented by:
Kevin Schouppe, B.Sc. (Kin.)
Principal/Ergonomics Consultant
OSHTECH Ergonomics Group Inc.
Associate Faculty Member, Conestoga College
Fundamentals of Ergonomics
[email protected]
www.oshtechinc.com
Ergonomics. Know Your Limit. Work Within It!
Introduction & Session Description: Today’s
society places a great emphasis on limits.
Reminders of speed limits, drinking limits and
gambling limits are everywhere. At work, we
have limit switches, chemical limits, noise
exposure limits, and many more. But what
about ergonomics limits? Awareness and
understanding is weak. Perhaps this is why
musculoskeletal disorders (MSD’s) comprise
more than 40% of the WSIB statistics? This
session will introduce you to a variety of
ergonomics exposure limits that could enrich
your occupational health, safety and MSD
prevention programs. (CME/EAC, H&S Symposium, March 23 , 2016)
rd
A little background information...
“Creating a Culture of
Workplace Excellence”>
Noise Exposure> Know Your Limits
Noise “exposure limits”:
(3) Every employer shall take all measures reasonably necessary
in the circumstances to protect workers from exposure to
hazardous sound levels. (In Reg. 381 is Sec. 2(1))
(6) Without limiting the generality of subsections (3) and (4), every
employer shall ensure that no worker is exposed to a sound level
greater than an equivalent sound exposure level of 85 dB(A), Lex,8.
(In Reg. 381 is Sec. 2(4))
Example Order/Requirement:
How do I know if I am overexposed relative to the limit of Lex,8 of 85 dB(A)?
"Equivalent"
Noise
Time
(decibels)
(hours)
85
88
91
94
97
100
8
4
2
1
0.5
0.25
Noise Exposure Limit> Work Within It!
Shipper Dosimeter
(Dosimeter 153, Mth Day Year)
Leq = 87.67 dB(A)
120
Lex,8 = 87.94 dB(A)
MOL
Criteria
85 dB(A)
110
100
Noise Level (dB(A))
90
80
70
60
NIOSH
Reco mmended
PPE Limit
80 dB(A)
50
40
30
20
10
0
7:54
AM
8:24
AM
8:54
AM
9:24
AM
9:54
AM
10:24 10:54 11:24 11:54 12:24 12:54
AM
AM
AM
AM
PM
PM
1:24
PM
1:54
PM
2:24
PM
Time of Shift
Concept> “employee exposure evaluation” versus “exposure limit”?
If overexposed> health and safety controls are necessary!
Ergonomics> Know Your Limits
How many “ergonomics limits” in our health & safety laws?
Hint> Think occupational hygiene> TWA? STEL? CEL?
Physical Demand or Ergonomics Risk Factor?
Are they the same?
Physical Demands
sit, stand, walk
stoop, bend, twist, lean
squat, crouch
climb, kneel, crawl, balance
lift, lower, push, pull, carry
grip, handle
pinch, finger,
reach
throw
Ergonomics Risk Factors
Awkward postures
Forceful exertions
Repetitive/prolonged motions
Contact stresses
Vibration
Temperature extremes
Key concepts:
Physical demands and ergonomics risk factors are different.
Manage these differences appropriately in WSIB, OH&S and ergonomics/MSD Prevention Programs.
“I Spy with my Ergonomics Eye”
Practice your hazard recognition skills>
Physical Demand or Ergonomics Risk Factor?
Bending
Awkward
whole-body
posture
Reaching
Forceful wholebody Exertion
Squatting
Gripping
Standing
Cold
Temperature
Whole-body
Contact stress
PDP’s & Ergonomics Survey Tools> Know Your Limits
What is a “PDA”, “PDD”, “PDIF”?
i. Physical Demands “Analysis” (PDA) e.g. MOL, WSPS
ii. Physical Demands “Description” (PDD) e.g. OHCOW
iii. Physical Demands “Information Form” (PDIF) e.g. WSIB
iv. Physical Demands “Profile” (PDP)
Do PDP’s present limits?
Ergonomics Survey Tools:& “exposure limits”:
Workstation design guidelines
Snook maximum weights/forces
Biomechanical models
NIOSH Work Practices Guide & Lifting Equation
ACGIH® AL & TLV® for heat stress, lifting, hand activity level
Rapid Upper Limb Assessment (RULA)
And many more>
“Analysis”>degree of injury potential or risk.
Requires exposure evaluation relative to known injury mechanisms or exposure limits!
Ergonomics. Know Your Limit. Work Within It!
Example: Concerns about MSD’s due to awkward postures &/or extended reaches?
Analysis using workstation design guidelines for work heights & reach distances.
Ergonomics design guidelines based on body size & shape i.e. anthropometrics.
Ergonomics. Know Your Limit. Work Within It!
Example: Concerns about cardiovascular health due to physical demands?
Figure 1: Heart Rate (Monitor #1)
Heart Rate (HR)
180
170
Break avg
HR = 90
bpm
Break avg
HR = 93
bpm
15-min. avg. HR
160
150
Heart Rate (bpm)
140
130
120
110
100
90
80
70
60
4:05 PM 4:35 PM 5:05 PM 5:35 PM 6:05 PM 6:35 PM 7:05 PM 7:35 PM 8:05 PM 8:35 PM 9:05 PM 9:35 PM 10:05 PM 10:35 PM
Time of day
Analysis using ergonomics guidelines regarding working heart rates.
Ergonomics guidelines indicate acceptable average pulse for 8-hour workday is 90-110 beats per minute.
Ergonomics. Know Your Limit. Work Within It!
Example: Concerns about physical demands & general fatigue potential?
Analysis using limits for metabolic rates & energy expenditure!
NIOSH Energy Expenditure Design Limit: A job metabolic rate of an average of 3.5 kcal/min over an 8hour shift is believed to be acceptable to 99% males & 75% females. i.e. nominal fatigue potential.
Ergonomics. Know Your Limit. Work Within It!
Example: Concerns about energy expenditure in hot environments?
Analysis using metabolic rates & workload ratings & workplace temperatures!
ACGIH® Heat Stress “Workload Categories”:
Rest <115 Watts
Light 115 – 180 Watts
Moderate 180 – 300 Watts
Heavy 300-415 Watts
ACGIH® Heat Stress Limits “WBGT”:
Action
Threshold
Limit
Limit Value®
Light at 180 Watts
28 oC
31 oC
Moderate at 300 Watts
25 oC
28 oC
Ergonomics. Know Your Limit. Work Within It!
Example: Concerns about upper extremity MSD’s due to overuse & repetition?
Analysis based on forearm/hand movement frequency, pauses and forces.
ACGIH® Hand Activity Levels (HAL): Action Limits (AL) & Threshold Limit Values (TLVs ®).
Ergonomics. Know Your Limit. Work Within It!
Example: Concerns about back injury due to cumulative manual materials handling?
Liberty Mutual MMH Guidelines a.k.a. “Snook Tables”
Maximum acceptable weights for lift, lower & carry.
Maximum acceptable forces for push & pull.
Gender-specific limits for 75% of males & 75% females
Back injury risk is 3-fold if actual task demands > limits.
NIOSH Work Practices Guide & Lifting Equation
Recommend Weight Limits (RWL) for lifting.
RWL for 99% of males & 75% females.
Lifting Index (LI): nominal, increased or “nearly all” at risk.
Analysis using maximum acceptable weights & forces;
and recommend weight limits & lifting index.
.
Ergonomics. Know Your Limit. Work Within It!
Example: Concerns about overexertion of the back &/or other joints e.g. shoulder?
Analysis using biomechanics models of anthropometrics, MMH techniques & task weights/forces.
Example U of M 3DSSPP:
•
•
Back Compression Design Limit (BCDL) = 3400 Newtons (N)
Back Compression Upper Limit (BCUL) = 6400 Newtons (N)
Joint (e.g. shoulder) Strength Design Limit (SDL) = 99% of males and 75% of females capable
Joint (e.g. shoulder) Strength Upper Limit (SUL) = < 25% of males and 1% of females capable
Ergonomics Survey Tools: More Info About these Limits?
Have you reached your limit on ergonomics limits?
MSD Prevention Guideline of Ontario
Part 1:
Musculoskeletal Disorder Prevention Guideline
Part 2:
Resource Manual for the Musculoskeletal Disorder Prevention Guideline
Part 3:
Musculoskeletal Disorder Prevention “Toolbox”
3A:
Getting Started
3B:
Beyond the Basics
3C:
In-depth Risk Assessment Methods
Ergonomics. Know Your Limit. Work Within It!
Q&A>
Thank you:
Introduction & Session Description: Today’s
society places a great emphasis on limits.
Reminders of speed limits, drinking limits and
gambling limits are everywhere. At work, we
have limit switches, chemical limits, noise
exposure limits, and many more. But what
about ergonomics limits? Awareness and
understanding is weak. Perhaps this is why
musculoskeletal disorders (MSD’s) comprise
more than 40% of the WSIB statistics? This
session will introduce you to a variety of
ergonomics exposure limits that could enrich
your occupational health, safety and MSD
prevention programs. (CME/EAC, H&S Symposium, March 23 , 2016)
rd
On behalf of:
Kevin Schouppe, B.Sc. (Kin.)
Principal/Ergonomics Consultant
OSHTECH Ergonomics Group Inc.
Associate Faculty Member, Conestoga College
Fundamentals of Ergonomics
[email protected]
Tel: (519) 883-4727
www.oshtechinc.com