WSH ppt

WORKPLACE SAFETY
AND HEALTH 1
Ergonomics

GROUP MEMBERS

 Bak Fong Ning
 Eunice Chua
 Lam Man Pan Anna
 Tan Yu Jie
 Tong Ji Feng
 Xia Dong

SCOPE (PART 1)
What Reason for Flowchart on
Definition:What
Ergonomics using ergonomics
is Ergonomics?
does? Ergonomics? study

Background
Introduction of
What regulator Symptoms of information of
ergonomics
says? poor ergonomics ergonomics
hazards
hazards

Summary list of
Risk factors and
ergonomic
measurement
hazards

SCOPE (PART 2)
How to improve What you can do
Budgets for the How to pick your
work to improve Indoor
control items perfect chair?
ergonomically? Air Quality?

Designing How to adjust the
What are the
productive seating classroom and Does ergonomics
practical
in classroom and laboratory to fit work?
solutions?
laboratory you?

What is the References
design furniture Conclusion
for change?

WHAT IS ERGONOMICS?
 The branch of science that is concerned with the achievement of
optimal relationships between workers and their work
environment

Ergonomics

Worker Work environment

WHAT IS ERGONOMICS?
 Deals with the assessment of the human’s capabilities and
limitations
 Work and environmental stress
 Static and dynamic forces on the human body structure
 Vigilance
 Fatigue
 Design simulation and design of workstation and tools

WHAT IS ERGONOMICS?
 A multidisciplinary science which draw heavily from other fields of
study like:
 Mathematics
 Biological science
 Psychological science
 Physics

WHAT DOES ERGONOMICS DO?
 Goal: To adapt work to individuals rather than individuals to work
 By developing knowledge that results in efficient adaptation of
work methods to the individual physiological and psychological
characteristics

WHAT ARE THE REASONS FOR
ERGONOMICS?
 Achieve an optimal relationship between people and their work
environment.
 Reducing occupational injury and illness reduction,
 Containing workers' compensation costs,
 Improving productivity of the workers,
 Improving work quality,
 Reducing absenteeism
 Complying with the government regulations.

HOW WE CONDUCT A ERGONOMIC
STUDY?

BACKGROUND INFORMATION OF
ERGONOMICS HAZARDS
 Occur when type of work, body position and working conditions put
strain on one’s body
 Hardest to spot because strains on a person’s body or harm from
these hazards not always immediately noticed
 Short-term exposure result in "sore muscles" the next day or in days
following exposure
 Long term exposure result in serious long-term injuries

INTRODUCTION OF ERGONOMIC
HAZARD
 Workplace conditions that pose risk of injury to the
musculoskeletal system of worker
 Includes repetitive and forceful movements, vibration, temperature
extremes, and awkward postures that arise from improper work
methods and improperly designed workstations, tools, and
equipment

 Examples of Ergonomic hazards :
 Poor lighting
 Improperly adjusted workstations and chairs
 Frequent lifting
 Poor posture
 Awkward movements, especially if they are repetitive
 Repeating the same movements over and over
 Having to use too much force, especially if you have to do it
frequently

SYMPTOMS OF POOR
ERGONOMICS
 Cumulative Trauma Disorders (CTDs) are a class of
musculoskeletal disorders involving damage to the nerves of the
hands, wrists, elbows, shoulders, neck, and back.
 The more frequently occurring occupationally induced disorders in
this class include carpal tunnel syndrome (CTS).
 CTDs are caused when workers are required to perform keyboard-
intensive tasks without breaks or alternative work.

WHAT REGULATOR SAYS?
 Occupational Safety and Health Administration (OSHA) of the federal
government lists ergonomics as a key factor in preventing
musculoskeletal injuries in the workspace.

 OSHA expresses concern over poor design of furniture that does fit
the task, and ineffective safety devices: anything that might
precipitate an injury.

 Stress through prolonged sitting can be resolved to a great extent
with an increased awareness of correct posture.

 Three basic sitting positions can promote a healthy posture: the torso
may be positioned slightly forward, upright, or slightly reclining and
always with both feet resting comfortably on the floor or on a footrest

ERGONOMIC ANALYTICAL TOOLS
 Provide job prioritization for intervention, quantification of activities
associated with increased risk of injury, or recommendation for a
load weight limit for lifting
 Used by examiner to determine which analytical tool is best for
evaluation of the identified risks based on the understanding of
the tool’s application, strengths and weaknesses

1. Rapid Upper Limb Assessment (RULA)
 Assesses the risk of cumulative trauma, disorder through posture,
force, and muscle-use analysis
2. Ovako Working Posture Analysis System (OWAS)
 Provides intervention, prioritization based on posture and loads
3. Repetitive Motion Evaluation
 Analyses posture, repetition, and discomfort to reveal the
performance of high risk motions

4. Observation Analysis of the Hand and Wrist
 Quantifies hand exertions associated with risk factors of pinch
grip, high force, wrist flexion/extension/ulnar deviation, power tool
exertion, and use of hand to strike object
5. Utah Back Compressive Force Model
 Evaluates the risk of low back injury for a one-time lifting task
based on lumbar disc compression
6. Utah Shoulder Moment Model
 Evaluates the risk of shoulder injury for a onetime lifting task
comparing task moment to an individual's capacity

7. NIOSH Work Practices Guide (1981)
 Evaluates the risk of a lifting task based on NIOSH parameters
8. Revised NIOSH Lifting Equation (1994)
 Evaluates the risk of a lifting task based on expanded NIOSH
parameters
9. Liberty Mutual Tables
 Based on psychophysical experimentation, determines the
maximum acceptable weight for a lifting/lowering task,
push/pulling task, and carrying task given selected job
characteristics. Tables are accessible from the Lifting/Manual
Material Handling Job Review and Analysis Options

10. Amsterdam Master's in Medical Anthropology (AAMA) Metabolic
Model
 Evaluates the risk of physical exertion strain for a task
11. Anthropometry Analysis
 Determines proper workplace dimensions for various body sizes
12. Detailed Checklist For Computer Video Display Terminals (VDT)
Workstation Risk Analysis
 Presents the recommended characteristics of a VDT workstation

POTENTIAL ERGONOMICS HAZARD
(BLK 34-06-02)
 Improper design of computer workstation
 Excessive overhead lighting
 Improper design of facilities (tables and chairs)
 Lifting and moving of tables or chairs
 Long period of time standing
 Long period of time sitting
 Continuous writing with hand or typing on a laptop/computer
 Tripping of electric cord
 Unclean air conditioner and ventilators

POSSIBLE CONTROL MEASURES
 Engineering control
 Administrative control

ENGINEERING CONTROL
 Use of foot rest
 Position the chair and desk such that the knee and forearms are
90° angles, with wrist straight and feet flat on the floor or foot rest
 Position the computer such that the top of the screen is at or just
below the eye level, and the viewing distance is a safe distance
away from the user eyes
 Excessive overhead lighting
 Use of adjustable tasks lights ambient lighting
 Use of anti-glare whiteboard

 Improper design of facilities
 Use of flexi-chair (changing seat inclination) or rocking
mechanisms (swivel chair with height adjustment)
 Use of height adjustable working table or inclined top
 Use of adjustable stool with a backrest
 Adjust the chair height such that the feet rest comfortably on the
floor or foot rest

 Use of anti-fatigue mat
 Continuous writing with hand
 Use of better grip pen
 Tripping of electric cords
 Use of cable protector or floor cord cover
 Unclean air conditioner and ventilators
 Install new unit ventilators and air handlers or regular cleaning
and maintenance of ventilation system

ADMINISTRATIVE CONTROL
 Lifting and moving of tables and chairs
 Request for help when lifting or moving heavy objects
 Long period of sitting and standing, and continuous writing with
hand
 Taking short breaks in between the work schedule

POTENTIAL ERGONOMICS HAZARD
(BLK 35 LABORATORY)
 Long period of time sitting
 Long period of time standing
 Repetitive pipetting
 Improper design of facilities (fume hoods, biosafety cabinet, laboratory
workbenches)
 Improper design of computer workstation
 Moving of heavy objects
 Stress
 Compact work surface
 Excessive overhead lightings
 Personal laboratory equipment

POSSIBLE CONTROL MEASURES
 Engineering control
 Administrative control
 Personal protection equipment (PPE)
 Work practice controls

ENGINEERING CONTROL
 Use of adjustable lab stool with backrest
 Adjust chair height such that the feet can rest comfortably on the
floor or footrest
 Tilt the chair seat forward to prevent leaning
 Keep frequently used items within arm reach
 Use of anti-fatigue mat
 Place one foot on a small stool and alternate to reduce pressure
to the back

 Repetitively pipetting
 Elevate chair according to working height
 Use of light-weight pipette or electronic or latch-mode pipette
 Use of multi-finger control
 Use thin-walled pipette tips
 Work the pipette with arm close to body to reduce strain on
shoulder

 Improper design of facilities (fume hoods, biosafety cabinets and laboratory
workbenches)
 Position materials in fume hood as close as possible to avoid extended
reaching
 Apply padding for arm and wrist to rest
 Lights in fume hood must be working properly. Replace bulbs when
necessary
 Use ergonomically designed chairs with proper back support, seat angle and
height adjustability
 Use foot rest
 Removal of drawers under workbenches
 Use turntable to store equipment to avoid extend reaching and twisting
 Proper design of stool or benches such that it is not too high for most users to
use

 Improper design of computer
workstation
 Provide fully adjustable seating
 Place monitor such that the
top of the screen is near or at eye
level to allow the eye to naturally
gravitate towards the center of the
screen
 Provide foot rest for user to
change leg position through the
day
 Regular maintenance of workstation, chairs and equipment
 Use of padded wrist rest
 Ensure that the user shoulder muscles or tendon does not work to reach
forward or out to side, otherwise, further alteration of workstation is
needed
 Ensure that the keyboard and input device (mouse) is at the same level
and in front of the computer, and the height of the keyboard and input
device should allow the user to position their forearms and hands parallel
to the floor
 Adjust monitor contrast and brightness for maximum personal comfort of
user

 Moving of heavy objects
 Use handling equipment (lifts or hoist) to avoid manual handling
 Push instead of pull
 Use sliding motion or lateral transfers instead of lifting the load
 Decrease the weight of load and allow more frequent trips of moving
lighter load
 Pivot the feet instead of twisting the back when lifting the load
 Compact work surface
 Ensure work surface is large enough to allow free leg movement
 Ensure the height of work surface allow the forearms to be parallel to
the floor when working, avoid having shoulder elevated
 Excessive overhead lightings
 Use a task tamp when needed

ADMINISTRATIVE CONTROL
 Long period of time sitting and standing, repetitively pipetting,
improper design of facilities (fume hood, biosafety cabinet and
laboratory workbench), improper design of computer workstation,
and moving of heavy objects
 Take short breaks in between the work schedule
 Moving of heavy objects
 Optimize work shift scheduling to minimize extended work load
 Ask for more people to assist moving load

PERSONAL PROTECTION EQUIPMENT
(PPE)
 Personal laboratory equipment
 Safety goggles
 Gloves

WORK PRACTICE CONTROL
 Repetitively pipetting
 Introduce worker education and awareness sessions
 Early reporting of signs and symptoms of ergonomic concerns
 Training for user on ergonomics hazard and control strategies

CONTROL ITEMS FOR
LABORATORY
 Deluxe goggles (S$15.12)

 Crag work boot (S$185.76)

 Edge protector – 0.762m
(S$23.24)

 Adjustable work benches – 0.762m x 1.524m (S$1249.58)

 Vinyl Cover seat with adjustable
height (adjustable from 0.508m
to 0.686m in height)
(S$577.19)

 Safety fatigue mat – 0.102m x 1.524m (S$738.08)

 Wireless ergonomic multimedia keyboard and mouse (S$64.68)

CONTROL ITEMS FOR
CLASSROOM
 Floor cord cover – 7.62m (S$49.75)

 Fully ergonomics design with
smooth nylon mesh back
and genuine leather seat
pan chair (S$150)

 Anti-glare whiteboard (S$11.00)

 Wireless ergonomic multimedia keyboard and mouse (S$64.68)

HOW TO IMPROVE WORK
ERGONOMICALLY
 Know the current working condition of the workplace
 Get compared with the legislation or COP
 Identify the potential factors which may cause injury to the
workers and list them out
 Give suggestions to make changes regarding the unsuitable
factors
 When all details of every area in the workplace is considered,
examined and actions have been done, work is improved
ergonomically
 Having proper chair-height adjustment can help keep the
wrists in a flat position, and the control of both backrest angle
and seat-pan forward-tilt further aids in relaxation and the
reduction of muscular tension while helping proper hand arm
orientation.

WHAT YOU CAN DO TO IMPROVE
INDOOR AIR QUALITY
1. Apply good ventilation system
2. Choose suitable ventilation system. (LEV system for workplace
with gaseous pollutants produced by fixed origins with high
concentration)
3. Monitor the air quality constantly.
4. Clean the duct or other ventilation system components regularly.

HOW TO PICK YOUR PERFECT CHAIR?

 Chair is the most important piece of furniture.
 Without a comfortable, supportive chair, you would not be an efficient worker.
 Sitting for prolonged periods of time can cause poor posture and reduce
circulation of the blood, which often results in severe back pain.
 An ergonomic chair should provide your back, especially your lumbar region
(lower back) with support.
 A quality chair should have an adjustable lumbar support
 Users should be able to move the back rest forward, reducing the seat pan
depth, to ensure that people with shorter legs receive proper back support
while still being able to rest their feet on the ground or foot rest.
 They should be able to adjust the back support forward or backward to
accommodate the curvatures of the spine and properly support their body
weight.

HOW TO PICK YOUR PERFECT CHAIR?

 Important that the seat height be adjustable.
 A footrest also can help improve comfort for a shorter user who is
working at a fixed-height work surface.
 A good ergonomic chair also allows adjustment of both the back-tilt
angle and seat pan depth while seated.
 Seat pan (the surface on which you actually sit) should have a soft
front edge, ensuring that there are no pressure points to hurt the
underside of the thighs.
 Perfect chair should allow users to sit upright with arms hanging
straight down from the shoulders and with the elbows bent
 Allow users to sit flat on the chair with knees bent and feet flat on the
floor or foot rest and it should support the user’s back in an upright
position.

HOW TO ADJUST THE CLASSROOM
AND LABORATORY TO FIT YOU?
a) Adjust your chair
 Arm position
1. Raise your forearms to be parallel with the floor while maintaining a
90 degrees elbow bend.
2. Adjust your chair to achieve this position. Keep the wrist straight as
an extension of your forearms.
 Foot support
1. Move your feet forward until your knees are at a 90 to 110 degrees
angle. Your feet should rest firmly on the floor with 3-6 inches
(7.62cm-15.24cm) of leg room between your lap and desk.
2. If you do not have a footrest and cannot adjust your chair height or
your feet don not touch the floor, use a phone book or a 3-ring binder
as a quick and easy footrest.

HOW TO ADJUST THE CLASSROOM
AND LABORATORY TO FIT YOU?
 Backrest
1. Sit in your chair with the backrest snugly against your lower back.
2. You should be able to place your hand easily between the back of
your knees and the edge of the seat pan.
3. If you cannot do this, you may be able to achieve improved
support by placing a pillow between your seat and lower back to
restore natural curvature.

Flow chart
on adjusting
the chair to
fit you

DESIGNING THE PRODUCTIVE
SEATING IN CLASSROOM AND
LABORATORY
 Seat Pan Height
 Ideally, adjustable 40cm- 53cm from the floor to the top of the seat
pan.
 Seat Pan Depth
 Maximum seat pan depth 38cm-44cm
 Also provide a “waterfall” forward-sloping front edge on the seat
pan
 Seat Pan Width
 Minimum seat pan width 46cm

 Seat Pan Slope
 Adjustable 0 to -10 degrees
 Seat Back Tilt
 Minimum range 0 to 15 degrees
 Seat Back Height
 Minimum seat back height 36cm

DESIGNING THE PRODUCTIVE
SEATING IN CLASSROOM AND
LABORATORY
 Seat Back Width
 Minimum seat back width 30cm
 Armrest Height
 Between 15cm – 17cm above the centre height of the seat pan
 Armrest Length
 Minimum armrest length 15cm
 Armrest Width
 Minimum armrest width 5cm
 Armrest separation
 Between 46cm and 56cm.

WHAT ARE THE PRACTICAL
SOLUTIONS?
 Maintaining ergonomic seating in workplace
 Check whether workstation is set up well. Keyboard, monitor, and
person’s posture should be on straight line to avoid seating
discomforts
 To not look up at the screen. Adjust chair to look down at screen
instead
 Desktop to be at convenient height with enough space for
computer and papers
 Chair to give good support to user’s back with height-adjusting
options
 Keyboard and mouse mat to have good-wrist rest

Ergonomic seating- elbow angle
 Ensure that head and torso
are in-line with head
slightly bent forward, facing
towards the front, and
balanced
 Ensure that elbows are
close to body and bent
between 90 and 110
degrees

ERGONOMIC SEATING- FOOTREST
 Feet supported by a footrest
or relaxing on floor
 Ensure back supported fully
while leaning back or sitting
in vertical position
 Seat well padded to support
hips and thighs
 Ensure that knees and hips
in almost same height with
feet slightly forward

WHAT IS THE DESIGN FURNITURE
FOR CHANGE?
Seat design
 Basic size and shape of any seat determined largely by
anthropometric considerations:
 Seat height should not be greater than popliteal height of a small
user (5th percentile)
 Seat depth (from front edge to the backrest) should not be greater
than the buttock-popliteal length of a small user (5th percentile)
 Seat breadth between arm rests should give clearance for large
user (95th percentile hip breadth or elbow-elbow breadth plus
leeway). Seat breadth little less than hip breadth for seats without
arm rests
*popliteal: back part of the leg behind the knee joint

 Backrest designed to support weight of user’s trunk.
Backrest extend upwards, at least into shoulder region of
user

 Backrest angle determined by purpose of the seat. Angle of
100° to 110° from horizontal generally suitable for working
chairs and 110° to 120° for rest chairs. Seat surface should
be horizontal in a working chair or tilted backwards (by an
angle of 5° to 10°) in a rest chair

Shod feet flat on floor Clearance between thigh and underside of table for
freedom of movement

Clearance between back of legs and front edge of seat

 Chairs
 Should be stable throughout full range of postures that user adopts
 Five-point base of support suitable for rotatable chairs
 Seat surface should be substantially flat
 No part more than 25mm higher than any other
 Upper surface of front edge resilient or rounded
 Seat to be padded or upholstered
 Upholstery materials permeable to air and water vapour
 Backrest of office chair should provide:
 Adequate support for office worker in lumbar region
 Space for bottom and movements of shoulder blades
 Permit arm and elbow movement

 Tables
 length of desktop, table or worktop should be some multiple of
100mm and width, some multiple of 50mm
Preferred sizes are as follows:

Length of the desktop Width of the desktop

1200 600

1200 800

1600 800

 Working posture of person sitting at writing desk determined by:
 the height of the seat
 the height of the desk
 lesser degrees of adjustment adequate in real practice

CONCLUSION

 Deals with interaction of technological and work
situations with human being
 Basic human sciences involved are anatomy,
physiology and psychology
 Basic anatomy
 Basic anatomy is based on improving physical 'fit'
between people and things they use
 Difficult to achieve as need to consider range in human
body sizes across population

 Physiology
 Work physiology addresses energy requirements of the body and
sets standards for acceptable physical work rate and workload, and
for nutrition requirements.
 Environmental physiology analyses impact of physical working
conditions - thermal, noise and vibration, and lighting - and sets
optimum requirements accordingly
 Psychology
 Concerned with human information processing and decision-making
capabilities
 Increasing automation, while dispensing with human involvement in
routine operations, increases mental demands in terms of
monitoring, supervision and maintenance

REFERENCES
 Web-links
 http://safety.uchicago.edu/tools/faqs/ergonomics.shtml#heading1
 http://www.safetyoffice.uwaterloo.ca/hse/ergonomics/lab_ergo.htm
 http://safety.dri.edu/LabSafety/Appendix_F.pdf
 http://employment.alberta.ca/documents/WHS/OHS-WSA-handbook-laboratory-
workers.pdf
 http://www.ors.od.nih.gov/sr/dohs/HealthAndSafety/Ergonomics/atwork/Pages/lab
1.aspx

 Books
 Human Factors in Design, contributors Jim Sage, Alan Goodier
 Ergonomics: How to design for ease and efficiency, By K.H.E
Kroemer
 A resource guide for ergonomics
 Guidelines/ Code of Practice/legislation
 Occupational Safety and Health Administration (OSHA)
 Rapid Upper Limb Assessment (RULA)
 Anthropometry Analysis

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