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Office Ergonomics Guide 




/dibcna 

GOVERNMENT OF ALBERTA 



[ 


Digitized by 


the Internet Arcliive 








in 2015 







https://archive.org/details/officeergonomicsOOalbe 



TABLE OF CONTENTS 

1. INTRODUCTION 

2. THE BENEFITS OF ERGONOMICS 6 

3. GETTING STARTED • 7 

4. ERGONOMIC ANALYSIS - • • • 7 

5. TASK ANALYSIS • 8 

6. OFFICE EQUIPMENT • 9 

7. OFFICE FURNITURE • • • • 11 

(a) Seating • • 11 

(b) Work Surfaces 16 

(c) Footrests - • 18 

(d) Document Holder 18 

(e) Task Lighting 18 

8. WORKPLACE 19 

9. ENVIRONMENTAL FACTORS 21 

(a) Lighting 21 

(b) Noise 27 

(c) Thermal 28 

(d) Relative Humidity 31 

(e) Quality Of Air 32 

10. JOB DESIGN 35 

11. TRAINING 36 

12. GLOSSARY OF TERMS 37 

13. UST OF RESOURCES 39 

APPENDIX "A" - TASK DESCRIPTION FORM . 41 

APPENDIX -B" - WORKSITE SKETCH 43 



Prepared For: Occupational Health & Safety 
(Personnel Administration Office) 



Prepared By: Office Ergonomics Working Committee 

Marion Boon, 
Personnel Administration Office 

Debbie Bassett, 
Transportation & Utilities 

Nasrin Dhanani, 
Personnel Administration Office 

Va/ Fedorul<, 
Public Works, Supply & Services 

Sliaron Keily, 
Personnel Administration Office 

Ben Simon, 
Education 

Gerry Spratt, 
Personnel Administration Office 

Veronica Wake, 
Transportation & Utilities 



Sylvia Weber, 
Education 



INTRODUCTION 



Computers have become the dominant communication system in today's office. While computers have many unique 
features, they should be seen as part of an integrated work environment designed for human use. People are the 
limiting factor In this work environment. Since the use of computers is so dependent upon human interaction, it is 
important to design the workplace and the working conditions to meet the physical and mental needs of the 
computer user. The principles governing the design of the workplace to fit human form and function are known 
collectively as ergonomics. 

Ergonomics is the process of designing jobs to fit people. Jobs should be designed so that equipment, furniture, 
tasks, procedures and the environment (lighting, temperature, humidity, air quality and noise control) all come 
together to fit the needs of people in general, as well as the needs of the specific individual doing the job as 
described in Figures (1(a)) and (1(b)). 



"Ergonomic furniture and equipment however, is only good to the degree that its adjustability Is used on a 
regular basis by the user*. 



(Health problems of a muscular and visual nature are likely to occur if ergonomic principles are neglected in the 
design of the modem office. 



1 



The application of ergonomics to computer workstations requires participation of several key players: 



COMPUTER USERS can contribute by discussing their concerns with their supervisors. They can participate 
in training and apply the ergonomic principles learned on an ongoing basis. 



SUPERVISORS AND MANAGERS can become more knowledgeable about ergonomics and apply these 
principles In the workplace, not only in the initial stages but continuously through coaching existing workers 
and orientating and training new workers. 



DEPARTMENT ACCOMMODATION/FACIUTY PERSONNEL and purchasing agents also play an Important role 
In the application of ergonomics in the office. The accommodation/facility personnel should become 
knowledgeable about the ergonomic principles relevarttto providing suitable space, environmental conditions 
and the necessary utility services. Purchasing Agents should become familiar with the ergonomic aspects 
of the equipment and supportive furniture. 



It is essential for these key players to work together as a team to identify ergonomic problems in the office and 
develop strategies for resolution. 



2 



This Guide discusses the key ergonomic factors to be considered in the design of worl<stations and environments 
where computers are required as part of the work perfomied. The organization of this GukJe is based on several 
assumptions. 



1. The Guide will be used by people confronted with the task of assessing or planning a particular workplace, 
for example supervisors, managers, accommodation/facility personnel and purchasing agents. 

2. Users of the Guide will want to avoid technical explanations and terminology. Therefore, technical tenns 
have been avoided except where essential. A 'Glossary of Terms' has been included at the end of this Guide 
for reference in defining certain technical terms. Those who wish more detail, should refer to the CAN/CSA - 
Z412 - M89. ^Office Ergonomics A National Standard of Canada' 

(see Resource Section). 

3. The Guide will be considered as a comprehensive set of principles applicable in a given workplace. The total 
document is needed to adequately assess and design a computer workstation. 

4. The Information in this Guide reflects the most recent findings relating to the use of computers. Changes 
are to be expected in such a rapkJIy evolving field. These changes will be considered and where 
appropriate, included in future editions of the Guide. 



3 



THE HUMAN - TASK - ENVIRONMENT SYSTEM MODEL 



Training 



Environment 





Organization 




Information 





Worker 




Action 







Equipment 
and Materials 




Figure 1 (a) 



COMPONENTS OF HUMAN - TASK - ENVIRONMENT SYSTEM 



4 



Equipment and Furniture together with the Task 
determine the demands that will be put on the person. 



Infomiation 




Action 



Information must be detected by the senses, recognized 
and then evaluated. Information presentation must match 
our sensory systems and the way our minds work: only 
then will recognition and evaluation be reliably smooth and 
accurate. 



Every Person Differs in shape, size and experience. The 
best worksite will adjust to the different physical needs of 
every user. 



Activity Patterns are associated with every type of job. 
Consideration of reach, force, range of movement, and 
frequency of movement will result in work which is 
convenient and provides variety in exercise, without 
excess. 



The Physical Environment requires careful consideration 
so that visual, acoustic and thermal needs are met for 
comfort and performance. 




The Training Environment should ensure quick and 
accurate acquisition of critical skills and knowledge. To do 
so, ft must consider the characteristics and existing skills of 
the newcomer in determining learning objectives arKJ 
methods. 




The Organizatk>nal Enviroriment which can minimize 
monotonous work and offer social interaction, will be one in 
which any of us would be pleased to work. 



Figure 1 (b) 



5 



THE BENEFITS OF ERGONOMICS 



When ergonomics is applied in the design of jobs, there are several benefits that make the investment 
worthwhile. For the worker It means: 

• better designed workstation; 

• Improved environmental conditions; 

• less fatigue and discomfort; 

• elimination of excessive physical loads or stressful repetitive movements; 

• Increased feelings of health and well-being; 

• improved overall health and safety; 

• more feelings of control; 

• reduced mental stress. 

But there are benefits for the employer also, and they include: 

• increased productivity; 

• Improved quality control; 

• Increased availat)le work force by reducing absenteeism 
(prevention of repetitive strain Injuries); 

• less prot>ability of error and acckJents; 

• better morale amongst workers; 

• commitment to the job. 

COSTS WILL ALSO BE I^SS If ergonomics is applied eaiiy in the planning stage. The Immediate cost may 
t>e high, but the long-term gain is significant. Compensation costs for musculoskeletal injuries and visual 
problems are reduced significantly when ergonomic principles are applied in the planning and operating 
stages of a job. If ergonomics is applied as a reaction to serious prot)lems after an office system is 
operational, costs will be significantly higtier for r^itting. 



6 



GETTING STARTED 



The application of ergonomics depends on a systematic approach. All the elements in a system must fit together 
to forni a smoothly functioning operation. This need not result in extra expense. 

Rather than rushing to replace just one "obviously" deficient item In a person's working environment, consider all 
the elements that make up their job. Although this will seem more time consuming in the short term, It will increase 
the chances of success in the long term. 

In other words. IF YOU ARE GOING TO DO IT, DO IT RIGHT THE RRST TIME! 



A practical way to do this is to conduct an ergonomic analysis of an existing workstation or when a new workstation 
is being designed. 

In the following pages you will find key information to help you In planning, developing and/or refitting ergonomic 
workstations in the office. Your Department Accommodation/Facilities contact person will assist you. 



ERGONOMIC ANALYSIS 



Effective application of ergonomics requires a thorough analysis of the demands the work system places on each 
worker, the way adjacent jobs affect one another, and the effect of the environment. Effective analysis of task 
demands requires working closely with the people who do the work, professionals with appropriate expertise, and 
the managers who set the boundaries within which the work system has to function. It is important to remember 
that in applying ergonomic principles to the work system, the preferred approach is to fit the job to the person. This 
can be accomplished through proper design of equipment, fumlture, work environment, workstation layout, work 
procedures, and provkJIng operator training. An 'Office Ergonomic Checklisf is available from your department 
accommodation/facilities contact and will assist you in designing an ergonomic workstation. 



7 



TASK ANALYSIS 



Most jobs are composed of several tasks. The first step In the ergonomic analysis of a particular job is to break It 
down Into Indlvklual tasks. For example, a receptionist's task may be to operate a desktop computer, file 
documents, answer the telephone, and direct visitors. In tum, each task can be divided into a number of activities, 
such as reaching for a file and labelling It (see Figure 2 and Figure 6). 



Operate 
a word 
processor 



Receptionist 



Job 



' 1 

File 1 


Direct 




Answer the 


documents 


visitors 




telephone 

















Tasks 



Activities 



Reaching Labelling a 
for a document 
document 



Reading a Sorting or 
document organizing 
a document 



etc 



etc 



Figure 2: Job Breakdown 

Using the Task Description fomn (Appendix "A"), list the tasks associated with each job and the percentage of time 
that the worker spends on each task. In the comments column, note any tasks that demand awkward postures, 
repetitive movements, or long reaches. Record any comments the workstation user may have. This Information will 
be required In conjunction with other data gathered along with a floor plan sketch (Appendix "B") to make decisions 
of how to set up a proper wori<place (see page 19). 



8 



OFFICE EQUIPMENT 



In the automated office, computers with visual display screens, keyboards, printers and other special accessories 
are used for handling, processing, storage, retrieval and distribution of infomiation. This requires an interface 
between equipment and the user. To maintain acceptable performance levels, the needs and limitations of each user 
should be recognized and satisfied by the equipment and the environment. Office equipment should be selected 
for ease of: 

• use; 

• installation; 

• operation; 

• maintenance. 

INSTALLATION IS EASIER IF THE EQUIPMENT IS: 

• lightweight or designed to be moved easily (handles); 

• provided with features that promote proper positioning or mechanical connections; 

• provided with instructions that are easy to follow. 

Appropriate wire management (the use of troughs) should be used to install the electrical, telephone, and coaxial 
cable services. The equipment should be equipped with the proper cords and cables of sufficient length to allow 
flexible placement. To prevent tripping hazards, excess cords and cat)les should be rolled up and stored neatly 
k)ehind the equipment and kept out of the walking areas. 



9 



Ease of operation requires that displays are functionally designed so that they are easy to read or hear and provide 
the proper Information. Controls should be grouped by sequence of function and easy to Identify and reach from 
the operating position. 

Maintenance requires less time to complete and Is less prone to error if the equipment has been designed so that 
maintenance functions are easy to find and readily accessible. Proper Installation of the equipment should also be 
considered to ensure that maintenance functions can be easily reached and are well lit. 

Assistance in procuring office equipment that meets ergonomic standards is available from your Department 
Accommodation/Facilities contact person. 



For further information on the selection of proper ergonomicaliy designed visual display terminals, keyboards, 
and screens, refer to Part 4 of the CAN/CSA Standard for Office Ergonomics referenced on Page 3 



10 



OFFICE FURNITURE 



Office furniture has to support the user s body, the office equipment, and the work material. This includes the chair 
and work surface (table), and stationery Items like the footrest and document holder. 

Office workers spend long periods of time at their workstations and the effects of poor posture can cause 
musculoskeletal strain and Injuries, visual fatigue and Wood circulation problems. 

Consideration must be given to the proper selection of office fumlture and Its an^ngement so as to form a safe and 
efficient workstation. 

Every worker should have a work space that conforms to indivklual differences in size and shape and 
accommodates task demands without risk of pain or injury. An ergonomic workstation provkJes for seating, work 
surfaces, storage and foot support. 

(a) SEATING 

Seating should be of a design to meet the task at hand, provide a comfortable and stable support for the duration 
of the working day and be compatible with the other fumlture. The specific seating characteristics to be considered 
when selecting a chair are outlined on the next page and In figures 3 and 4. 



11 



A Chair 



^ Seat Pan 

Width -at least 450 mm (18 in.) 

Height - adjustable with a range of 380 - 520 mm (15 - 20 in.) above floor 

Depth - between 380 - 430 mm (15 - 17 in.) 

Slope - adjustable between 3° fon/vard and 4** back 

Seat - should have "waterfall" slope on front edge with no sharp edges 

Cushion - compression of about 25 mm (1 in.) and minin^l contour 

A Seat Back 

Width - between 350 - 480 mm (14 - 19 in.) 

Height • adjustable between 380 - 530 mm (15-20 in.) from top of backrest to top of seat pan 
Angle - vertical tilt between 95** - 1 10° 

Shape - curved in the vertical and horizontal planes with maximum indentation of 40 - 50 mm (1 .5 - 2 in.) 
A Seat Covering 

' penneable, non-slippery fabric 

- allows ventilation and absorption of perspiration 

- no seams, buttons or folds that cause pressure points 



12 



Armrests (optional) 



Apart - minimum of 450 mm (18 In.) between inside edge 

Height - between 200 - 250 mm (8-10 in.) from top surface to top of seat pan 

Width - minimum of 50 mm (2 In.) 

Length - minimum of 150 mm (6 In.), not to extend beyond 300 mm (12 In.) from front of backrest 

Detachable - cantilever armrests retrofittable to existing chairs 



A Controls 



Controls can be either cylindrical or paddle or rotary for chair adjustments. They should be easiy aooessiie 
and adjustable from the sitting positions. Recommended specifications for controls: 



Cylindrical handle on levers for lateral 
movement 

Paddle handle 

Rotary control 



25-38 mm (1-1.5 In.) in diameter 

Paddle handle 50 mm^ (2 In.^ minimum area 
Rotary Controls 50 mm (2 In.) minimum diameter 



A Chair base 



The base of the chair should swivel through 360° and have hard casters for soft floor surfaces and soft 
casters for hard floor surfaces. The chair should have a five-pronged base with casters and a base diameter 
of 400 -450 mm (16 - 18 In.). 



13 



Figure 3: 
Front View of Chair Dimensions 



Seat back width 
35CM80 mm 



Minimum 
armrest 
width 
50 mm 

M 




Minimum 
armrest 
height 
200 mm 



Compressed 
seat height 
380-520 mm 



14 



Figure 4: 
Side View of Chair Dimensions 




For further Information on the selection of ergonomic seating, consult with Design Standards and Furniture Branch, 
PMS.S. through your Department Accommodation/Facilities contact person or refer to Part 5 of the CAN/CSA 
Standard for Office Ergonomics. 

(b) WORK SURFACES 

The work surface should be designed to provide the opportunity to place all material and equipment required to 
carry out the normal tasks, keeping in mind the spans of reach by the user to perform each task. 




Figure 5: Attemative Computer Configurations 



16 



A horizontal work surface in the automated office usually has to accommodate a computer terminal with a keyboard, 
an area for writing and tabulating, an area for communication equipment, space to accommodate a printer and 
storage of resource material and computer accessories. In such cases, wrap around angled workstations will be 
more appropriate than rectangular ones (see Figure 5). This configuration allows free movement along the desk 
line with little obstruction to leg movement. 

Not all the work surface area needs to be accessible in the same horizontal plane. Frequent or heavy reach 
requirements should be placed close at hand and more occasional requirements may be place further away or on 
a different horizontal plane (shelves). 

A Work Surface Needs 

Work surfaces should allow for: 

- Repositioning of the computer screen and keyboard as required to accommodate the person and 
the task. 

- A separate work surface for the keyboard Independently adjustable for vertical height. 

- Placement and use of accessories such as document stand, task lighting (if required), telephone, 
trays, card files, printer, etc. 

- Placement of source and reference documents. 

- Storage of accessories and personal Items. 



17 



Since optimal writing height, keying height and screen viewing height will differ for each user, each height should 
be easily and Independently adjustable from the sitting position (see figure 5). 

The work surface should be thin enough and high enough to provide clearance for the thighs between the chair 
surface and the underside of the wori< surface. 

(c) POOTRESTS 

Footrests should be used If the operator's feet cannot be placed flat on the floor when the seat height is properly 
adjusted. The footrest should have an upward slope between 10" and 20°, at least 300 mm (12 In.) wide by 300 mm 
(12 in.) deep, and be covered with a nonslip material. It is recommended that a footrest be available for every office 
workstation. 

(d) DOCUMENT HOLDER 

Frequently viewed copy material for data entry should be placed at the same height and distance as the screen and 
situated as close to the screen as possible. This can be done by using a document holder which will minimize head 
and body movement. 

(e) TASK UGHTINQ 

Task lighting is a separate light system used to supplement ambient lighting levels in order to optimize the 
perfomnance of visual tasks. This can be achieved by adding a small lamp to the workstation that can be positioned 
to provkJe illumination directly on a specific task. The lamp should be able to be adjusted so the light will not cause 
glare. 



18 



WORKPLACE 



The placement of people and equipment In the workplace should minimize distances Ijetween components that are 
important to each other or frequently communicate with each other, and the number of times personnel cross each 
other's paths. Some equipment may have special space requirements and need increased air flow to remove heat. 
Consideration must be given to sufficient space for freedom In entering and exiting from the workstation. 



With the information gatfiered in ttie Task Analysis, (see page d) a floor plan sketch (see Figure 
6 and Appendix 'B') of the workplace should be completed. Pay attention to and indicate the 
positions of doors, windows, lights, equipment, and furniture. 



The connecting lines or links between personnel, equipment, and fumiture that represent the dally movements of 
each office worker should be drawn on the floor plan sketch (see Figure 6). Identify the degree of importance of 
each link as high "H", medium "M", or low 'L' depending on how frequently the worker moves between locations or 
how essential the link is. Attention should be directed to reducing the length of the high priority links. 



19 




Figure 6: Link Analysis of Office 




Figure 7: Rean^ngement of Office with Lini<s Redrawn 

Examine the sl<etch to determine if rearranging the equipment or fumiture can further reduce distances and crossings 
of people. 



20 



ENVIRONMENTAL FACTORS 



Environmental factors such as lighting, noise, themial conditions, ventilation, and air quality influence the office 
workplace and the people working there. 

(a) UGHTINQ 

^ General 

Lighting for the electronic office containing computers is a complex issue. This is due to the nature and mix of visual 
tasks involved. Simple parameters such as the amount of the light at the workstation are not enough to address 
the problems associated with workstation lighting. Some basic gukJance follows but for more information or advice 
the reader is directed to the following resources: 

A Standards 

Illuminating Engineering Society of North America (l£.S.) 
Lighting Handbook - Application and Reference Volumes 

- Recommended Practise for Lighting Offices Containing Visual Display Terminals # lES RP-24-1989 

^Resources 

Electrical Engineering Branch. Technical Resources Division. 

- Alberta Public Works, Supply and Services 



21 



A Visual Task 

Electronic offices contain a mix of computer and paper based visual tasks. Each task has Its own particular 
requirements for lighting, some of which are mutually exclusive. Proper lighting for this type of work space involves 
striking a balance amongst the requirements for the various tasks. 

A Computer Task 

The computer task can be of three basic types. Viewing illuminated characters against a dark background, viewing 
dark characters against an illuminated background or viewing illuminated characters and background of contrasting 
colors. Because the task itself is illuminated, the brightness of the task and any light falling on the task from the 
environment will affect task visibility. Proper task visibility requires a balance between task brightness, surrounding 
brightness and screen illumination. Ughting must take vertical task orientation into account. 

A Associated Paper Task 

Paper tasks associated with computers are generally the same as for normal office space. They range from pencil 
on grey paper to high contrast print on white paper. Task orientation may be either vertical or horizontal. 



22 



Age of Viewer 

As we age, the ability of our eyes to adjust to different focus lengths and light levels decreases. This means that 
lighting levels and control are more Important for older age groups. Lighting levels and designs for Government 
offices should be aimed at an age group of 45 to 65 years. 

A Amount oi Light (illuminance) 

The amount of light is not the most critical component of proper lighting at a computer workstation, however there 
should be enough light for the paper based task without so much light that the computer task Is washed out. Since 
paper based tasks still form a significant part of nomial office work, lighting levels should be suitable for such tasks. 

Lighting levels are measured using an illuminance meter. They can be measured in Footcandles (Fc) or Lux. 
Measurements should Include Illumination on vertical as well as horizontal surfaces. Acceptable lighting levels fall 
into a broad range of values. Lighting levels recommended by I.E.S. and P.W.S.S. are as follows: 





I.E.S. 


















Horizontal - 550 to 1,100 Lux (50 to 100 Fc] 
Vertical - 330 to 750 Lux (30 to 70 Fc) 


) 

























23 



A APMS.S. 



Standard lease and design requirements documents require a minimum liorizontal Illumination of 750 lux on the 
desktop. All areas of an office are not required to meet this minimum so some variation Is pemiisslljle. 

It should be noted that Inexpensive light meters are generally of low accuracy and should not be used to make 
decisions regarding changes to the lighting system. 

A Brightness puminance) 

The ratio between the brightness of the various surfaces in the field of view has a nfiajor effect on task visibility. 
Brightness ratios should be conskiered in the assessment of the lighting system. 

A Direct Glare 

Bright sources such as windows and light fixtures In the direct field of view can cause visual discomfort and reduce 
task visibility. This problem can be eliminated or reduced by: 

controlling the brightness of such sources; 

orientating the workstation so the glare Is removed from the direct field of view; 
the computer operator not directly facing a window or other bright light source; 
shielding the source from direct view; 
using blinds on windows. 



24 



A Veiling Rejections 

Reflections of bright sources or light colored surfaces off of the surface of the task will reduce task contrast and 
visibility. This Is particularly noticeable with computer screens due to their highly reflective surface and low 
brightness relative to the reflections. 

Types 

Reflections can occur in the computer screen, off glossy paper or off shiny type on matte paper. These reflections 
can be either well defined (specular) or diffuse. They can occupy small areas or cover the entire task. With 
computer screens, reflections can occur on the protective glass surface as well as the CRT tube Itself which presents 
a double image. 

Sources 

Reflections can be caused by bright windows, light fixtures, bright parts of walls or partitions or light colored clothing. 
Even an evenly lit ceiling can be a problem if It Is too bright or the tilt of the screen Is wrong. 

Control 

Reflections can be controlled by workstation orientation, screening the light source or reducing the reflectivity of the 
task. 

The computer should not be placed so that the operator faces either towards or away from a window. Screens 
should be at right angles to windows and other bright surfaces. Also the workstation should be placed so that light 
fixtures are to the skies rather than over, behind or in front of the screen. 



25 



The screen shoM be fitted so that its surface is vertical in order to eliminate reflections of light fixtures. This 
usually also requires that the screen 6e placed at a level such that ttie top of the screen is at the same height as 
tfie eyes. Sometimes minor adjustments in screen tilt or rotation are erxMjgh to eliminate r^ections and improve 
tasic visitMlity. 

A Lighting Fixtures (Ijjminaires) 

Much office space used by the Government was buitt prior to the advent of large scale computer use and as such 
the light fixtures and layout were not designed for computer applications. Most lighting systems use direct 
fluorescent luminaires with standard diff users. These can be a source of direct and reflected glare. Workstation and 
screen orientation is the simplest way to resolve these problems but In extreme cases some modification of the 
lighting system may be required. 

Space for computers should be lit using either Indirect or direct/indirect systems, low brightness (parabolic) 
luminaires or luminaires with low brightness diffusers. Most new office space Is designed this way. However, for 
cost and other reasons, retrofits to existing space requires extensive analysis before proceeding with major changes 
of this type. 

A Computer Equipment 

Most newer computer screens are designed with glare reducing surfaces and tilt/swivel bases. This reduces 
reflection problems somewhat and makes adjustment easier. 

The use of anti-glare filters or coatings on older screens Is of questionable merit. Firstly, these reduce the brightness 
of the visual display causing them to be driven at higher than normal levels for good visibility thus shortening their 
life. Also, filters often Introduce another reflection Into the visual field which may make the problem worse. These 
devices are only recommended as a last resort. 



26 



(b) NOISE 



Most of the complaints received about noise in offices are related to noisy printers and other pieces of office 
equipment. Such noise sources should be assessed to determine what levels are being generated to cause the 
distraction and why. Some complaints may result because of excessive Interference with verbal communication, 
either face to face or over the telephone. Others may complain because tasks that require concentration are more 
difficult to conduct In the presence of certain noises or that the noise is simply annoying. 

In situations where concem is primarily due to office equipment, the noise levels should be surveyed with a sound 
level meter, using the A-weighted scale. The measurement results are then evaluated to determine the specific pieces 
of equipment causing the major amount of noise. Some methods of effectively controlling noise Include placing the 
noisy equipment in an enclosure e.g. cabinet or room, or by increasing the distance between the source and the 
worker. Another method Is substitution of a noisy piece of equipment with less noisy one e.g. laser printers. 

Work requiring high levels of concentration should be conducted in a room isolated from the general office area 
where the noise is present. 



For further Information on reducing noise In the office setting, consult whh your Accommodation/Facilities 
contact person or Department occupational health and safety office. 



27 



(c) THERMAL 



Thermal comfort, In an office environment, generally relates to an acceptable combination of air temperatures, 
ventilation and fresh air rates, relative humidity and quality of air. 

No two people will react to a set office environment in the same fashion. Some like a cool working environment, 
some like a wamier working environment, others enjoy the feeling of air pulsating on them, while others object to 
any type of drafts. Workers generally dislike a stagnant air condition, and low humWity. 

An optimum office environment would be one that could be controlled Indivkiually by each and every office occupant 
according to their own personal preference. Economically, the optimum office environment would be very costly 
to provkJe. The goal is to provkJe a comfortable environment for workers. 

Thermal comfort conditions that are generally acceptable to the majority of people have been kJentified. The key is 
to provkie these conditions at as constant a level as possible through the various seasonal cycles, on a day to day 
basis, as well as. on an hour by hour basis, through the course of a thermally changing day. 



28 



STANDARDS 



' ASHRAE 

ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) sets the standards 
to which ail ofTice environments are designed in North America and most of the rest of the worid. The Alberta 
Govemment. in design of new office buildings, not only uses these standards, but is more specific on some of 
its conditions. 

- Alberta Building Code (ABC) 

The Alberta Building Code states that "l-ieating. ventilating and air-conditioning systems shall be designed to 
confonn to good engineering practice such as described in the ASi-iRAE l-landbooks". 

A few of the ASIHRAE standards are cited in the following sections: 

A Tempefatures 

Temperature is the only themnal comfort condition that can generally be controlled from within the office space by 
adjustment of a thermostat. 

Alberta Govemment offices are designed to provide a temperature of 22°C. During summer months (cooling 
season), it is nom^ to expect temperatures to range from 22°C to 24°C. These are the ideal or 'design' conditions. 



29 



Ventilation 



Air should be distributed to all office areas or wori<stations. The greater the degree of heat generating equipment 
such as computers, copiers, etc., the greater the amount of air required to cool the workstation (i.e. to remove the 
heat). 

In certain instances where groupings of computers and computer processing equipment occur, additional (or 
separate) air conditioning equipment may be required to remove this added heat. 

ASHRAE's latest standard recommends that office areas (newly designed facilities) be provided with a minimum of 
10 L/S (litres per second) per person of fresh air. This means that the ventilation system provides this amount of 
filtered outdoor air for every occupant plus the amount of ventilation air (recirculated air) required to provide the 
necessary air conditioning. 

Older ventilation systems may not be able to supply the amount of fresh air mentioned above as standards were 
not as high previously. 

Supply air outlets (generally at the ceiling) are usually located strategically to provide as best a distribution to an 
office space as possible. Air should be directed along the ceiling or in a manner such that drafts are eliminated. 

If changes are made at any time to the office floor plan with items such as fumiture. acoustical screens, wall changes 
or partitions; it should be accompanied by a re-evaiuation of the air distribution, e.g. relocating ceiling air outlets, 
adding others, or reducing air flow. 



For further assistance, contact your ACCOMMODATfON/FACIUTIES contact person. 



30 



(d) RELATIVE HUlilDITY 



Relative humidity (R.H.) refers to the percentage of moisture in the air. For example, a lower percentage of R.H. 
will Increase the rate at which moisture evaporates off the sl<in. giving a person the feeling of coolness. This is why, 
In our dry dlmate, during the winter months we tend to raise the temperatures slightly In offices and homes to 
compensate for the coolness effect. 

Low humidity can also cause other discomforts, such as nose, throat and eye Imtation and can contribute, as some 
reports indicate, to increased incidents of colds and flu. It can also contribute to the build-up of static electricity 
which could affect the operation of electronic equipment (computers) and paper feed on printers and copiers. 
Grounded type static pads are placed under keytx)ards or computers to discharge static electricity build-up. 

Alberta Public Works. Supply and Services gukie for new facilities recommends 15% R.H. at -QS^C, Increasing 
proportionally to 25% R.H. at +5°C and greater than 25% R.H. at higher temperatures. Higher humidity levels at 
lower temperatures will result In condensation forming on windows with detrimental effects on the building structure. 

(Based on the aboim gukMmes, mlativB hurnkfitywa sm b0 



31 



(e) QUALITY OF AIR 



The consideration of air quality is an important factor in acceptability of office environments in terms of 
woricer health, comfort and performance. 

Office buildings can contain a wide variety of contaminants, but the common airtx)me contaminants are carbon 
dioxide. cartx>n monoxide, formaldehyde, and respirable dust particulates. Other contaminants mentioned often, 
such as allergenic fungi, and Legionnella bacterium, are more common in high humidity environments. Radon gas 
has not appeared to be a problem with the type of subsoil conditions we have on the prairies. Ozone can be a 
concern in printing shops and in inadequately ventilated photo copying areas. 





The feeling of stuffiness, due to lack of adequate \ 


fresh 


air and < 


:irculation of air, is 


perhaps the most common 




complaint encountered 
contaminants. 


in a 


typical 


office 




Odours 


1 


Tiay signal 


the 


presence of chemicals < 


3r other 



Alberta Public Works, Supply and Services gukJe, as mentioned above require a minimum set amount of fresh air. 
In addition, almost ail govemment owned facilities utilize a *free-cooling' concept for ventilation. This means that for 
the greater part of the four seasons, buildings are cooled using outdoor air (fresh air). Therefore all or most of the 
air is circulated only once and then exhausted, provkiing an almost outdoor atmosphere within. 



32 



A Cartxxi Dioxide 

Carbon dioxide (COj) occurs naturally at about 350 ppm (parts per million). At higher levels. It has pros/en to be an 
excellent Indicator of ineffective ventilation. A reading of up to 8CX) ppm CO2 (adopted as the Government standard) 
indicates an acceptable supply of fresh air. 

A Cwton Monoxide 

Carbon monoxide (CO) is a product of incomplete combustion. Generally buming tobacco (cigarette smoking) is 
the major source of carbon monoxide in the office. Another common source may be automobile exhaust fumes 
entering the building through low level air intal<es or from attached car paricades that are not ventilated sufficiently. 
Symptoms of exposure to moderate levels of cartx)n monoxide include headaches and dizziness. 

A Formaldehyde 

Formaldehyde is one of the many volatile organic compounds found In the office environment 
Formaldehyde Is present in some new construction materials, particle board fumlture. new carpet and carpet 
backing, some aerosol sprays and urea-fomnaldehyde cleaning agents. Allowing sufficient time for 'curing' or 'off 
gasing' and higher levels of ventilation after materials are installed will decrease the levels of formaldehyde vapours. 

The most common noticeable ill effects are eye, nose, and throat irritation, respiratory disorders, and allergies. 



33 



A Dust Particulate 

Dust particulates are particles of dust that have been generated from many sources such as paper, copy machines, 
household lint, dust from outdoors, carpets, clothes, etc. 

Dust particulate can best be controlled with high efficiency fresh air filters and good housekeeping management. 
^ Older And Ljeased Facilities 

Older owned or leased facilities may not be able to meet present day guides. 

For example, previous ASHRAE guides for fresh air were one half (50%) of those required presently. 



For further Information on thermal comfort and air quality consult with your 
Accommodations/Facilities Contact person or refer to Part 8 and 9 respectively of the 
CAN/CSA Standard for Office Ergonomics. 



34 



JOB DESIGN 



Increased automation has changed many office \obs. Automation has often led to jobs that require sitting or 
standing In one position for long periods while doing repetitive tasks. This causes health problems including 
musculoskeletal strain, visual fatigue, restricted Wood circulation, and stress from lack of or too much mental activity. 

Well designed office jobs: 

• minimize energy expenditure and force requirements 

• balance tasks and provkJe changes in body position and mental activity 

• allow some decision-making so workers can vary activities according to personal needs, 
work habits and circumstances In the workplace 

• give workers a sense of accomplishment 

• provide good work/rest schediies 

• provkJe feedt)ack to workers about how they are doing 



Preventing Job Design Problems 

Ensure that workers take regular rest breaks. Encourage workers to stand up. move around and 
change mental activity during rest breaks. Changing the activity and/or performing simple (short) 
exercises (muscle and visual) at the workstation eases muscle aches and eyestrain. 

Vary work task. Break up computer work with non-computer tasks to ensure change in body 
position and mental activity. 

Set a reasonable work pace. Working too quickly contributes to muscle strain. Working too slowly 
contributes to boredom. 



35 



TRAINING 



Training may be Indicated by a variety of factors. Training Is likely to be needed when a new employee enters the 
organization, or on an ongoing basis to refresh the skills of longer-term employees or If they are experiencing injuries 
during the operation of computer. Training will be needed when new technology is Introduced. Effective training 
can result In Improved health and safety, higher job satisfaction, better perfomriance and enhanced employee 
development and growth. Depending on the nature of the training needed, different types, levels, and methods of 
training will be required. 

Effective training for the new office technology should: 



A provkje for a dear understanding of the technical operation of the equipment 
A show how the job to be accomplished relates to the oi^anizational mission 
A define the new job responsibilities 

A provkie knowledge on ergonomic and environnriental factors and skill in the operation of the 
ergonomically designed equipment, furniture and workstatkm. 



Not only do the operators of the new electronic equipment require training, but also managers and supervisors. 
They need to know what the new equipment is or is not capable of. as well as the human and policy issues 
surrounding its use. 

Task related training pertaining to the operation of the equipment is available from equipment suppliers and should 
be arranged for at the time of purchase of the equipment. Contact your Department Occupational Health and Safety 
Office to get assistance in obtaining training related to the implementation of the new office technology, the 
application of ergonomic principles, and the proper use of ergonomic fumiture. 



36 



GLOSSARY OF TERMS 



In this guide, the meaning of certain words are defined below 



ASHRAE 



stands for American Society of Heating, Refrigerating and Air- 
Conditioning Engineers. 



Acoustical Screens 



movable freestanding screens constructed of sound absorbing 
material, usually fabric and used to form portable walls around 
fumiture in open office areas. 



Connection Unes 



lines drawn to show activity links and movement of a worker 
between equipment and fumiture in a work area. 



Cumulative Trauma 
Disorder 



see Repetitive Strain Injury. 



Equipment 



includes electronic devices used in the office - visual display 
terminal, central processing unit, keytx)ard, plotter, printer. 



Ergonomics 



the matching of task demands to human capabilities to improve 
worker capacity and well being. It involves the study of the 
interaction t)etween people, their task, the environmental 
conditions, equipment and fumiture in the workplace. 



Fumiture 



fumishings used to support the computer user's body, office 
equipment and work material and includes chair, work surface and 
storage shelving. 



Musculoskeletal 



refers to the bones, muscles, tendons and ligaments which provide 
support and strength for the body and allow movement 



Repetitive Strain 
Injuries (R.S.I.) 



is a collective term for a range of conditions characterized by 
discomfort or persistent pain in musdes, tendons and other soft 
tissues of the human txxiy. R.S.I is usually caused or aggravated 
by repetitive motions, sustained or constrained postures, and 
forceful movements. In the office environment, R.S.I, usually affects 
the wrist, eltx)w. shoulder, neck or lower t)ack. (Also called 
cumulative traunria disorders (C.T.D.) or occupational overuse 
syndrome (O.O.S.) 



GLOSSARY cont; 



Stationery Kerns 



items not considered as office furniture and not included in 
P.W.S.S. Standard Furniture Catalogue, e.g. document holder, 
footrest. etc. 



Task Lighting 



a light fixture which provides localized illumination upon a specific 
tasl((s). 



Visual 

Fatigue/Discomfort 



symptoms of discomfort or pain Involving the eyes. Includes 
irritation, buming, pain, blurring of vision, headaches, difficulty 
focusing, tiredness of the eyeball. 



Volatile Organic 
Compounds 



substances composed of two or more elements one of which 
contains cartx)n, joined togetiier chemically. 



Wire Management 



the responsibility of organizing the necessary wiring and cable to 
an electronic wori<station including the distribution of the electrical 
systems within the wortcstation. 



Workplace 



the whole office area, including groups of workstations, common 
rooms, storage and equipment areas. 



Workstte 



a location where a worker is engaged in an occupation. 



Workstation 



the space occupied by one indivkJual working independently or a 
small group of people working as a team and siiaring information 
and support equipment on a continual basis. 



Worksurface 



the surface upon which the indivkJual can write and support 
reading material and equipment. 



LIST OF RESOURCES 



Literature 

• A Guideline on Office Ergonomics, A National Standard of Canada, CAN/CSA-Z412-M89 

• People and Productivitv . A Manager's Guide to Ergonomics In the Electronic Office. 
Marvin J. Dalnoff and Marilyn Hecht Dainoff 

• Govemment of Alberta Personnel Policies and Procedures, Directive 12-15 
Facility Environmental Concerns, and Directive 12-17 - Office Ergonomics 

• Alberta Occupational Health And Safety Library 
Technical Services 

• Department Accommodation/Facilities contact person 

• Department Occupational Health and Safety Office 

• Occupational Health and Safety Branch, Personnel Administration Office 

• Design Standards and Fumiture Branch, P.W.S.S. 

(accessed through Department Accommodation/Facilities contact person) 

• Alberta Occupational Health And Safety 

Training 

• Department Staff Development Officer 

• Department Occupational Health and Safety Office 

• Occupational Health And Safety Branch, Personnel Administration Office 



40 



APPENDIX "A" 
TASK DESCRIPTION FORM 



Location: 

Job: 

Plan/Analysed by: 

Date: 

Task Description: 



Tasks 


Priority of Tasks 


Effort(%work time) 


Comments 



























































































































































41 



42 



APPENDIX -B- 



WORKSITE SKETCH 



Sketch here the floor plan of the worksite. Don't worry about scale but write in all important dimensions. Note the 
position of doors, windows, lights, and frequently used or obstructive equipment and fumiture. Computer 
workstations should be clearly identified. 



43 



44 



iNdiiuiidi Liurary OT oanaaa 
Bibliotheque nationale du Canada 




3286 51967208