2nd Edition
(Revised)
Canadian Centre for
Occupational Health and Safety
Summary
Indoor air quality (IAQ) is a recently recognized concern.
In the 1970s energy conservation programs were encouraged
in the USA and Canada. Ventilation rates were reduced and
buildings were sealed to limit the entry of untempered
outdoor air into buildings.
IAQ problems occur in buildings where chemical or
biological contaminants build up to levels that can
adversely affect some occupants. The following are some
commonly reported health effects: headache, nausea,
fatigue, drowsiness, dizziness, respiratory problems,
chest tightness, dry throat, skin rashes, dry and itchy
eyes, stuffy nose, runny nose, loss of concentration and
general malaise. These symptoms are collectively known
as Tight Building Syndrome (TBS). A well-known IAQ
problem is building related illness (BRI). BRI is associated
with a distinct set of symptoms and clinical abnormalities
which are recognized as real occupational health conditions.
Workplace conditions such as noise, inadequate lighting,
inadequate thermal environment, and ergonomic problems
can cause discomfort that is sometimes falsely attributed
to chemical or biological contaminants in the air.
In the past, symptoms reported by building occupants
were often considered psychological because the
symptoms seemed variable and subjective, and because
an exact cause could not be identified.
Today, IAQ problems can be identified through workplace
inspections and an analysis of worker health complaints.
It is possible to control many health symptoms through
effective building maintenance programs and by
controlling specific air contaminants and their sources.
This Guide outlines how to identify potential IAQ problems
and how to take steps towards controlling these problems.
Actual recognition and control of IAQ problems may
require specialists and a team approach involving complex
measurement, analysis and implementation of controls.
Table of Contents
Section I Indoor Air Quality (IAQ): An Occupational Health
Concern
1. Commonly Asked Questions . . . . . . . . . . . . . . 2
2. Why Do We Worry About IAQ? . . . . . . . . . . 6
Multiple Chemical Sensitivity . . . . . . . . . . . . 7
Chemically-induced Hypersensitivity . . . . . . 8
Section II Sources of IAQ Problems
1. What Are the Possible Causes of IAQ
Problems? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Lack of Outdoor Air . . . . . . . . . . . . . . . . . . . 10
Air Contaminants from Inside the Building 11
Outdoor Air Contaminants . . . . . . . . . . . . . . 11
2. Types of Indoor Air Contaminants and
their Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Section III Recognition of IAQ Problems
1. Reporting IAQ Problems . . . . . . . . . . . . . . . . 18
2. Gathering Data About IAQ Problems . . . . . 19
3. Role of the Health and Safety Committee
or Health and Safety Representative . . . . . . 20
Collecting Health Conditions Data . . . . . . . 23
4. How to Use Employee Feedback . . . . . . . . . 25
Section IV Evaluation and Control of IAQ
1. Units Used for Measuring Air Contaminants . 28
Vapours and Gases . . . . . . . . . . . . . . . . . . . . 28
Dust, Fibrous Glass Dust and Particulate
Matter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Asbestos and Synthetic Viterous Fibres . . . 28
Microbes (bacteria, moulds and fungi) . . . . 28
2. Evaluation and Control of Air Contaminants . 29
Carbon Dioxide (CO2) . . . . . . . . . . . . . . . . . 29
Carbon Monoxide (CO) . . . . . . . . . . . . . . . . 33
Oxides of Nitrogen (NOx) . . . . . . . . . . . . . . 35
Ozone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Formaldehyde . . . . . . . . . . . . . . . . . . . . . . . . 36
Dusts and Fibres . . . . . . . . . . . . . . . . . . . . . . 37
Tobacco Smoke . . . . . . . . . . . . . . . . . . . . . . 38
vii
Solvents: Volatile Organic Compounds
(VOCs) . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Microbial Contaminants . . . . . . . . . . . . . . . . 41
Mould . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Asbestos . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Dust Mites . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3. Sanitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4. Housekeeping . . . . . . . . . . . . . . . . . . . . . . . . . 48
Section V Ventilation
1. Heating, Ventilation and Air-Conditioning
(HVAC) System . . . . . . . . . . . . . . . . . . . . . . . . 50
Ventilation Standards . . . . . . . . . . . . . . . . . . 51
Signs of Inadequate Ventilation . . . . . . . . . . 52
Measures of Ventilation Adequacy . . . . . . . 52
Section VI Evaluation and Control of the Indoor Environment
1. Office Noise Levels . . . . . . . . . . . . . . . . . . . . . 56
Guidelines for Noise Control . . . . . . . . . . . . 57
2. Thermal Comfort . . . . . . . . . . . . . . . . . . . . . . 58
Temperature and Humidity . . . . . . . . . . . . . 58
Humidex . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Guidelines for Temperature ad Humidity . . 60
3. Indoor Temperature Regulations and
Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4. Lighting and Vision . . . . . . . . . . . . . . . . . . . . 63
Preventing Vision Problems . . . . . . . . . . . . . 63
5. Office Ergonomics . . . . . . . . . . . . . . . . . . . . . 66
Exercises to Do in the Office . . . . . . . . . . . . 71
Section VII Instruments for Indoor Air Quality Assessment 77
Section VIII Regulations, Standards and Guidelines
1. Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
2. Standards and Guidelines . . . . . . . . . . . . . . . 84
viii
Section IX Health and Safety Legislation
1. Canadian OH&S Legislation . . . . . . . . . . . . 91
What Does the OH&S Legislation Say? . . . 92
Government鈥檚 Responsibilities . . . . . . . . . . 92
Employee Rights and Responsibilities . . . . 92
Supervisor鈥檚 Responsibilities . . . . . . . . . . . . 93
Employer鈥檚 Responsibilities . . . . . . . . . . . . . 93
Joint Health and Safety Committee (JHSC) 93
Role of the Joint H&S Committee . . . . . . . 94
Work Refusals . . . . . . . . . . . . . . . . . . . . . . . . 94
Work Stoppage . . . . . . . . . . . . . . . . . . . . . . . 95
2. Workplace Hazardous Materials Information
System (WHMIS) . . . . . . . . . . . . . . . . . . . . . . 96
3. Material Safety Data Sheets (MSDSs) . . . . . 98
4. Public Health Promotion Legislation . . . . . . 99
5. Fire Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6. Building Code . . . . . . . . . . . . . . . . . . . . . . . . 100
7. Environmental Protection Legislation . . . . 100
8. US OH&S Legislation . . . . . . . . . . . . . . . . . 101
Section X Information Sources
1. Canadian Government Departments
Responsible for Occupational Health
and Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
2. US Federal Safety and Health Agencies . . 110
3. State Occupational Health and
Safety Plans . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Appendix A1 Sample Health Survey . . . . . . . . . . . . . . . . . . . . . 122
Appendix A2 Ventilation System Inspection . . . . . . . . . . . . . . 127
Appendix A3 Selecting and IAQ Consultant . . . . . . . . . . . . . . . 136
ix
2. Types of Indoor Air Contaminants
and their Sources
In order to control indoor air contaminants we must
identify their origin. It isn't always possible to pinpoint a
single source. The following table gives some examples
of indoor air contaminants and their potential sources.
Sample
SPECIFIC INDOOR AIR CONTAMINANTS
AND THEIR SOURCES
Contaminant: Asbestos
Source: Certain old fireproofing and thermal
insulation materials, ventilation
shafts and ducts, boilers
Contaminant: Ammonia
Source: Blueprint machines, cleaning compounds,
detergents
Contaminant: Benzene, toluene, petroleum solvents
Source: Rubber cement, copier toner, liquid
eraser cleaning solvents, certain
paints and coatings
Contaminant: Diethylethanolamine
Source: Boiler water additive
Contaminant: Methyl alcohol
Source: Spirit duplicating machines
Contaminant: Trichloroethylene
Source: Some correcting fluids, inks, adhesives,
cleaning compounds
鈻?
13
2. Gathering Data About IAQ
Problems
Establish IAQ problem reporting procedures in
consultation with the health and safety committee.
A report should include the following information:
Sample
IAQ PROBLEM REPORTING FORM
Date
Work area (floor/department/location)
Symptoms experienced by individuals
鉂? am 鉂? pm
Time of day symptoms are experienced
Frequency and duration of symptoms
History of symptoms (When were they first noticed?)
Building conditions that may be related to indoor air quality problems
(renovation, new equipment, etc.)
Work activities and processes that may release air contaminants
Suggested remedial actions
Encourage people to report any health complaints and unacceptable
workplace conditions. Air quality is suspect if people frequently
experience dry throat; eye and throat irritation, headache,
drowsiness, and/or general malaise. Typically people experience
these symptoms when they have been working in the building for
several hours, and feel better after leaving the building.
19
4. Housekeeping
MINIMIZE accumulation of loose and dust-producing
materials and waste.
PLACE all trash and scrap in proper containers.
DISPOSE of oily rags in covered metal containers.
CLEAN UP spills promptly following prescribed
procedures.
CLEAN UP moulds and dirt patches on walls and windows.
CLEAN soaked carpeting professionally within 24 hours to
prevent mould and bacteria growth in the fibres,
backing and under the carpeting.
Bleach
Glass
Cleaner
Cleans
er
DO NOT BLOW OFF dust. Use a vacuum cleaner or
brush.
48
WEAR clothing appropriate for office conditions.
ENSURE that ventilation systems, dehumidifiers and
humidifiers are properly cleaned and maintained.
INSULATE hot and cold surfaces.
DO NOT USE heaters that produce toxic fumes
(e.g., kerosene heaters).
DO NOT INSTALL partitions and room dividers without
evaluating the impact on local ventilation and
ensuring proper provision of supply air and air
circulation.
American Society of Heating, Refrigeration and Air
Conditioning Engineers, (ASHRAE) Standard 55-1992
is generally used as a guideline for thermal environment.
Office Space with Partition Dividers
61
Microbial Organism Air sampling to determine colony Fungal spores, microbial Requires specific
Sampling forming units per cubic meter. organisms. expertise in microbial
Spores are collected and allowed Rank order assessment. sampling for IAQ.
to grow on some type of agar Colony forming units per
medium cubic meter (CFU).
Dust Monitor
IN OUT
PPM LASER DUS
T MONITOR
PULSE PUM
P
200 MANUAL
10MIN
0.1
5
1
2
POWER
BATT
C-ADJ START
X 10
/STOP
MODE FLO
W
HIGH
CO2 Sample
LOW
Time
Temp Constant
ON
Humidity Statistics
OFF
CO Print
Sampling temperature
Mode
off
Clear
Memory velocity
Logging
Interval
hold
ON/OFF
change
ted in USA
ANDLE
of breathing passages without
respiratory
protection. MOKE C
Handle carefully . Protec Air Sampling Pump
place. tection
tory pro
a cool dry
INUTE S Thermo
t respira
Store in
es withou Anemometer
plosive passag
THREE-M SIXTY-SECOND
Non-ex athing
on of breSMOKE CANDLE
se irritati
can cau lly
Smoke Non-explosive
CAU Store in a cool dry place.
TION: Handle carefu Calorimetric Tubes
Multi-purpose Monitor
Thermoanemometer
81
Smoke Candles/Tubes
WHMIS SYMBOLS AND CLASSES
Contents under high pressure.
CLASS A
Cylinder may explode or
Compressed Gas
burst when heated, dropped
or damaged.
May catch fire when exposed
CLASS B
to heat, spark or flame. May
Flammable and
Combustible Material burst into flames.
May cause fire or explosion
CLASS C
when in contact with wood,
Oxidizing Material
fuels and other combustible
material.
Poisonous substance. A single
CLASS D, Division 1
exposure may be fatal or
Poisonous and
cause serious or permanent
Infectious Material:
damage to health.
immediate and
serious toxic effects
Poisonous substance. May
CLASS D, Division 2
cause irritation. Repeated
Poisonous and
exposure may cause cancer,
Infectious Material:
birth defects, or other
other toxic effects
permanent damage.
May cause disease or serious
CLASS D, Division 3
illness. Drastic exposures may
Poisonous and
result in death.
Infectious Material:
biohazardous
infectious material
Can cause burns to eyes, skin
CLASS E
or respiratory system.
Corrosive Material
CLASS F May react violently causing
Dangerously explosion, fire or release of
Reactive Material toxic gases, when exposed
to light, heat, vibration or
extreme temperatures.
97
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