Disclaimer: Although this information product reflects housing experts'
current knowledge, it is provided for general information purposes
only. Any reliance or action taken based on the information, materials
and techniques described are the responsibility of the user. Readers
are advised to consult appropriate professional resources to
determine what is safe and suitable in their particular case. DASH
Inspection Services assumes no responsibility for any consequence
arising from use of the information, materials and techniques
Always, always consult with a Qualified Licensed Professional.
What is asbestos?
Asbestos is a natural mineral with unusual qualities. It is strong enough
to resist high temperatures, chemical attack and wear. A poor conductor,
it insulates well against heat and electricity.
Asbestos crystals become long, flexible, silky fibres, so it can be made
into a wide variety of forms. It can be spun into yarn, woven into cloth or
braided into rope. Asbestos can also be added to materials as diverse
as cotton and cement.
This combination of properties gives asbestos performance capabilities
that are difficult to match.
What has asbestos been used for?
Asbestos has been used in hundreds of applications and products over
the past 4,500 years. The ancient Greeks wove it into oil lamp wicks,
funeral shrouds and ceremonial tablecloths. During the 1800s, it
insulated the hot engines, boilers and piping that powered the Industrial
For half a century, until the 1980s, asbestos was used in office
buildings, public buildings and schools. It insulated hot water heating
systems, and was put into walls and ceilings as insulation against fire
Asbestos has also been widely used in transportation and electrical
appliances, frequently mixed with, and encased in, other materials.
Asbestos has also been found in many products around the house. It
has been used in clapboard; shingles and felt for roofing; exterior siding;
pipe and boiler covering; compounds and cement, such as caulk, putty,
roof patching, furnace cement and driveway coating; wallboard; textured
and latex paints; acoustical ceiling tiles and plaster; vinyl floor tiles;
appliance wiring; hair dryers; irons and ironing board pads; flame-
resistant aprons and electric blankets; and clay pottery. Loose-fill
vermiculite insulation, typically found in Attics. may contain traces
of “amphibole” asbestos.
How has the use of asbestos changed?
When it became evident that regular exposure to asbestos on the job
involved health risks, the public became more concerned about
exposure to asbestos in offices and schools, and, eventually, about all
This concern has led to a dramatic decline in asbestos use since the
early 1980s. The use of asbestos insulation in buildings and heating
systems has virtually disappeared. Residential use, for roofing, flooring
and appliances, continues to decrease.
While alternative products are being developed to replace asbestos,
products sold today containing asbestos are regulated under the
Hazardous Products Act. Asbestos can be used safely, and public
concern has led to improved product design and manufacture. Asbestos
is now better encapsulated and sealed to reduce the escape of fibres.
Asbestos is valuable in many applications because it has been difficult to
find comparable substitute materials. For example, it is still an important
component of brake lining and clutch facings.
What health problems are associated with exposure to asbestos?
Health Canada states that the asbestos content of a product does not
indicate its health risk.
Asbestos poses health risks only when fibres are in the air that people
breathe. Asbestos fibres lodge in the lungs, causing scarring that can
ultimately lead to severely impaired lung function (asbestosis) and
cancers of the lungs or lung cavity.
Concern for the health of asbestos workers was expressed as long ago
as the late 1800s. The risks became more evident in the late 1960s,
when workers who had been heavily exposed 20 to 30 years earlier
showed increased incidence of lung disease. Occupational exposure is
now strictly regulated by provincial governments.
When can asbestos be a problem in the home?
Today, far fewer products in the home contain asbestos. Current
products that do contain the material are better made to withstand wear
However, frequent or prolonged exposure to asbestos fibres may still
bring health risks. This can happen with the release of fibres into the air
when asbestos-containing products break down, either through
deterioration as they age or when they are cut. People can put
themselves at risk — often without realizing it — if they do not take
proper precautions when repairs or renovations disturb
asbestoscontaining materials. This can occur in a number of situations:
Disturbing loose-fill vermiculite insulation which may contain asbestos
Removing deteriorating roofing shingles and siding containing asbestos,
or tampering with roofing felt that contains asbestos
Ripping away old asbestos insulation from around a hot water tank
Sanding or scraping vinyl asbestos floor tiles
Breaking apart acoustical ceilings tiles containing asbestos
Sanding plaster containing asbestos, or sanding or disturbing acoustical
plaster that gives ceilings and walls a soft, textured look
Sanding or scraping older water-based asbestos coatings such as
roofing compounds, spackling, sealants, paint, putty, caulking or drywall
Sawing, drilling or smoothing rough edges of new or old asbestos
How to minimize the asbestos risks in the home?
If you do not know if products in your home contain asbestos, have an
experienced contractor inspect them. If there is asbestos, the best
interim measure (unless the product is peeling or deteriorating) is to seal
the surface temporarily so that fibres will not be released into indoor air.
If the product is already protected or isolated, simply leave it alone.
It is a complex and expensive matter to remove asbestos, and should be
done by an experienced contractor. When disturbing an asbestos
product, maximum precautions must be taken to safeguard the workers
and anybody else who may be nearby. Asbestos dust must remain within
the work area so that it cannot be breathed in by unprotected persons.
It is essential to take adequate precautions. Everybody who works with
asbestos should always wear an approved face mask and gloves, along
with protective clothing. Be sure to tape sleeve and trouser cuffs, and
wash clothes separately after use. Keep the work area moist to keep
dust and fibre particles from floating into the air. Isolate the work space.
Reduce the air pressure to prevent asbestos fibres from escaping from
the work area, and filter the exhaust air. Dispose of all waste
appropriately, according to the guidelines of your provincial department
of the environment. Other removal methods may be warranted for
special conditions — consult an expert.
Testing for Asbestos in Vermiculite
Vermiculite insulation in loose form can be readily visually identified as a
light weight, silvery grey or blonde, granular, layered material, with
particle sizes of about 2 to 10 millimeters. If vermiculite is known to have
been installed prior to 1990, visual identification should be adequate to
confirm the material as asbestos-suspect.
The visual identification can be confirmed by laboratory testing, although
caution in selecting the laboratory is advised. The laboratory should be
accredited by one of
the two US agencies that qualify laboratories for the analysis of asbestos
in bulk samples. Even these laboratories require extra care to detect the
very fine fibres at these low concentrations. Laboratories that do not
specialize in asbestos analysis should never be relied on for asbestos
It is extremely important to note that the overall percentages of asbestos
in the bulk vermiculite are very low, possibly below existing legal limits for
asbestos. None-the-less, the airborne concentrations can be very high
when the material is disturbed, due to the very fine and loose nature of
the asbestos. A recent US EPA study of six homes in Vermont showed
elevated airborne asbestos concentrations even in cases where the
laboratory could not detect asbestos in the bulk material. Therefore EPA
recommends that all loose-fill insulation visually identified as vermiculite,
and installed prior to 1990, be treated with asbestos precautions.
Some vermiculite may contain asbestos.
Do not disturb loose-fill vermiculite insulation.
Do not store items near vermiculite insulation, if the insulation can be
Do not allow children near loose fill vermiculite insulation.
If activities are planned that will disturb vermiculite, consult a certified
asbestos removal company.
The information above was taken from CMHC website and