Asbestos Fact Sheet
General Information and History
Asbestos
is a common name given to a group of naturally occurring mineral fibers. The Greeks are known to have woven the fibers
into lamp wicks as early as the 5th Century B.C. Modern commercial use of asbestos began with
the industrial revolution in the late 19th Century. Asbestos has since been incorporated into a
wide variety of building products due to its abundance, low cost, strength,
flexibility and insulating qualities. Adding
asbestos to soft materials such as pipe insulation and acoustic plaster was
banned in the U.S. by the late 1970s. However, even today, asbestos can still be added to products that
encapsulate or otherwise bind the fibers such as vinyl floor tile, cement
pipe and asphalt roofing. While U.S.
production has diminished, asbestos-bearing ores are found worldwide and countries
such as Canada and Brazil remain major manufacturers and exporters of asbestos
products.
Map
of California showing principle asbestos deposits (expandable thumbnail)
Asbestos-Containing Materials in Stanford University Buildings
Asbestos-containing
materials are known to be present in many of the buildings on campus. In
some areas, asbestos has been identified in one or more of the products listed
below. Click on the product to view a representative
photo.
1. spray-applied fireproofing
2. pipe, tank & boiler insulation
3. air duct seam tape & vibration cloth
4. air & furnace duct insulation
5. gaskets, oakum & muffler insulation
6. cement pipe, flue, conduit & exhaust duct
7. corrugated & flat cement siding
8. cement pegboard & bender board
9. roofing tar, felt, mastic & shingles
10. plaster & sheetrock joint compound
11. acoustic ceiling or wall tile & adhesives
12. floor tile, sheet vinyl, linoleum & adhesives
13. basecove & ceramic tile adhesives
14. lab counter tops, equipment insulation & fume hood liners
15. door & wire insulation
16. caulking & glazing compounds
Health Risks
Asbestos
is only a hazard when small particles become airborne, are inhaled and deposited
within the lungs. Increased incidence of several illnesses including asbestosis, a
debilitating lung disease, lung cancer and mesothelioma, a rare cancer of
the lung or stomach cavity lining, have been observed in individuals who were
persistently exposed to high levels of airborne asbestos in work environments
such as mining, milling, shipbuilding, construction and manufacturing. Asbestos-containing materials in buildings
pose no risk to health unless asbestos fibers become airborne and are inhaled.
Intact, sealed and undisturbed materials are not a hazard.
Construction products in good condition will not release asbestos particles into the air. Hard products such as vinyl floor tile and cement shingles contain binders that completely encapsulate the asbestos for added protection. Asbestos in soft products such as pipe insulation may be completely sealed within a canvas or steel jacket. Walls, ceilings and floors may also act as barriers that separate occupied building areas from asbestos products found in mechanical rooms, crawlspaces and attics.
Protective Measures - General
EH&S
is involved in an on-going effort to survey and identify asbestos-containing
materials in the nearly 800 buildings on campus. If these materials are to
be disturbed through demolition, building repair or abatement, specific
safeguards (photos), must be followed
to prevent exposure. Signs
and labels (photos) are also used to demarcate
asbestos products and abatement activities.
All renovation or demolition of campus buildings must be reviewed in advance by EH&S. If survey information is not available, EH&S will conduct a survey and designate acceptable safe work practices for abating asbestos-containing materials. Work that requires removal or repair of asbestos-containing material or the testing of suspect material is restricted to trained and certified individuals working under the direct supervision of EH&S.
Protective Measures - Individuals