White or greenish (chrysotile), Blue (crocidolite),
or gray-green (amosite) fibrous, odorless solids; freezing/
melting point5600 C (Decomposes). Hazard
identification (based on NFPA-704 M Rating System):
Health 2; flammability 0; reactivity 0. Insoluble in water.
Asbestos is a generic term that applies to a number of naturally
occurring, hydrated mineral silicates incombustible in
air and separable into filaments. The most widely used in
industry in the United States is chrysotile, a fibrous form of
serpentine. Other types include amosite, crocidolite, tremolite,
anthophyllite, and actinolite.
Habit: prismatic crystals, columnar to fibrous even asbestiform.
Color: clove-brown
to dark brown.
Diaphaneity: translucent to nearly opaque.
Luster: vitreous to silky.
Fracture: subconchoidal.
Cleavage: perfect [210].
Streak: colorless.
Others: infusible
and insoluble in HCl.
Occurrence: metamorphic rocks.
Anthophyllite is a common component of metamorphic and metasomatic rocks, composed of a Magnesium iron silicate hydroxide.
Confirmed carcinogen
with experimental tumorigenic data.
Mutation data reported.
Most asbestos is used in the construction
industry. Much of it is firmly bonded, i.e., the asbestos
is “locked in” in such products as floor tiles, asbestos
cements, and roofing felts, and shingles; while the remaining
8% is friable or in powder forms present in insulation
materials, asbestos cement powders, and acoustical products.
As expected, these latter materials generate more airborne
fibers than the firmly bonded products. The asbestos
used in nonconstruction industries is utilized in such products
as textiles; friction material including brake linings
and clutch facings; paper, paints, plastics, roof coatings;
floor tiles, and miscellaneous other products. Significant
quantities of asbestos fibers appear in rivers and streams
draining from areas where asbestos-rock outcroppings are
found. Some of these outcroppings are being mined.
Asbestos fibers have been found in a number of drinking
water supplies, but the health implications of ingesting
asbestos are not fully documented. Emissions of asbestos
fibers into water and air are known to result from mining
and processing of some minerals. Exposure to asbestos
fibers may occur throughout urban environments perhaps
resulting from asbestos from brake linings and the flaking
of sprayed asbestos insulation material. In recent years,
much effort has been put into removal of asbestos insulation,
particularly from schools and other public buildings
where worn or exposed asbestos causes public exposure.
Incompatibilities: None
UN2212 Blue asbestos (Crocidolite) or Brown
asbestos (amosite, mysorite), Hazard class: 9; Labels:
9-Miscellaneous hazardous material. UN2590 White asbestos
(chrysotile, actinolite, anthophyllite, tremolite), Hazard
class: 9; Labels: 9-Miscellaneous hazardous material.
Asbestos may be recovered
from waste asbestos slurries as an alternative to disposal.
Landfilling is an option for disposal if carefully
controlled.
