Exposure to Asbestos and Refractory Ceramic Fibers (RCFs)
Asbestos is the name given to a group of naturally occurring minerals that are resistant to heat and corrosion. Asbestos has been used in products, such as insulation for pipes (steam lines for example), floor tiles, building materials, and in vehicle brakes and clutches. Oil field workers are among those at elevated risk for asbestos-related diseases such as asbestosis and mesothelioma.
Asbestos is added to drilling mud, which was used in the oil industry, for decades. Since the 1960s, such asbestos drilling has occurred both onshore and offshore. Drilling mud composition contains asbestos, which has caused mud engineers to be exposed to asbestos in drilling mud.
Asbestos fibers associated with these health risks are too small to be seen with the naked eye. Breathing asbestos fibers can cause a buildup of scar-like tissue in the lungs called asbestosis and result in loss of lung function that often progresses to disability and death.
There is no "safe" level of asbestos exposure for any type of asbestos fiber. However, OSHA limits exposure to asbestos to an 8-hour time-weighted-average (TWA) of .1 fiber per cubic centimeter (.1 f/cc). Asbestos exposures as short in duration as a few days have caused mesothelioma in humans.
Where there is exposure, employers are required to further protect workers by:
- establishing regulated areas,
- instituting engineering controls to reduce the airborne levels,
- reducing exposure by using administrative controls and PPE, and
- conducting medical monitoring where legal limits and exposure times are exceeded.
Refractory Ceramic Fibers (RCFs)
Refractory Ceramic fibers are similar to asbestos fibers in size, shape, and long-term (months to years) exposure effects on humans. RCFs are amorphous synthetic fibers produced by the melting and blowing or spinning of calcined kaolin clay or a combination of alumina, silica, and other oxides. Oil and gas workers may be exposed to RCFs while installation and removal of RCF-containing insulation such as inside high-temperature furnaces.
RCFs, like asbestos, get into the body primarily by inhalation. The International Agency for Research on Cancer (IARC) and the American Conference of Governmental Industrial Hygienists (ACGIH) have classified RCFs as possibly carcinogenic to humans.
To limit exposure proper ventilation and personal protective equipment should be used to limit the 8-Hour TWA to .2 fibers per cubic centimeter (.2 f/cc). Workers who may be exposed to RCFs should also be provided with information on the health effects and safe work practices related to RCFs. For more information, see the NIOSH Publication 2006-123, Occupational Exposure to Refractory Ceramic Fibers.
Knowledge Check Choose the best answer for the question.
7-3. Refractory Ceramic Fibers (RCFs), like asbestos, get into the body primarily by _____.
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