Occupational Safety and Health Administration
U.S. Department of Labor
Health Hazard Information Card
- What is crystalline silica (quartz)?
The term "crystalline silica" and "quartz" refer to the same thing.
Crystalline silica is a natural constituent of the earth's crust and is a
basic component of sand and granite.
- What is silicosis?
Silicosis is a disease of the lungs due to the breathing of dust containing
crystalline silica particles. This dust can cause fibrosis or scar tissue
formations in the lungs that reduce the lung's ability to work to extract
oxygen from the air. There is no cure for this disease, thus, prevention is
the only answer.
- What are the symptoms of silicosis?
There are several stages of silicosis. Early stages may go completely
unnoticed. Continued exposure may result in the exposed person noticing a
shortness of breath upon exercising, possible fever and occasionally bluish
skin at the ear lobes or lips. Silicosis makes a person more susceptible to
infectious diseases of the lungs like tuberculosis. Progression of the disease
leads to fatigue, extreme shortness of breath, loss of appetite, pain in the
chest, and respiratory failure, which all may lead eventually to death. Acute
silicosis may develop after short periods of exposure. Chronic silicosis
usually occurs after 10 or more years of exposure to lower levels of quartz.
- Where are general industry employees exposed to crystalline silica dust?
The most severe exposures to crystalline silica result from sandblasting,
which may be done to clean sand and irregularities from foundry castings,
finish tombstones, etch or frost glass, or remove paint, oils, rust, or dirt
from objects that will be repainted or treated. Other exposures to dust from
sand occur in cement manufacturing, asphalt pavement manufacturing, and the
foundry industry. Crystalline silica is used in the electronics industry and
in manufacturing abrasives, paints, soaps, and glass. Calcined diatomaceous
earth, which can contain crystalline silica, is used for filtration in food
and beverage production.
- How is OSHA addressing exposure to crystalline silica-containing dust?
OSHA has established a Permissible Exposure Limit, or PEL, which is the
maximum amount of airborne crystalline silica that an employee maybe exposed
to during the work-shift. OSHA is also beginning a Special Emphasis Program to
inform employers and employees about the occurrence and hazards of crystalline
silica and ways to reduce exposure to the dust.
- What can employees do to limit their exposure to crystalline silica?
- Employers are required to provide and assure the use of appropriate
controls for crystalline silica-containing dust. Be sure to use all
available engineering controls such as blasting cabinets, water sprays, and
local exhaust ventilation. Substitution of less hazardous materials can also be
used.
- Be aware of the health effects of crystalline silica and that smoking
adds to the damage.
- Know the work operations where exposure to crystalline silica may occur.
- Participate in any air monitoring or training programs offered by the
employer.
- Use type CE positive pressure abrasive blasting respirators for
sandblasting.
- For other operations where respirators maybe required, wear a respirator
approved for protection against crystalline silica-containing dust. Do not
alter the respirator in any way. Workers who use tight-fitting respirators
cannot have beards/mustaches which interfere with the respirator seal to the
face.
- If possible, change into disposable or washable work clothes at the
worksite; shower and change into clean clothing before
leaving the worksite.
- Do no eat, drink, use tobacco products, or apply cosmetics in areas
where there is dust containing crystalline silica.
- Wash hands and face before eating, drinking, smoking, or applying
cosmetics outside of the exposure area.
If you have any questions about any occupational health
matter, feel free to ask us. Our job is to protect your health. For more
information, contact your local or Regional OSHA office (listed in the telephone
directory under United State Government - Department of Labor - Occupational
Safety and Health Administration).
|