Key Terms

Abrasive blasting is a process for cleaning metal and other surfaces. This is accomplished using material in a high-pressure stream. The material is forced against a surface to remove paint or contaminants. If silica sand is used as the material, then this process is called sandblasting.

Accelerated silicosis develops 5 to 10 years after exposure to high concentrations of crystalline silica.

Action level indicates the amount of a harmful or toxic substance requiring medical surveillance, increased industrial hygiene monitoring, or biological monitoring.

Acute silicosis symptoms can develop a few weeks to 5 years after exposure to very high concentrations of crystalline silica. The term "acute" usually refers to a short but severe illness. In acute silicosis, the time between exposure and severe illness is shorter than is found in accelerated or chronic silicosis.

Air monitoring is the use of specialized equipment to measure different types of pollutants and their concentrations in the atmosphere.

Biopsy involves removing and examining tissue, cells, or fluids from a living body for diagnosis of disease.

Chronic silicosis develops after 10 or more years of exposure to low concentrations of crystalline silica.

Crystalline silica is a mineral made of silicon and oxygen (SiO2) that is naturally abundant in the earth's crust. In its crystalline form - primarily as quartz, tridymite, or cristobalite - silica may be harmful if inhaled. It is safe to humans unless it is inhaled.

Cyanosis is a bluish or purplish discoloration due to inadequate oxygen concentration in the blood. This discoloration is most often seen in the skin, but it occurs in other body systems. Patients who suffer from silicosis often also present with cyanosis due to breathing problems.

Engineering controls are methods for controlling worker exposures to hazardous agent. Controls adjust the source or reduce the amount of the hazardous agent that is released in the workplace. Examples include a change in process, substitution of less harmful job activities or materials, isolation of the substance, and ventilation. Engineering controls are the preferred method for targeting worksite hazards.

Fibrosis is the scarring of the lungs, often due to breathing harmful dusts or chemicals such as crystalline silica. As the disease develops, the lungs stiffen and become less flexible, which makes breathing increasingly difficult.

Fit testing is the process of checking to see that a respirator fits properly and does not allow pollutants to be inhaled.

Local exhaust ventilation (LEV) is an air movement system for capturing pollutants in the air. It captures the pollutants directly where they are produced and carries them away before they can spread throughout the work area.

Respirable particles are airborne particles within a size range that allows them to be inhaled. These particles penetrate deeply into the lungs.

A respirator is a device worn over the mouth, nose, or entire head to protect the user from inhaling harmful agents.

Safety data sheets (SDSs) - formerly referred to as Material Safety Data Sheets, or MSDSs - are written summaries of important safety and health information about a chemical or substance. Manufacturers must supply an SDS for each hazardous agent when purchased. Employers must make an SDS available to employees for each hazardous agent they use or are exposed to.

Sandblasting is the process of cleaning metal and other surfaces using sand in a high-pressure air stream. The sand is forced against a surface to remove paint or contaminants. This process is also called abrasive blasting.

Silicosis is a type of nodular fibrosis of the lungs and shortness of breath caused by prolonged inhalation of silica-containing dust.

Substitution is the removal of a harmful agent from a process and its subsequent replacement with an agent that is less harmful to health.

Wet methods involve the use of water or other suitable liquids with industrial processes, such as cutting, sanding, and grinding, to reduce dust concentrations in the air.

Work practices are the procedures followed by employers and workers to control hazards in the workplace, for example, use of wet methods to control dust.

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