Silica was identified as a workplace hazard identified by the Occupational Safety and Health Administration (OSHA). OSHA created guidelines to protect workers, especially in the construction industries, from exposure to respirable crystalline silica.
Silica is the basic component of sand and rock. It’s in construction materials such as:
When very small (respirable) silica dust particles are inhaled they can penetrate deep into the lungs causing a disease called silicosis. Silicosis is a disabling, irreversible, and sometimes fatal lung disease for which there is no cure. Since silicosis affects lung function, it makes you susceptible to lung infections such as tuberculosis. For smokers, this is more hazardous, as smoking damages the lungs and adds to the damage caused by breathing silica dust. The other bad news is that crystalline silica is also a known carcinogen which means it can cause lung cancer.
However, even with appropriate measures to control silica, some workers may still be affected. For this reason, periodic medical examinations are important for determining if the control measures in place are effective and if workers are suffering from any of the effects of silica exposure. This is known as medical surveillance and can be considered to be a method of early detection and prevention of silicosis.
Engineering controls are methods of designing or modifying equipment, ventilation systems, and processes to minimize the amount of a substance that gets into the workplace air. They include substitution, process control, ventilation and enclosure.
Personal protective equipment includes protective clothing and respirators. The purpose of protective clothing is to prevent the contamination of regular clothing and the transportation of silica-containing materials from the workplace. Clothing that is contaminated with silica dust should not, therefore, be worn home without cleaning.
Sometimes engineering controls and work practices cannot lower the concentration of silica to non-hazardous levels and workers must wear respirators for protection. If respirators must be used, a respirator program should be implemented. It should include written procedures for the selection, use, care, and maintenance of personal respiratory protection equipment. Workers should be instructed and trained on the care and use of personal protective equipment before using it. Some workers may have a medical condition that causes them to have difficulty breathing when wearing a respirator. Such workers should not be assigned to do work that requires a respirator if they have written medical proof of their condition.
The following general use, care, and maintenance procedures should be followed whenever respirators are required:
Ideally, respirators should be assigned for the exclusive use of one worker. But before a decision is made for a respirator to be shared by more than one worker, the following factors should be considered:
Respirators with a tight-fitting facepiece must be fitted to the worker in such a way that there is an effective seal between the equipment and the worker’s face. Each worker must be fit-tested for each type of respirator to be worn.
Training is an important component in preventing worker exposure to silica. Control methods, measures and procedures can only be as effective as the workers carrying them out. It is therefore essential for training to cover the following:
Instruction and training should be provided by a competent person. This could be the employer or someone hired by the employer. A competent person is defined under the OHSA as a person who:
The health and safety representative or the representative of a joint health and safety committee should be advised about when and where the training and instruction are to be carried out.