Hazards - Crystalline Silica
For workers in professions such as abrasive blasting, quarrying and tunnelling, the risks of injury are clear. However, Katya Chausheva at 3M, the diversified technology company, warns that significant health hazards are also posed to the respiratory system if correct controls are not in place.
Dust is an inevitable by-product when workers chip, cut, drill or grind stone and rock and, where this dust contains crystalline silica, is proven to cause disabling illnesses and even fatalities1.
Crystalline silica is a fundamental constituent of soil, sand, granite and other minerals which, when disturbed, can break into particles capable of being inhaled. When this happens, the silica dust enters the lungs and causes scar tissue to form, hindering the lungs’ capacity to absorb oxygen – a condition called silicosis. Silicosis is incurable as the lungs cannot be repaired, leaving victims suffering severe shortness of breath.
Silicosis can occur in three main forms depending upon the individual’s exposure to silica, the duration of the exposure and the concentration of the silica. With chronic silicosis, caused by prolonged exposure to medium to low concentrations of silica, symptoms range from fatigue and shortness of breath to chest pain and respiratory failure. Sufferers of accelerated silicosis, caused by 5-10 years of excessive contact with respirable crystalline silica, can experience severe shortness of breath, weakness and weight loss. Acute silicosis is caused by excessive contact with exceptionally high concentrations of silica, and symptoms can present after only a few months. These include severe, disabling shortness of breath, weakness and weight loss which frequently results in death2. High concentrations of crystalline silica can be generated during abrasive sandblasting. Individuals working in the construction, masonry, glazing and foundry industries, as well as those manufacturing cement, brick, china and ceramics may also be exposed to silica.
Exposure to crystalline silica should be managed through engineering controls, typically local exhaust ventilation. Where further reduction in exposure is required respiratory protective equipment (RPE) is generally worn. When RPE is used employees must be trained properly in its fitting, use, storage and maintenance.
A range of RPE is available to help reduce the risks of crystalline silica. Specifiers can select from disposable or reusable half-face respirators, full-face respirators or powered respirators depending on the level of exposure identified through risk assessment and personal preference. Significant resources are being continually invested by the leading players in the market to deliver products which are effective, comfortable and wearable across a wide variety of applications, with the ultimate aim of ensuring workers do not adjust their PPE and render it ineffective, or even remove it altogether due to discomfort.
For more information please visit www.3M.co.uk/ohes.
OSHA Crystalline Silica Exposure Health Hazard Information
3M Technical Bulletin 'Respirable crystalline silica'