Crystalline Silica

The recent reports on the 'epidemic' of crystalline silica diseases likening it to asbestos with the implied message that silicosis and other associated diseases will sweep through the population causing an asbestos like quantum of deaths is disingenuous.

Rather than creating this hysteria, clear communication of the hazards, risks and controls measures is required to all businesses whose work practices disturb high crystalline silica content materials.

As early as 1934, the hazards associated with crystalline silica were known and raised by the International Labour Organisation. In 1988, NIOSH (National Institute of Occupational Health and Safety) USA, recommended that crystalline silica be considered a potential carcinogen. It is on the list/schedule, in all Australian Health and Safety Regulations, of substances that require employers to conduct health surveillance and is specifically banned for use in sand blasting. Furthermore, there are numerous publications identifying the types of materials that contain high levels of the substance.

It must be noted that the presence of crystalline silica is not the risk, it is the creation of respirable particles, generally considered less than 10um in diameter, that have the potential to penetrate deep into the lungs and cause a range of health effects.

The major quarries, concrete cutters and manufactures of products containing crystalline silica that HAZCON works with have monitoring processes in place to determine if their engineering and isolation controls are protecting their workers. These companies are aware of the risks and verifying that the processes have in place will protect their workers from inhaling the hazardous particles.

In Australia the increase in silicosis is believed to be as a result of engineered stone and granite surface preparation where the problem arises for employers who:

• Are not aware of the risks associated with crystalline silica, or
• Are aware but feel they have systems in place to protect workers, or
• Are acting irresponsibly because of cost or inconvenience to implement rigorous control measures.

Engineering Controls

Robust engineering controls validated by personal monitoring for respirable dusts including crystalline silica have to be put in place to ensure processes for products containing crystalline silica including cutting, drilling, grinding, milling or polishing the products are safe.

It is not good enough to just hand out respirators to workers as they only reduce exposure by a factor of 10-100. When airborne levels exceed 10mg/m3, which are not unknown, personnel will still be inhaling up to ten times the current Workplace Exposure Standard of 0.1mg/m3 if only supplied a P2 half face respirator. 

Using engineering controls to capture dust or significantly suppress it by using water should be the first choice in the hierarchy of controls. This is especially true for controlling the dust spreading and contaminating all the surfaces in the work environment.

Reflecting upon what has been done in the manufactured wood product industry (MDF), one can hope the suppliers of crystalline silica rich materials provide information to buyers of the risks of using the product and the controls they should be implementing. It is then beholden on the users to seek further advice from regulators, manufacturers and occupational hygienists.

Only then can we be a little more confident that the rise in crystalline related illnesses will be curtailed and ultimately be eliminated.

Ian Good