How dangerous is it to be exposed to silica dust?
The health effects of long term exposure to respirable crystalline silica are well documented and include silicosis, chronic obstructive pulmonary disorder (COPD) and lung cancer. The level of risk depends on the amount of exposure which is determined mainly by the materials and work methods used, the duration of the work and the controls in place.
Are there exposure limits?
Yes, the HSE published workplace exposure limits for respirable crystalline silica are very low at 0.1 mg/m3 (8-hour time weighted average).
What materials is silica in?
Quartz, the principal form of silica, is the second most common mineral in the earth’s crust. It is found in both sedimentary & igneous rocks. Quartz content varies among different rock types; for example, granite can contain anywhere from ten to forty percent quartz; shales have been found to average 22% quartz and sandstones can average 70% quartz.
In industry it is found in many of the materials used in the construction industry e.g. concrete, mortar and sandstone.
What occupations are most often exposed to silica?
There are many different occupations that may be at risk of exposure to silica, including:
• construction (sandblasting, rock/stone cutting, sawing, abrasive drilling, masonry work, chipping, grinding, hammering & tunnelling)
• glass manufacturing
• mining (cutting or drilling through sandstone & granite)
• foundry work (grinding, mouldings, shakeout, core room)
• shipbuilding (abrasive blasting)
• ceramics, clay & pottery
• brick, tile & refractory manufacture
• manufacturing & use of abrasives
How can people take precaution?
A full and appropriate risk assessment should be conducted to determine the extent of the silica exposure and should, where applicable, quantify the airborne concentration. The Health and Safety Executive publish several guidance documents for work with silica. These include the controls that should be applied, for example, water suppression when cutting kerb stones. For many situations the guidance suggests the use of respiratory protective equipment (RPE) alongside other controls. Where the use of RPE is suggested higher performing devices with assigned protection factors of 20 or 40 are specified.
Within the 3M range of RPE there are many choices of products with APFs of 20 or 40, for example:
• 3M™ Aura™ 9332+, FFP3 NR D, APF = 20
• 3M™ 8833, FFP3 R D, APF = 20
• 3M™ 8835, FFP3 R D, APF = 20
• 3M™ 7500 series half masks with 6035 P3 R filters, APF = 20
Powered air respirators
• 3M™ Versaflo™ TR-300 turbo with M-106 visor, APF = 20
• 3M™ Versaflo™ TR-300 turbo the M-306 helmet, APF = 40
Note: Wearers of all the disposable and reusable respirators above should be fit tested.
How can people find out more information?
You can always give me a call on the 3M Health & Safety helpline on 0870 60 800 60 (UK) 1 800 320 500 (Ireland) and I will be happy to help answer any questions you may have.
Our website is a great source of product related data. It can be viewed via the following link:
We also have a Silica Dust Hazard Card and microsite where you can access more information related to respirator fit testing:
The HSE website is also a mine of useful information:
To check out our webinars visit 3M Safety Spotlight