OSHA and Silica Control

Recently OSHA published a 72 paged guide on controlling silica exposures on construction worksites.  This guide breaks down several aspects of dust control, from the best control measures to housekeeping tasks that stir up dust.  Though tips were laid out for each task, there were a few common themes echoed in each situation.

• In every task, wet methods, such as wet cutting, wet grinding, manual spraying, and freezing are considered the most effective in each area.  The idea is that by wetting dust; it becomes too heavy to achieve the airborne state that can cause life threatening injuries.
• Vacuum Dust Collection systems or VDCs were next on the list.  Although the jury is still out on this method.  The guide described two conflicting studies on VDC systems.  Still for certain task, such as using a handheld saw OSHA gave tips on what to look for in the a good VDC kit.
• Ventilation Booths were also mentioned, but not as emphasized as the other methods. As OSHA acknowledged that you would need to play around with the different elements of your booth to achieve maximum protection.
• It is unanimous, that using a fan as a primary method for controlling dust is ineffective method.  Although, it can be used as a supplement to another more primary.

OSHA also noted that simpler things, such as employee repositioning or using a smaller grinder wheel can aid in controlling dust.  The guide goes further to stress the importance of distinguishing the difference between visible dusts versus the respiratory dust; stating that visible dust should not be a gauge of how well silica and respiratory dust is being controlled.

Although specific tasks such as using handsaws, jackhammers, and similar tools were detailed, OSHA detailed the various common construction duties or “housekeeping,” activities could easily stir up dust at a worksite.  Please note that this is not a complete list, but dust can become airborne due to things such as:

• Dry sweeping
• Dumping bags of raw material
• Emptying vacuums
• Using blowers or compressed air for cleaning
• Driving over debris

The guide focused on controlling silica exposure by reducing the dust in a construction worksite.  Yet, OSHA acknowledged the fact that some employees and some jobs will require the use of respirators.  Employers need to be providing either half-piece or full-faced NIOSH approved respirators that are properly fit for specific employees; or, disposable respirators that are designed with an N, R. or P 95 filter.  On worksites where respirators are required or used, a written respiratory protection program should be implemented.

For more information the guide is available for print at the OSHA website, www.OSHA.gov

References:

Controlling Silica Exposures in Construction; http://www.osha.gov/Publications/3362silica-exposures.pdf; Accessed September 23, 2009.