Understating OSHA’s Respirable Silica Table 1

As we discussed in our post last week the silica standard OSHA 1926.1153 is in effect and everyone is talking about it.  Having had the opportunity to discuss the standard with OSHA hygienists we wanted to share what we thought was some helpful information.  Since the measurement of airborne silica is a fairly involved process OSHA has provided us with Table 1 which provides the Specified Exposure Control Methods When Working With Materials Containing Crystalline Silica.  This table can save you a lot of time and costly monitoring and provides you with the answers on what to do when working with materials containing silica.

When you should use Table 1

Table 1 identifies control measures for the eighteen most common activities that deal with materials containing silica.  Tasks such as cutting, grinding, drilling and chipping are all covered in Table 1.  The table is broken down into 3 parts, the task, engineering and work practice controls and respiratory requirements.  

Task: This column describes the activity that is being performed that is working with materials containing crystalline silica.

Controls: This column describes the engineering and work practices controls that must be put in place.  Often times this includes items such as utilizing integrated water delivery systems in tools or integrated vacuums.

Respiratory: This column is actually broken into two columns.  Exposure over 4 hours and under 4 hours per shift.  Here they identify if a respirator is required and if so what type.

When reading this table the hygienist recommended by determining first how long the worker would be exposed to the task.  This would be critical information necessary once you have put in place the required engineering and work process controls are in place.  The duration also often determines if any respirator would be needed based on what task would be performed.  Once you have put in place the necessary respirator, if any, and the engineering controls you are considered to be compliant with the standard.  This table is extremely helpful as no additional measurement or monitoring is required of the work being performed.  OSHA worked with industry to develop this table which covers the most common activities that will contain silica.

What to do if your task is not listed in Table 1?

There are still a lot of commonly performed tasks that do not fall within Table 1 and in this case you must measure the employee’s exposure to crystalline silica.  If the measurable limit a worker is exposed to or is reasonably expected to be above the action level of 25 μg/m3 you will need to provide an action plan to either reduce exposure or provide respirators to the workers exposed.  OSHA has stated that engineering and work process controls should be our first plan of action before respirators.  In many cases we can reduce the exposure below the allowed limit by utilizing these controls.  


If you are interested in how SafeSite can help you identify, track and manage your silica plan reach out to one of our team members.

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