Exposure Limit
Aliases: Acceptable Level Occupational Exposure Limit (OEL) TLV-TWAAn exposure limit is a maximum allowed airborne concentration for a substance that no worker is to be exposed above it. Section 2.1.1 of the HSRC establishes exposure limits for mines in B.C. The exposure limit for respirable crystalline silica (including quartz) is a Threshold Limit Value – Time Weighed Average (TLV-TWA) of 0.05 mg/m3. TLV-TWA means the time weighed average concentration for a normal 8-hour day and a 40-hour workweek, to which nearly all workers can be repeatedly exposed without adverse effect.
For exposure to a silica process longer than eight hours a day, the exposure limit is adjusted dependent on the number of hours.
Information & FAQ's
How does work activity duration affect estimated dust exposure level?
The Silica Control ToolTM estimates the average level of RCS exposure over the entire silica process.