For people who work with asphalt everyday, this may be a obvious statement: Silica is in asphalt.

There are two areas where this might be of concern:


  1. During the mixing of the asphalt there is usually some ratio of rocks that are added to the product. The size of these rocks is where safety personnel should have concerns. If they are adding the smallest fraction of rock to the mix, you may have airborne exposures to silica. This size of rock is called P200 (or, using a 200 sieve screen to get anything less than 200 parts per inch). Usually this is seen during the transfer of rock from the loader or from the belt conveyor.
  2. The other method of exposure to silica in asphalt is if you cut it. Rocks may contain silica. When asphalt is cut, you incidentally cut through various rocks (contained within the asphalt). Silica (and dust) is released during the cutting. Please use water when you are cutting asphalt. Direct the water at the blade.