Butler-Justice Inc. has been designing blue smoke control systems for the hot mix asphalt industry for several years. Blue smoke is actually tiny oil droplets that make-up the blue haze that is typically associated with paving as well as the production of hot mix asphalt. It's the blue haze that carries much of the characteristic asphalt odor. Air pollution control agencies are becoming more concerned with blue smoke, especially as RAP, rubberized asphalt and polymer blends are more routinely specified. These specialty mixes produce an increased amount of blue smoke. More blue smoke means a greater number or neighborhood complaints for visible emissions and odor, all of which results in more frequent inspections and higher potential for being "written up" by the air polution cops.