In January 2017 California Department of Public Health published version “Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources using Environmental Chambers Version 1.2”.This new version superseded the former version “Standard Practice for the Testing of Volatile Organic Emissions Using Small-Scale Environmental Chambers 1.1.”
According to the new version the benezen limit value has been reduced from 30 µg/m3 to 1,5 µg/m3. Starting April 2017 the new limit value is effective.
Further infos you find on the site of California Department of Public Health