About The Monitoring and Laboratory Division

This page last reviewed May 12, 2009



To provide accurate, relevant, and timely measurements of air pollutants and their precursors to support California's Air Quality Management Program for the protection of public health. 

A copy of MLD's Mission, Vision, and Accomplishments document is available in PDF format. 


  • Anticipate emerging needs
  • Improve program and operational efficiency
  • Promote expertise of staff
  • Outreach for division products and activities
  • Promote clear direction through effective communication
  • Encourage public/private and public/public partnerships


  • Commitment to provide accurate, relevant, and timely information to our clients
  • Integrity that promotes trust and open communication
  • Competence that results in effective, high-quality products
  • Pride in work that results from accountability and ownership


      Information about the ambient air monitoring that supports measuring children's exposure to air pollution in our communities. 
  • Consumer Products
      Information detailing consumer products that are tested by the consumer products laboratory. 
      Monitoring is conducted to quantify the average ambient concentrations of airborne dioxins, furans and dioxin-like polychlorinated biphenyls (PCBs) in the San Francisco Bay Area and the South Coast Air Basin over a two year period. 
      Summary of monitoring activities for ozone, nitrogen dioxide, carbon monoxide, and sulfur dioxide.  Monitoring is performed to demonstrate attainment or non-attainment of national and state ambient air quality standards. 
  • Motor Vehicle Exhaust Program
      Program supports efforts to determine the reactivity of fuel components by speciating exhaust samples.  The program provides hydrocarbon emissions data that can be compared against regulatory standard for non-methane organic gases tail-pipe emissions, and a number of ozone precursors. 
      Summary of monitoring activities for PM10, PM2.5, PM speciation, and total suspended particulates.  Monitoring is performed to demonstrate attainment or non-attainment of national and state ambient air quality standards.  Continuous methods are also used; however, not directly for attainment/non-attainment classification.
  • Pesticide Monitoring
      Ambient and application pesticide monitoring is performed by ARB at the request of the Department of Pesticide Regulation to collect exposure data. 
  • Photochemical Assessment Monitoring Stations (PAMS)
    Non-methane Organic Compounds (NMOC)
      Detailed information regarding the seasonal sampling of Non-Methane Hydrocarbon species in high ozone areas of the State.  Federal regulations require states to establish photochemical assessment monitoring stations (PAMS) as part of their State Implementation Plan monitoring networks in ozone non-attainment areas classified as serious, severe, or extreme. 
  • Quality Improvement
      Through various quality assurance testing and auditing, faulty data is minimized ensuring utmost accuracy.
  • Source Testing
      Emission testing or source testing is conducted to verify compliance with regulatory emission limits, to support development of control measures, test methods, and emissions inventory, and to evaluate the effectiveness of new control technologies.  The ARB has adopted over 45 test methods that are used to measure criteria pollutants (e.g., hydrocarbons, oxides of nitrogen, carbon monoxide, etc.) and toxic air pollutants (e.g., metals, polycyclic aromatic hydrocarbons, dioxins and furans, etc.) 
  • Toxic Air Contaminant Program
      Provides information regarding the statewide toxics monitoring network.  ARB is required by State law to identify and control toxic air contaminants.  Monitoring is conducted to assess exposure as part of the identification process, and to assess the effectiveness of controls. 
  • Vapor Recovery
      The ARB evaluates and tests new or modified vapor recovery systems for gasoline marketing operations.  These systems recover the gasoline vapors generated during storage and transfer operations.  The goal of the program is to assure that the vapor recovery systems which meet the regulations are certified expeditiously.