California Green Building Code (CALGreen) – IAQ testing

The practice’s that guarantee healthy air quality at the conclusion of construction and to offer a testing option to building flush-out. It outlines test procedures, permitted pollution levels, and requirements for repeat testing. Testing can be more expensive than building flush-out, but it should be noted that due to CALGreen’s requirements for low VOC-emitting materials, pollutant levels from finishes may be low.

CALGreen Code Section A5.504.2.1: IAQ testing.

If a designer determines that building flush- out pursuant to Section A5.504.2 is not feasible, a testing alternative may be employed after all interior finishes have been installed, using testing protocols recognized by the United States Environmental Protection Agency (U.S. EPA).

CALGreen Code Section A5.504.2.1.1: Maximum levels of contaminants.

Allowable levels of contaminant concentrations measured by testing shall not exceed the following:

1. Carbon Monoxide (CO): 9 parts per million, not to exceed outdoor levels by 2 parts per million;

2. Formaldehyde: 27 parts per billion;

3. Particulates (PM10): 50 micrograms per cubic meter;

4. 4-Phenylcyclohexene (4-PCH), if fabrics and carpets with styrene butadiene rubber (SBR) latex backing, are installed: 6.5 micrograms per cubic meter; and

5. Total Volatile Organic Compounds (TVOC): 300 micro- grams per cubic meter.

CALGreen Code Section A5.504.2.1.2: Test protocols.

Testing of indoor air quality should include the following elements:

1. The contaminant sampling and averaging times and the measurement methods should be sufficient to achieve a Limit of Detection that is below the maximum allowable concentrations.

2. Testing should be conducted with the HVAC system operated at the minimum design outdoor air ventilation rate.

3. Air samplers and monitors should be located near likely sources of formaldehyde and other volatile organic compounds, at a height of 3 to 6 feet from the floor, and well away from walls and air diffusers.

4. The test protocols should be justified with documentation to show that appropriate sampling methods and times were used.

CALGreen Code Section A5.504.2.1.3: Noncomplying building areas.

For each sampling area of the building exceeding the maximum concentrations specified in Section A5.504.2.1.1, flush out with outside air and retest samples taken from the same area. Repeat the procedures until testing demonstrates compliance.

Note: U.S. EPA-recognized testing protocols may be found on the Air Resources Board website.


The intent of this measure is to provide a testing alternative to building flush-out, and promote practices to ensure healthy air quality at the close of construction. It spells out test protocols, allowable levels of pollutants and retesting requirements. Testing can be a greater cost than building flush-out, but it is noted that, with CALGreen’s requirements for low VOC-emitting materials, pollutant levels from finishes may be low; thus testing could target only those areas of potential problems, if building flush-out is determined by the designer to be infeasible. The California Energy Code also contains ventilation standards for conditioned spaces. CCR, Title 8, contains additional regulations for worker safety.

Compliance Method:

Designers should include the requirements for testing of pollutant levels of air and materials in the project specifications for ventilation, as applicable. Materials to be tested and test methods and protocols should be included. As determined in the contract for construction, testing laboratory or other qualified personnel should be engaged to conduct IAQ tests according to protocols. If test results show excessive concentrations, retesting should be carried out until compliance is achieved. Test methods and results should be made available to the enforcement agency.


Plan intake: The plan reviewer should review the plans and specifications for the designer’s testing alternative to building flush-out.

On-site enforcement: The inspector should verify if testing is to be employed on the project and ask for documentation of test methods and results at the conclusion of the process.

(Excerpted from ‘Guide to the 2022 California Green Building Standards Code Nonresidential’ – Appendix A5)

You May Also Like