CASANZ operates through autonomous Branches which determine their own programs of activities, including technical meetings, seminars, workshops, conferences, training courses and so forth.

The purpose of the CASANZ Branches is to provide members within specific geographic regions of Australia & New Zealand with a program of seminars and training on regional and national air quality matters. These events are central to providing all members with on-going professional development and networking opportunities.

Branch committee participation enables members to directly participate in the organisation of these local programs and also the bi-annual international conference. Branches have the responsibility of providing feedback to the CASANZ Council and Executive on services required and emerging needs of members.

An important role of the Branches is through nomination for their annual clean air award of businesses and/or individuals making outstanding contributions to better air quality.