Nevenfuncties van Rob Maas, senior scientific advisor bij het RIVM.
- Chair of the UN (United Nations) Task Force on Integrated Assessment Modelling.
- Member of the Bureau of the EMEP (Europese model voor de verspreiding van lucht) Steering Body.
- Chair of the Lotos-Euros steering group (the air model of TNO, KNMI (Koninklijk Nederlands Meteorologisch Instituut), PBL (Planbureau voor de Leefomgeving) and RIVM National Institute for Public Health and the Environment ).
- Advisor of the EU (Europese Unie)-Joint Research Centre – Institute for Environmental Sustainability.
- Member of the Advisory Board of the LIAISE-Network.
- Member of the Advisory Board of ECLIPSE, FP7 (Seventh Framework Programme) research project on Black Carbon.
- Editor of the Elsevier Journal Environmental Development