Green Public Procurement (GPP) means that public authorities seek to procure goods, services and works with a reduced environmental impact throughout their life-cycle compared to goods, services and works with the same primary function that would otherwise be procured.
Sustainable Public Procurement (SPP) means that public authorities seek to achieve the appropriate balance between the three pillars of sustainable development - economic, social and environmental - when procuring goods, services or works at all stages of the project.
Many public authorities in the EU are implementing GPP as part of a broader approach to sustainability in their purchasing which also addresses the economic and social aspects.
The current Procurement Directives allow for the inclusion of social requirements in contract performance clauses and the reservation of certain contracts for performance by sheltered workshops or employment programmes (Articles 26 and 19 of Directive 2004/18/EC respectively).The inclusion of social requirements at other stages of the procurement process are addressed in Buying Social: A Guide to Taking Account of Social Considerations in Public Procurement.
Further information socially responsible public procurement in the EU context is available on the website of DG Employment, Social Affairs and Inclusion.
The United Nations has developed detailed guidance on sustainable procurement for the UN system, which addresses all three aspects of sustainability: "Buying for a Better World".
Further useful information regarding SPP can be found in the "Recommendations for the Swiss Federal procurement offices"