This Executive Webinar introduces the goals and procedures for contaminated site assessment (CSA) relating to oil and gas activities, identifying and describing the properties and weathering of oil in different environments, the types and sources of contamination, potential impacts to the environment and socio-economic setting from contamination by oil of the soil, freshwater, polar and marine environments.Country examples including from oil contaminated site assessments undertaken in Iraq will be presented. The Executive Webinar is organized by UN Environment, who works in partnership with the Government of Norway’s Oil for Development Programme. While the long-term goal of the UN Environment is to reduce the world’s reliance on fossil fuels to fight climate change, we also recognize that oil and gas will remain part of the global energy mix in the foreseeable future. Therefore, UN Environment’s work in this sector is to ensure that oil and gas are produced in an environmentally and socially acceptable manner and do not impact negatively on local communities.