The Offshore Strategy requires the OSPAR Commission to collect annual data on the use and discharge of offshore chemicals, emissions to air, spills, and discharges of oil and radioactive substances.

To this end, the Offshore Industry Committee (OIC) collects and assesses data on the number of installations, the use and discharge of drilling fluids and cuttings, discharges of oil in produced water, chemicals used and discharged offshore, accidental spills of oil and chemicals and emissions to air. These are published in the annual OSPAR Report on Discharges, Spills and Emissions from Offshore Oil and Gas Installations. The reports also present cumulative data on discharges dating back to 1984 as well as emissions since 1992.

Polycyclic aromatic hydrocarbons and alkyl phenols are also discharged together with oil-related hazardous substances such as heavy metals, via produced water. Furthermore, weight materials used in drilling fluids can contain hazardous substances such as barite and ilmenite, both of which contain traces of heavy metals such as lead.

The OSPAR Commission has put in place a number of measures to reduce discharges from the oil and gas industry. For example, although the amount of produced water and displacement water discharged continues to increase, the total quantity of dispersed oil discharged to the sea is decreasing. Contracting Parties have made considerable effort and investment to reach the OSPAR target of a 15% reduction in the total quantity of oil in produced water discharged along with the performance standard of dispersed oil of 30mg/l as in OSPAR Recommendation 2001/1.