If dispersant application is deemed a suitable response technique based upon an appropriate assessment of the situation, including potential impacts and known information such as oil type, weather conditions, etc., it is recommended that a basic field dispersant effectiveness test be carried out to ensure dispersant suitability prior to applying dispersant on a large-scale, using either vessels or aircraft. If the field dispersant effectiveness test appears to suggest the dispersant is potentially effective, then a small test spray should be conducted, which will allow a small control area to be treated, monitored and assessed. Once these tests have been conducted and based on the results, then additional assets could potentially be deployed.

If dispersant application (including test spraying) is considered as a potentially suitable response technique, OPRED must be directly consulted for advice, with non-objection obtained from OPRED prior to any dispersant application undertaken.

OSRL can provide large-scale dispersant application with the use of the Boeing 727 Aerial Dispersant Aircraft. This aircraft is currently based in Doncaster Sheffield Airport (UK), and has the Tersus Spray System permanently installed.