Toxicological research into the development of risk assessment procedures to enable formulation changes in approved oil treatment products to be processed as part of the FEPA approval scheme (DISCON)

Abstract:

This document is an executive summary for this project. The full report is not generally available due to prior agreements with manufacturers.

The UK statutory approval scheme for oil spill treatment products has been in place for nearly 30 years. During this time the approval process, including the two toxicity testing elements (The Sea and Rocky Shore tests), has become established as one of the most respected and comprehensive in the world. However, it has changed very little in that time and this has prompted a current review of the testing and approval process.

The review will encompass many aspects of the schemes applicability, organisation and flexibility and this research project was commissioned to address one specific aspect that had been highlighted as of particular concern. Due to the longevity of the scheme, and the fact that products require their approvals to be renewed every five years, certain products have now been through the renewal process on numerous occasions. This introduced a phenomenon known as 'constituent creep' by which small amendments by applicants were made to constituent recipes thus resulting in a slightly different formulation over time.

Scientific judgement was used to assess whether these small changes were environmentally significant but it was recognised that there was a lack of sound toxicological information regarding dispersants and their constituents to aid this decision process and therefore the advice was potentially subject to challenge. This research project was commissioned to address the issue. Extensive testing was conducted using original and amended formulations (in which specific constituent proportions were changed) to see whether modest formulation changes were toxicologically significant. In general, it was found that small changes in any constituent did not change the dispersant performance in the Sea Test but that there was some evidence of changes in the Rocky Shore test. This difference was due to the masking effect of the oil toxicity in the Sea Test and it was concluded that the test was not appropriate for differentiating between these modest formulation changes.

Further studies focused on inherent toxicity assessments of original and amended dispersants using the Tisbe battagliai bioassay. These concluded that small increases in certain constituents caused an increase in formulation toxicity (e.g. sodium dioctyl sulphosuccinate - SDS) while others caused no increase or even decreased the toxicity (e.g. sorbitan monooleate - SMO). This approach allowed the categorisation of dispersant constituents in relation to their ability to contribute and amend inherent formulation toxicity.

The toxicity results are discussed in detail and their relevance to environmental scenarios and the possible use of predictive techniques such as quantitative structure activity relationships (QSAR) are also covered in the report.

Drawing on the research results four potential 'Assessment Protocol Options' have been detailed and their advantages and disadvantages discussed. A number of recommendations are made including the need to engage other stakeholders in forming a consensus way forward with the assessment process and the need for a proposed assessment process review to address a range of important issues relating to the scheme.

Publication Year:

2005

Publisher:

Department for Environment, Food & Rural Affairs

DOI:

No DOI minted

Author(s):

CEFAS