Biocides

All new and reviewed biocidal products intended for notification must undergo a rigorous risk assessment to examine the potential risks posed to humans and the environment. This assessment should follow the framework set out in Regulation (EC) 1488/94, and implemented in the detailed Technical Guidance Documents on Risk Assessment for New and Existing Substances..

Exposure assessments for biocidal products present a unique set of challenges and need to be assembled with great care. The diversity of potential usage scenarios and routes of entry into the environment imply that a wide range of exposure assessment techniques may be required.

Environmental Emission Scenario Documents (ESDs) provide a tool to estimate the quantities of active substances that may be released into the environment during the lifecycle of a biocidal product. The Emission Scenario Documents provide a relatively simplistic approach to exposure assessment based upon product use scenarios and realistic worst case default assumptions of product loadings and transport processes. CEA experts are familiar with the range of available ESDs and are able to incorporate these product-specific approaches into the more generalised exposure estimation frameworks provided in the Technical Guidance Document

Several ESDs have been developed through previous EU funded projects (EUBEES 1 and EUBEES 2) or OECD activities. However, for some product types an ESD remains to be developed. Furthermore, the existing ESDs are necessarily rather generic, and do not account for the wide variety of specific application scenarios (and potential exposure pathways) that might occur within a particular product group. Consequently, in some situations it may be necessary to develop specific emission scenarios, incorporating principles outlined in the ESDs that are available for similar products. CEA has considerable expertise in developing bespoke, innovative, and scientifically valid approaches to risk assessments for biocides. Furthermore, the risk assessment team has extensive experience of communication with regulators (rapporteurs) regarding the development of robust exposure scenarios.

CEA have taken an active role in OECD Expert Groups contributing projects to develop Emission Scenario Documents for Product Type 18. These include:

  • Emission Scenario Document for Insecticides for Stables and Manure Storage Systems (http://ecb.jrc.it/biocides/)
  • Emission Scenario Document for Insecticides, acaricides and products to control other arthropods for household and professional uses (ongoing)

In the former project, CEA contributed a chapter to the document outlining potential refinement options. We have also played a key role in co-ordinating input from industry into the development of these ESDs via our involvement in CEFIC working groups.

CEA are also part of the expert group for the OECD project to develop ESDs for the following product types:

  1. Disinfectants used in private and public health areas
  2. Veterinary hygiene biocidal products
  3. Disinfectants used in food and feed areas

Where the initial exposure assessments suggest exposure and risk is unacceptable, more sophisticated modelling can be carried out to refine the risk assessment. For example, where additional information is available, and the scientific validity of such an approach can be demonstrated, the default values incorporated in the assessment may be refined to generate more realistic Predicted Environmental Concentrations (PECs). This refinement may be achieved through:

  • Better definition of usage;
  • Better estimates of exposure concentrations and exposure potential;
  • Better understanding of effects on non-target organisms.

Such an increased understanding of these aspects may be achieved through:

  • Usage surveys;
  • Literature data;
  • Dossier evaluation;
  • Interrogation of existing data;
  • Additional Data.

CEA experts are skilled in utilising such information in order to provide a better understanding and estimate of risk. This will allow the generation of a more refined risk assessment where the degree of uncertainty surrounding that risk is reduced to an acceptable level.

CEA is also experienced in the use of modelling tools for biocide risk assessment including multi-compartmental models such as EUSES and USES. In addition, more specific modelling approaches may be used to refine estimates of fate in particular environmental compartments such as sewage treatment plants (e.g. SimpleTreat), soil (e.g. FOCUS suite of models, LeachP) and surface water (e.g. EXAMS and TOXSWA).