How to perform application specific Environmental Risk Assessment (ERA)

A general finding from many risk assessment studies is that chronic eco-toxicity data are often lacking. The assessment factors (safety factors applied in order not to underestimate the risk) for the Predicted No-Effect Concentration (PNEC) are therefore high. Essential physico-chemical properties, such as figures for biodegradation or the octanol-water partition coefficient (K_ow)  are also often lacking and this results in difficulties in modeling the environmental distribution of the chemical. The QSAR (Quantifiable Structure Activity Relationship) models for calculating the K_ow are not reliable for surface active chemicals, which makes it even harder to model these kind of chemicals.

In the kind of initial risk assessment that is described here many assumptions, hypothesis and worst case scenarios are discussed and analyzed. This is OK in an initial assessment, but it may be hard to know whether the assumptions or choices would be accepted in a review of a full risk assessment. In the European chemical Substances Information System (ESIS) many chemical risk assessments can be downloaded and answers of how to approach the chemical modeling may be found in these.

To learn about modeling the distribution of chemicals in the environment it may be educational not to use a software tool, but to calculate it "by hand", using the Technical Guidance Document (TGD) as guidance. EUSES (European Union System for the Evaluation of Substances) is a useful tool, but in order to know what happens "behind the interface" the equations and default figures have to be known.
 

Business value
Performing environmental risk assessments within a company is most often a requirement from authorities for registering a chemical product for a specific use or in order to get a production permit for a specific site.

Knowing whether the product may cause detrimental effects in the environment, in the short as well as the long term, helps in avoiding unwanted surprises later on. ERA is one tool that can help in determining this, because possible risks are clearly presented for all of the life cycle steps, from the production to the end use and the waste handling. ERA studies can also assist in deciding if toxicity tests and/or exposure measurements are useful or necessary to perform, which makes it easier to plan the needed resources.

A risk assessment will probably be required in the safety report of the new chemicals policy, REACH, and ERA will thereby be an important tool in the future registration and authorization process of chemicals.
Having the competence within the company for making these environmental risk assessments reduces the costs for external consultants and makes it easier to discuss arising environmental issues with the authorities. Using the strategy early in the product development process may also be beneficial in that possible environmental effects from using the product can be foreseen and risk management measures implemented earlier.