|
WCA Environment supplies the water, chemicals, retail and regulatory sectors with independent, high quality, and objective scientific advice on the environmental sources and pathways of chemicals, and their effects on human and ecological receptors. WCA Environment has extensive expertise in environmental risk assessment.
At WCA we have undertaken risk assessments and chemical safety assessments on individual chemicals such as 4-tert-pentylphenol (CAS no. 80-46-6 - see report), groups of chemicals such as Heavy Oils and different physical forms of chemicals, such as nanomaterials (see report).
Furthermore, we have experience of assessing human health and environmental risks associated with the recycling of organic materials to land. We have also developed a number of tools for the rapid assessment of ecological risks which incorporate a contemporary understanding of contaminant availability and bioavailability. 
The assessment of chemical risks in the absence of good quality biological effects and exposure data can be extremely challenging. In such circumstances the use of modelling approaches (QSAR and related non-testing methods, i.e. chemical grouping and read-across) for setting predicted no effect concentrations (PNECs) may be appropriate. Watts and Crane Environment have examined existing approaches to PNEC derivation and how and where QSAR and other in silico methods might be used to improve the validity of PNECs where there is a shortage of data for all the required and appropriate endpoints. We have produced client reports on substances for which there is clearly potential for use of QSAR or read-across approaches. Uncertainty in the use of non-testing estimation methods is most important when these estimates produce the lowest NOEC or EC50 (i.e., lower than any available test data). Under such circumstances use of a higher assessment factor might be appropriate. In contrast, if non-test estimated values fall within the range of test values it may be appropriate to use standard assessment factors and assume that the estimates are of similar quality to test values.
- Our risk assessment experience goes beyond just national UK assessments. Staff at WCA Environment have considerable experience in the environmental risk assessment of organic chemicals and trace metals and have been closely involved in Existing Substances Regulations (793/93/EEC) risk assessments for the UK Competent Authority, including provision of advice at TCNES (Technical Committee on New and Existing Chemicals).
|
