Environmental Risk Assessment (ERA) - The Approach
ERA - A Stepwise Approach
The environmental assessment is developed using a step-wise approach. The first step is the calculation of the predicted environmental concentrations. We have to address short-term exposures, such as an accidental spill, which may result in high concentrations in a river but for a relatively short period of time, and long-term exposures that are the result of down-the-drain discharge of used products by the consumer. An important part of the exposure assessment is to understand the biodegradation 
profile of the ingredient and the extent to which we expect it to be removed during wastewater treatment .
Next, the toxicity of the ingredient to certain environmental "indicator species" is assessed. For the aqueous environment, indicator species are typically a freshwater fish, a freshwater invertebrate and freshwater green algae. For sediments and soils, they are sediment dwelling organisms, earthworms and terrestrial plants. For air, the indicator species would be birds. However, for these types of ingredients the concentrations in air are usually so low that bird toxicity data are not needed for the risk assessment.
The next step is to assess the probability of adverse effects or the environmental risk given the estimated environmental concentrations and the toxicity to indicator species extrapolated to ecosystems. For high volume ingredients, the work of the environmental scientists may not stop here. P&G may decide to monitor the concentrations of these ingredients in the environment after they have been on the market for some time, to confirm the accuracy of the predicted environmental concentrations. A simple environmental risk assessment may be completed in a few weeks or months, but comprehensive environmental programs for high volume ingredients may take years to complete.
This step-wise, or tiered, approach to environmental safety and compatibility is described in more detail below:
Step 1 :
Review of Physical-Chemical Properties
Step 2 :Estimation of Environmental Exposure
Step 3 :Environmental Fate and Effects
Step 4 :Risk Assessment
Step 5 :Post-Market Environmental Monitoring
Some Key Publications
profile of the ingredient and the extent to which we expect it to be removed during wastewater treatment .Next, the toxicity of the ingredient to certain environmental "indicator species" is assessed. For the aqueous environment, indicator species are typically a freshwater fish, a freshwater invertebrate and freshwater green algae. For sediments and soils, they are sediment dwelling organisms, earthworms and terrestrial plants. For air, the indicator species would be birds. However, for these types of ingredients the concentrations in air are usually so low that bird toxicity data are not needed for the risk assessment.
The next step is to assess the probability of adverse effects or the environmental risk given the estimated environmental concentrations and the toxicity to indicator species extrapolated to ecosystems. For high volume ingredients, the work of the environmental scientists may not stop here. P&G may decide to monitor the concentrations of these ingredients in the environment after they have been on the market for some time, to confirm the accuracy of the predicted environmental concentrations. A simple environmental risk assessment may be completed in a few weeks or months, but comprehensive environmental programs for high volume ingredients may take years to complete.
This step-wise, or tiered, approach to environmental safety and compatibility is described in more detail below:
Step 1 :
Review of Physical-Chemical PropertiesStep 2 :
Estimation of Environmental ExposureStep 3 :
Environmental Fate and EffectsStep 4 :
Risk AssessmentStep 5 :
Post-Market Environmental MonitoringSome Key Publications