How Fit-for-Purpose Product Stewardship Reduces Vulnerabilities
May 27, 2020

When placing a product on the market, it is essential to understand the potential environmental impacts of its chemical constituents so that unnecessary risks can be avoided or mitigated. What are the hazards associated with the product? How is the product used and what are the associated human and ecological exposures? Are there significant risks that must be addressed?

Product stewardship involves answering these questions before a product enters commerce—ensuring that the product’s ingredients are studied and evaluated for their potential risk. When questions on environmental impacts are not answered, confusion can ensue, and “stories” that result from misinformation may fill the gap. If you, as a product manufacturer, don’t tell your product’s safety story, others may tell it for you, sometimes in an unbecoming manner. Fit-for-purpose product stewardship reduces these kinds of vulnerabilities by providing you with answers.

Environmental Risk Assessment

The risk assessment process involves several phases, and while there tends to be a lot of emphasis placed on the analysis phase (hazard identification, dose-response assessment, exposure assessment, and risk characterization), the problem formulation and scoping phases are equally important. Effectively defining the problem allows the appropriate level of effort to be applied.

Why Tiered Environmental Risk Assessment?

Figure 1. Conceptual Model for Tiered Risk Assessment

Using a tiered approach focuses resources where they are most needed. Lower tiers (shown as step 1 in Figure 1) use conservative assumptions to screen out negligible risks, often at a lesser cost. Similarly, increasing sophistication in the assessment process can be applied as circumstances dictate, moving towards more detailed modeling and more realistic assumptions. These higher tiers often have a higher cost, as shown in pink. Figure 1 illustrates the benefits of tiered risk assessment. (The blue area shows that we can’t expect a realistic assessment from limited data, while red shows us that we needn’t generate a complex data set when a simple conservative approach will do.)

The assessment process is implemented in an iterative fashion such that an initial conservative assessment that doesn’t yield sufficient confidence in the outcome would not necessarily lead to a conclusion that a product is unfit for sale. One would simply move to the next higher level of analysis and revisit the decision of whether to move forward with commercialization. However, the business consequences of additional analysis (i.e., greater cost and time to commercialization) would have to be incorporated into the decision-making process.

The framework for the tiered environmental risk assessment is illustrated below in Figure 2. This framework includes tiers for environmental exposure data (shown as item 2) and tiers of ecotoxicological hazard data (shown as item 3). There are tools available to scale the risk assessment to fit any situation and resource capability.

Figure 2. Tiered Environmental Risk Assessment Framework (adapted from the HESI Risk21 program; Embry et al. 2014)[1]

Case Study in Tiered Environmental Risk Assessment

When an Integral client needed a program to annually assess the potential environmental impacts of the hundreds of ingredients in its products sold across five continents, we used a tiered approach across the entire portfolio of chemicals, products, and geographies.

Application of Tier 1 and Tier 2 screenings showed that 93 percent of the ingredients in the chemical portfolio are low priority for additional hazard assessments or refined exposure characterizations because predicted environmental concentrations were below conservative screening thresholds, in this case, a preestablished ecological threshold of toxicological concern (ecoTTC).

Figure 3. Outcome of Tiered Exposure Evaluation of Ingredients

Meeting Stewardship Goals Efficiently and Effectively

Our work using tiered environmental risk assessment helped our client meet its product stewardship goals efficiently and effectively, ensure product safety, and document its practices across numerous product lines marketed around the globe at an appropriate level of effort for its organization. The most intensive assessment effort was reserved for those 31 constituents that showed the highest potential for emissions and hazards. Moreover, the approach developed allowed the client to rapidly reassess its portfolio as its products and markets evolved over time.

Integral continues to help clients bring new products to market, and determine the safety of existing products, using innovative approaches that fit their organizational needs and abilities.

For more information on a tiered and exposure driven approach to environmental risk assessment, contact Paul DeLeo at

[1] Embry, M.R., A.N. Bachman, D.R. Bell, A.R. Boobis, S.M. Cohen, M. Dellarco, I.C. Dewhurst, N.G. Doerrer, R.N. Hines, A. Moretto, et al. 2014. Risk assessment in the 21st century: Roadmap and matrix. Critical Reviews in Toxicology 44:6-16. Available at: