Why Do Assessment Tools Differ: An In-Depth Report

Julie Panko and her team examined 32 different chemical assessment tools, such as the Green Screen methodology, Walmart’s GreenWERCS model and the GoodGuide. They discovered that, taken together, the tools sometimes result in discrepancies when it comes to assessing risk. “The U.S. EPA Design for the Environment (DfE) might say a chemical is preferred, and then you run it through one of the other models, and it says avoid this chemical,” says Panko, principal health scientist at CardnoChemRisk.

One example that stuck out was citric acid. “In some of the tools that we evaluated, citric acid got a preferred score. But in other tools, it was labeled as a void, because it's a severe eye irritant,” says Panko. ““We wanted to understand why you get different answers for different tools for the same chemical.”

At Stewardship 2015, Panko will share the team’s conclusions during the deeper dive session From Critical Reviews of Hazard Assessment Tools to Building a Product Evaluation Framework: Can We Bridge the Gaps with a Super Tool?

“We want to present the findings regarding the strengths and limitations of the various chemical assessment tools that are available on the market,” says Panko. “And then really begin a conversation with the attendees regarding alternative assessments that provide a balanced consideration not only of environmental health but technical functionality and also the business needs.”

Ultimately, tools give different answers because developers built them with different values. “One of the drivers of the difference is the kind of data sources the tool is pulling from. Is the tool getting its information from various lists? Or is it a tool that uses original toxicity data,” says Panko. “Another driver of the difference is that some tools put more weight toward some of the hazard end points than others. Some tools don’t even consider some of the end points.”

It’s problematic for companies trying to decide which tools are best to use. But if you ask Panko which she recommends, she won’t have a set answer. “It depends on what your goal is because, the tools have different purposes and don't all do the same thing,” she says. “At this point, I think groups need to work with a combination of tools, because there's no super tool out there.”