Experts Talk About Alternatives Assessment
Alternative assessment tools are meant to evaluate the health and environmental safety aspects of chemicals, but they vary in their conclusions. The American Chemistry Council evaluated several tools to see how they differed when comparing the same chemicals, and to understand why they didn’t come to the same conclusions.
The demonstration study involved seven chemicals with wide-ranging properties. They were subjected to the assessments for each tool following the same protocols that a contractor using a tool would follow.
After converting the scores so they’d be comparable across tools, the ACC found that for some chemicals the conclusions varied significantly. For instance, caffeine rated from ‘low’ to ‘very high.’ “How is that helpful to us,” said Ann Mason, senior director, Chemical Products & Technology Division at the American Chemistry Council.
ACC found that the data-driven tools were more harmonious in their conclusions than list-based tools, perhaps because data-driven tools have more end points. Another issue was the way tools handled data gaps. For some, gaps were treated as neutral and others treated them as contributing negatively to the overall score.
The marketplace is focused on safety and hazard information, said Mason, but ultimately it needs to push for more complete evaluations, including exposure and lifecycle assessments.
Erin Mulholland, analyst at thinkstep, talked about conducting lifecycle assessments (LCA), which quantify all the resources used and emissions across all stages of a product’s lifecycle. ISO standards offer a framework for conducting a lifecycle assessment. The first step is to ask what questions you’re trying to answer with the assessment.
Mulholland noted that you might only have data for one stage of the product’s lifecycle. To complete the assessment, you’ll need the material and energy inputs for the stages you don’t control. A consultant can help by providing a software model to fill the gaps.
LCA addresses potential environmental impacts but does not predict absolute or precise environmental impacts, said Mulholland. Also, the assessments do not say anything about the inherent hazard of the product. One of the challenges with LCAs is that the data can’t be used to assess exposure. The inventory data focuses on releases. It has no temporal dimension or concentration.
Hans Plugge, senior toxicologist at 3E Company, reminded attendees that the ultimate goal is to reduce overall environmental and health risks. That said, there are always tradeoffs. When dealing with alternative assessments, functionality is important. If you have data for one chemical, it’s pointless to replace it with a chemical for which you have no data. “It’s not like today you have a bad chemical, tomorrow you’re going to have a better one,” he said. Finding suitable alternatives can be a long-term process.
Instead, Plugge recommends looking for substitutes that are similar to the chemicals you’re worried about but not as much of a concern. If that’s not possible, then you’ll have to design something from scratch. He noted that no alternative is better, then you will have to conduct an exposure screening.