Study: Chemical Hazard Assessment Tools Yield Widely Different Results

Retailers and personal-care manufacturers should take context into account when using hazard assessment tools and communicating findings to the consumers they serve – let alone replacing ingredients with "greener" alternatives – as different approaches can generate widely varying outcomes, a new study suggests.

It's a familiar refrain from industry that chemical safety assessment should consider exposure risk in addition to inherent hazards, but a new pilot study indicates that hazard scores alone can vary significantly from one assessment tool to the next, with implications for how findings should be used and communicated.

Published May 4 in the journal Integrated Environmental Assessment and Management, the study examined results from use of various hazard screening tools popular in the marketplace to determine if seven selected chemicals would be scored consistently across platforms.

The comparative analysis is highly relevant at a time when consumers and public advocacy groups increasingly are calling for personal-care companies (among others) to discontinue or reduce their use of higher-hazard chemicals in favor of purported "greener" alternatives.

Retailers responding to customer demand have begun implementing programs that incorporate hazard assessment tools to identify chemicals of concern and prioritize them for phase-out, pressing brand partners to reformulate their products accordingly.

"There is a need for enhanced transparency and understanding of what each tool was designed to measure, as well as the appropriate conditions for each tool’s use," the ACC asserts.

In this environment, companies face the challenging task of having to conform to the parameters of varying proprietary retailer frameworks for hazard assessment. In the context of ingredient substitution, matters are further complicated if hazard findings differ for a given substance depending on the retailer tools or metrics employed.

Not surprisingly, the study at hand was conducted by the American Chemistry Council and member Dow Chemical Company, joined by consulting firms, including Cardno Chemrisk, working on their behalf.

Study authors zeroed in on five hazard assessment tools based on criteria such as the number of endpoints covered, transparency and peer review in categories including screening and prioritization, hazard assessment, and exposure and risk assessment, also taking into account the approach's market popularity.

The tools were selected from regulatory and nonprofit sources, namely the US EPA (Design for the Environment Alternatives Assessment) and Clean Production Action (GreenScreen), as well as private database and software development firms – UL LLC's The Wercs (GreenWERCS), Chemical Compliance Systems (GreenSuite) and SciVera LLC (SciVera Lens).

The investigators note that the tools differ in that some are purely list-based, meaning they simply compare chemicals against hazard lists from regulators and other accepted authorities, while others involve more sophisticated frameworks or high levels of expert analysis.

The chemicals chosen for analysis were caffeine, citric acid, ethylene glycol, glycolic acid, dibutyl phthalate, benziothiazolinone and 1,2,4,6,9,10-hexabromocyclododecane, which the authors say "represent both natural and man-made chemistries as well as a range of toxicological activity."

The team found that not one chemical scored the same across the five hazard screening tools; in fact, each assessed chemical received hazard characterizations ranging from "low" to "very high."

"Such discrepancies may call into question the extent to which such tools can provide stakeholders, including consumers, retailers and product manufacturers, with definitive and actionable information about chemical substances in consumer products without further analysis and contextual information," ACC says in a release.

According to the study, the inconsistent results are due to varying "value judgments" in terms of the safety endpoints considered by each hazard assessment tool and how those endpoints were weighted, as well as differing information sources used and how data gaps were treated, whether indifferently or negatively.

The findings show that "there is a need for enhanced transparency and understanding of what each tool was designed to measure, as well as the appropriate conditions for each tool’s use," the ACC says, suggesting that enhancements to the tools could be made to increase their utility.

Hazard Remains Just One Piece Of Puzzle

The trade group further emphasizes that hazard scores are just one component of risk assessment, which the scientific community increasingly accepts as a more meaningful approach to predicting chemical and product safety.

"Hazard-based screening does not consider how a chemical is actually used in a product, how much of the chemical substance exists in those uses, and whether and to what degree there is human or environmental exposure to the chemical substance through such uses. These properties of use, dose and exposure are a key component of regulatory chemical safety assessments conducted by government agencies around the world," the ACC says.

"Many strong tools and approaches exist in the marketplace, and when a stakeholder is armed with more information, he or she can make the best choice for their unique evaluation." – study co-author Kristen Hitchcock, health scientist at Cardno ChemRisk

Study co-author Pamela Spencer, scientific director at Dow Chemical, similarly notes that product safety can only be determined by considering potential ingredient hazards in conjunction with a product's use, which is not addressed in a list- or exclusively hazard-based approach.

A blog post by co-author Kristen Hitchcock, a health scientist in Cardno ChemRisk's Pittsburgh office, suggests that the study results signal a need for assessment rationale to be clearly conveyed to ensure that a suitable model is selected, and underscore the importance of transparency in describing the basis for tools' hazard scores.

She notes, "Many strong tools and approaches exist in the marketplace, and when a stakeholder is armed with more information, he or she can make the best choice for their unique evaluation."

ACC says it is conducting a follow-up study evaluating chemicals in the context of whole products and intended use, with an associated paper on the analysis under development.

Walmart Program Advances

It remains to be seen whether the study will have any bearing on retailer hazard-assessment programs.

In 2013, Walmart announced a program intended to promote transparency and reduce or eliminate chemicals of concern in consumer products sold on its store shelves, including beauty and personal-care items (Also see "Walmart Program Seeks Greener Beauty, Greater Supplier Transparency" - HBW Insight, 16 Sep, 2013.).

The mega-retailer's list of 10 high-priority chemicals still has not been publicly released, though reportedly it's slated for an unveiling later this year. In the interim, suppliers have been encouraged to begin reducing or replacing listed chemicals of concern with safer alternatives.

Walmart's hazard-assessment platform relies on the GreenWERCS system, requiring suppliers to enter product formulations into a database for comparison against various authoritative lists, which the study authors identify as the simplest mechanism being used in the marketplace (Also see "Walmart Sustainable Chemistry Policy A “Big Deal,” But Raises Questions" - HBW Insight, 17 Mar, 2014.).

In its Global Responsibility Report released April 20, Walmart says the system has provided the retailer with "an initial framework for evaluating our chemical footprint."

Walmart explains in the report that consumers increasingly are demanding insight into product content and ingredient safety, but available can be confusing. The big-box retailer's goal is to "make choices easier and more transparent for people."

"We’re working with suppliers to reformulate household cleaning, personal care, baby, pet, beauty and cosmetic products to remove, reduce and restrict the use of priority chemicals and replace them with safer alternatives," Walmart says.

According to its report, there has been a 95% reduction by weight of high-priority chemicals sold at US Walmart locations.

Suppliers unable to remove or replace priority chemicals have been asked to develop "time-bound action plans to reduce, restrict and eliminate usage as well as to engage in broad stakeholder initiatives to work toward industry-wide solutions," the mega-retailer says.

Walmart's policy pressed suppliers to disclose ingredients online for products sold in Walmart stores beginning in 2015. Starting in 2018, products on its shelves that contain priority chemicals will have to bear labeling declaring their presence (Also see "Walmart Sustainable Chemistry Policy A “Big Deal,” But Raises Questions" - HBW Insight, 17 Mar, 2014.).

In its report, Walmart says 76% of suppliers are reporting on their online disclosure practices, and 78% of those suppliers say they disclose ingredients online for all their products.

While Walmart's intent is to offer safer products on its shelves, the industry study asserts that "to date, no data exists that show a tool's reliability to provide consistent, credible screening-level hazard scores that can inform greener product selection."

Target has introduced a program similar to Walmart's that rewards vendors for replacing chemicals of concern and adopting sustainable practices. The program assigns a point scale to each product, with 50% of points based on ingredient safety per chemical-of-concern lists from the California EPA's Proposition 65 list, the European Chemicals Agency’s inventory of Substances of Very High Concern and other federal and state government sources (Also see "Target To Reward High-Scoring Personal Care Under Sustainable Standard" - HBW Insight, 4 Nov, 2013.).