Background

Over recent decades, the pace of chemical innovation has significantly outpaced the scientific understanding of long-term health and environmental impacts. Historically, chemicals were adopted because they solved technical challenges and delivered performance benefits, such as durability or resistance. However, as analytical methods improve and exposure data accumulates, substances once considered safe are increasingly becoming the focus of scrutiny. This paper examines how bisphenol A (BPA), per- and polyfluoroalkyl substances (PFAS), phthalates, and microplastics transitioned from widely accepted use toward broader scientific, regulatory, market, and public concern.

The path to being considered a chemical of concern

A fundamental tension exists between hazard-based and risk-based regulatory approaches. One perspective focuses on intrinsic hazard, while another emphasises demonstrated risk after considering real-world exposure. The European Union generally prioritises a hazard-led approach, restricting chemicals with severe hazard properties. In contrast, the United States system, particularly under the 1976 Toxic Substances Control Act (TSCA), is more explicitly risk-based, with the Environmental Protection Agency (EPA) considering hazard alongside exposure potential, persistence, and production volume. Stakeholders often disagree on when early warning signs should trigger substitution, a debate shaped by technical feasibility and societal tolerance for uncertainty.

Case study 01: BPA

BPA is used in polycarbonate plastics and epoxy resins, with an estimated 1 million pounds released into the environment annually. Although its oestrogenic properties were identified in the 1930s, it remained commercially vital, with global production exceeding 6 billion pounds by 2008. Emerging research in the early 2000s challenged traditional toxicology by identifying health effects at doses previously considered safe. Public concern, particularly regarding infant exposure in baby bottles, led to “BPA-free” marketing claims that often preceded regulatory changes. This market shift occasionally resulted in regrettable substitution with bisphenol S (BPS), which was later found to have similar endocrine-disrupting activity.

Case study 02: PFAS

PFAS, known as “forever chemicals” due to their extreme stability, comprise a class of more than 16,000 synthetic compounds used since the 1940s. While internal industry research documented their persistence and biological accumulation in the 1970s, broad public awareness only grew in the late 2000s through litigation and media dramatisation. Toxicological studies have linked PFAS exposure to adverse outcomes, including elevated cholesterol and increased cancer risks. Regulation is now shifting toward class-based approaches. Lessons include treating exceptional performance and persistence as early design signals rather than waiting for absolute proof of harm.

Case study 03: Phthalates

Phthalates have been used as plasticisers since the 1950s, with the additive DEHP making up to 40% of some PVC polymers used in medical devices. Despite evidence of reproductive effects and neurobehavioural impacts from the 1970s, phthalates have lower public awareness than BPA or PFAS, likely due to their chemical complexity and the absence of a single “villain” compound. However, modern restrictions are accelerating via the EU Medical Device Regulation and California AB 2300. This case illustrates that limited public visibility does not equate to limited risk, and sustained scientific signals provide sufficient reason for a thoughtful transition to alternatives.

Case study 04: Microplastics

Microplastics are plastic particles smaller than 5 millimetres that have been detected in nearly every biological compartment. Global plastic production has surged from roughly 2 million metric tonnes in 1950 to more than 400 million metric tonnes in recent years. Public interest intensified in 2022 after microplastics were detected in human blood, with the narrative of ubiquity outpacing traditional risk assessment. The experience highlights how visible pollution and detection in the human body can drive rapid market and reputational risks even while the underlying health science is still being characterised.

Conclusion

The report identifies recurring signals that warrant closer scrutiny of a chemical: detection in the human body, evidence of biological activity, use in products that reach vulnerable populations, and similarity to already flagged chemical classes. Exceptional performance that makes a chemical commercially valuable can often mask overlooked risks related to persistence. Identifying these signals early allows organisations to innovate proactively, strengthening business resilience and avoiding regrettable substitutions while aligning with evolving consumer expectations and regulatory landscapes.

A practical framework for action

Organisations can adopt an eight-step framework to be more proactive: screening and prioritising based on warning signs; understanding exposure conditions; monitoring emerging scientific and market signals; engaging the supply chain; evaluating safer alternatives; investing in data and research; developing transition strategies; and leading through innovation. This proactive approach turns potential chemical risks into opportunities to improve products and strengthen customer trust.

Implementation

Successful implementation requires establishing executive ownership and cross-functional governance across departments. Organisations should build horizon scanning into routine decision-making and integrate stewardship checkpoints into stage-gate and portfolio reviews. Creating supply-chain visibility through chemical inventories and funding safer-alternative assessments are vital steps. By embedding these capabilities early, companies can identify emerging concerns and plan transitions before external pressures force action, effectively turning hindsight into foresight.