Dow was sued over allegations that its insecticide chlorpyrifos is causally linked to Parkinson's disease and that the company and partners concealed supporting evidence.
The case puts product-safety controls and chemical-risk disclosures under scrutiny, raising the prospect of additional claims, regulatory action or changes in product usage.
$29.31 Dow shares are up 20.8% year to date but have dropped 7.6% in a week and 16.9% in a month as legal and reputational risks come into focus.
The lawsuit lands against a mixed valuation backdrop: the stock trades about 29.9% below the $41.88 analyst target, while cash-flow pressure remains a key risk if liabilities grow.