Health implications of plastic packaging for mineral water: A scientific examination of potential risks associated with chemical leaching and polymer degradation

The predominant polymer utilized worldwide in the packaging of mineral water and commercial beverages is polyethylene terephthalate, designated by the resin identification code 1 enclosed in a triangle (PET). It is a thermoplastic polyester synthesized via the polycondensation of ethylene glycol and terephthalic acid. While PET bottles provide lightness, optical clarity, and robust mechanical strength, their industrial manufacture relies on heavy metal catalysts—predominantly antimony trioxide (Sb2O3)—alongside thermal stabilizers, plasticizers, and antioxidants that may persist within the polymer matrix in unbound fractions.

Storing drinking water in polymer containers inherently involves chemical migration—the diffusion of residual monomers, additives, and degradation products from the synthetic matrix into the liquid. The rate of this mass transfer is heavily dictated by environmental exposure. Elevated ambient temperatures (e.g., bottles left inside sun-baked motor vehicles), direct solar ultraviolet (UV) radiation, and prolonged shelf life are primary accelerants. Under these conditions, thermal and photochemical polymer degradation drastically accelerates the leaching of acetaldehyde, formaldehyde, antimony, and endocrine-active phthalate derivatives.

From a toxicological standpoint, the primary hazard centers on Endocrine Disrupting Chemicals (EDCs). Although pure PET resin does not incorporate Bisphenol A (BPA) as a building block, analytical assays have repeatedly identified phthalate plasticizers and xenoestrogenic contaminants with measurable affinity for human estrogen receptors. Furthermore, chronic low-dose ingestion of leached antimony poses potential risks to cardiovascular and hepatic homeostasis. An emerging critical concern is microplastic and nanoplastic particulate contamination sheared from caps and bottle walls during handling; these submicron particles can traverse the intestinal epithelial barrier and elicit localized tissue inflammation.

To mitigate dietary exposure to leached chemicals from PET packaging, consumers should implement evidence-based safety practices. Single-use PET bottles should never be refilled with liquids, exposed to heat, or washed with hot water; structural micro-fractures sharply increase additive desorption and promote bacterial biofilm proliferation. Never drink water from bottles left exposed to sunlight. The safest and most environmentally sustainable alternatives include purchasing mineral water in glass bottles, using food-grade stainless steel or borosilicate glass containers, and utilizing multi-stage domestic tap water filtration systems.

Within the European Union, food contact materials are governed by rigorous statutory standards, notably Framework Regulation (EC) No 1935/2004 and Commission Regulation (EU) No 10/2011 on plastic materials intended to contact foodstuffs. These legal frameworks establish stringent Specific Migration Limits (SML) for potential toxicants, including antimony (SML 0.04 mg/kg food) and designated phthalate esters. The European Food Safety Authority (EFSA) continuously updates toxicological safety evaluations based on modern human biomonitoring data, progressively tightening safety thresholds and promoting safe, bio-based packaging polymers.