A new randomized controlled trial reveals that limiting plastic touchpoints in food storage and preparation can slash your exposure to harmful chemicals in just one week. Researchers from the Plastic Exposure Reduction Transforms Health (PERTH) Trial found that participants who switched to plastic-free kitchenware and sourced food from producers minimizing plastic contact showed significant reductions in urinary levels of bisphenol A (BPA), a chemical that interferes with hormones, and phthalates, plasticizers used to make plastic flexible.

What Chemicals Are Leaching From Your Food Storage?

Most people don't realize that the containers storing their food are actively releasing chemicals into meals. Phthalates, primarily used to make plastic flexible, migrate into food during processing, handling, transportation, storage, and packaging. Bisphenol A (BPA), found in polycarbonate containers and epoxy resin coatings inside metal cans, leaches into food especially when containers are heated or used repeatedly. These aren't trace amounts either. The PERTH Trial tracked 211 Australian adults and found that highly processed, plastic-packaged, and canned foods were major contributors to elevated urinary levels of plastic-associated chemicals (PACs) in the body.

Why does this matter? Both phthalates and BPA are endocrine-disrupting chemicals, meaning they interfere with your body's hormone systems. Epidemiological studies have linked exposure to these chemicals with cardiovascular disease, metabolic syndrome, elevated cholesterol, and insulin resistance. The health effects are thought to occur through inflammation and changes in how your body processes lipids, the building blocks of cell membranes and hormones.

How Much Can You Reduce Your Exposure in Just 7 Days?

The PERTH Trial's pilot randomized controlled trial tested 60 participants across four intervention groups. Some received plastic-free kitchenware, others received low-plastic personal care products, and some received food sourced from over 100 producers that minimized all plastic touchpoints from farm to plate. The results were striking:

• Bisphenol A (BPA): Urinary levels dropped by 59.7% in the intervention group, with over 95% certainty this reduction was real and not due to chance.
• Monobenzyl phthalate: Levels decreased by 53.5%, a reduction significant enough to suggest meaningful health protection.
• Mono-n-butyl phthalate: This phthalate metabolite fell by 37.5%, demonstrating that even shorter-chain phthalates respond to reduced plastic exposure.

Importantly, the intervention maintained participants' daily energy intake while decreasing plastic exposure. This wasn't about eating less; it was about eating the same amount from sources with minimal plastic contact. The most dramatic reductions occurred in groups that received foods with minimal to no plastic contact, suggesting that food packaging is the primary pathway for these chemicals entering the body.

Why Glass and Borosilicate Containers Offer Superior Protection

If plastic containers are the problem, what's the solution? Borosilicate glass stands out as a chemically inert alternative that never leaches harmful compounds into food. Unlike plastic, borosilicate glass is made from stable, naturally occurring materials: silica, boron trioxide, soda ash, and alumina. Once fused at high temperatures, these materials form a structure free of BPA, phthalates, lead, and cadmium. The pharmaceutical industry uses borosilicate glass, classified as USP/EP Type I glass, for injectable drug packaging, where any chemical migration into the contents would be medically unacceptable. If it meets that standard, kitchen use is straightforward.

Borosilicate glass also resists thermal shock better than standard glass or plastic alternatives. Its coefficient of thermal expansion, the rate at which a material expands or contracts with temperature changes, is roughly one-third that of ordinary soda-lime glass. This means borosilicate can survive temperature differentials of around 330 degrees Fahrenheit before fracturing, compared to just 100 degrees Fahrenheit for standard glass. In practical terms, you can move a borosilicate dish directly from the refrigerator to a hot oven without risk of cracking or shattering.

Non-stick coatings present their own chemical concern. Research published in Science of The Total Environment found that degraded non-stick coatings can shed up to 2,300,000 microplastics into food. Borosilicate glass avoids this problem entirely while also distributing heat more evenly than metal cookware, reducing scorching and hot spots that can char food edges.

How to Transition Away From Plastic Food Storage

• Replace plastic food containers: Swap plastic storage containers, lunch boxes, and food wraps with borosilicate glass alternatives. Glass containers won't leach chemicals into leftovers, acidic foods like tomato sauce, or oily dishes.
• Choose glass for cooking and baking: Use borosilicate glass bakeware and cookware instead of plastic cutting boards, plastic utensils, or non-stick pans that may shed microplastics or harmful coatings.
• Source food with minimal plastic contact: When shopping, prioritize foods packaged in glass, paper, or cardboard rather than plastic. The PERTH Trial found that foods sourced from producers minimizing plastic touchpoints from production through packaging had the broadest effect on reducing chemical exposure.
• Avoid canned foods when possible: Metal cans are lined with epoxy resin coatings that contain BPA. Fresh or frozen foods in glass or paper packaging are safer alternatives.
• Switch personal care products: The PERTH Trial found that replacing plastic-packaged personal care products with low-plastic alternatives independently decreased urinary mono-n-butyl phthalate levels, showing that exposure pathways extend beyond food storage.

The Bigger Picture: Why One Week Matters

The speed of these chemical reductions is remarkable. Phthalates and bisphenols have short half-lives in the body, meaning they're rapidly cleared through urine. Yet few randomized controlled trials have tested whether modifying everyday exposure pathways can effectively lower urinary levels of these chemicals. The PERTH Trial addressed this gap by being the first to minimize all plastic touchpoints during food production, handling, processing, packaging, storage, and preparation, while also addressing non-dietary sources like personal care products.

Earlier dietary intervention studies showed inconsistent results, often because they focused only on plastic-free packaging of the final food product or targeted single-food replacements. The PERTH Trial's comprehensive approach, addressing plastic exposure across the entire food system from paddock to plate, proved far more effective. This suggests that small changes in one area of your kitchen may help, but comprehensive plastic reduction delivers the most dramatic health benefits.

The research also found negative associations between higher urinary levels of di(2-ethylhexyl) phthalate (DEHP), a common plasticizer, and cardiometabolic biomarkers, meaning people with higher phthalate exposure showed worse markers for heart and metabolic health. This connection strengthens the case for reducing plastic contact with food as a preventive health measure.

While regulatory agencies in several countries have limited exposure to specific chemicals like DEHP and BPA, manufacturers often simply substitute them with structurally similar chemicals like di-iso-nonyl phthalate (DNP) and bisphenol S (BPS), which have comparable health concerns but less regulatory scrutiny. This regulatory whack-a-mole underscores why reducing plastic exposure broadly, rather than relying on chemical-by-chemical regulations, may be the most effective personal health strategy.