Canned water has real advantages over plastic bottles in a few areas, particularly recycling and shelf life, but it’s not a clear winner across the board. The answer depends on what “better” means to you: fewer chemicals leaching into your water, less environmental damage, or longer storage life. Each container has trade-offs worth understanding.
Chemical Leaching: Different Risks in Each Container
Plastic water bottles are made from PET, a type of plastic that contains antimony, a metal used during manufacturing. At room temperature, antimony levels in bottled water are low, typically ranging from 0.25 to 0.51 parts per billion. That’s well within safety limits. The problem starts with heat. When PET bottles are stored at 50°C (about 122°F, roughly the temperature inside a parked car on a hot day), antimony concentrations jump to 8.5 ppb within 24 hours, exceeding the EPA’s maximum contaminant level of 6 ppb. Leave them at that temperature for a week and levels climb to nearly 17 ppb. At 80°C, researchers have measured antimony at 18 ppb.
Freezing plastic bottles, on the other hand, doesn’t cause any significant change in antimony levels. The risk is specifically tied to heat, which is why that case of water sitting in your trunk all summer is a legitimate concern.
Aluminum cans have their own chemistry to consider. The inside of every aluminum can is coated with a thin liner to prevent the metal from reacting with the liquid. These liners historically contained BPA, a well-known endocrine disruptor. Most manufacturers have moved to alternatives like TMBPF-based epoxy coatings or acrylic resins. Whether these replacements are completely harmless is still being evaluated by food safety agencies, but the shift away from BPA is largely complete in the canned beverage industry.
One less-discussed finding: a 2023 study in the Journal of Hazardous Materials screened 162 beverage products for endocrine-disrupting chemicals, including PFAS (“forever chemicals”), bisphenols, and other contaminants. Concentrations of these chemicals were actually higher in beverages packaged in metal cans compared to glass, plastic, and carton packaging. That result may surprise people who assume cans are the “cleaner” option. The can liners appear to be a source of contamination that partially offsets the advantage of avoiding PET plastic.
Environmental Impact: Recycling Tells Part of the Story
Aluminum’s biggest selling point is recyclability. In the U.S., 43% of aluminum cans were recycled in 2023. That comfortably beats PET plastic bottles at 20% and even glass at about 40%. When you factor in imported and exported cans processed by U.S. industry, the aluminum recycling rate reaches 57%. Aluminum can also be recycled indefinitely without losing quality, while plastic degrades with each recycling cycle and often ends up downcycled into lower-grade products.
But recycling rates don’t capture the full picture. Producing a single aluminum can requires significantly more energy than producing a single PET bottle. Life cycle assessments consistently show that aluminum has a larger carbon footprint at the manufacturing stage. Mining bauxite, refining it into aluminum, and forming it into cans is an energy-intensive process. For single-use containers (buy one, drink it, recycle it), this energy cost is hard to offset even with aluminum’s superior recyclability. The environmental math shifts in aluminum’s favor mainly when recycling rates are high and the aluminum is actually recaptured, since recycling aluminum uses roughly 95% less energy than making it from raw materials.
If the can you toss ends up in a landfill, its environmental footprint is worse than the plastic bottle’s. If it gets recycled, it’s better. Your local recycling infrastructure matters more than the container itself.
Shelf Life and Storage
This is where canned water wins decisively. Aluminum cans block light and air completely, two factors that degrade water quality over time. Properly stored canned water can last 30 years or more. Plastic bottles typically have a shelf life of one to two years before the plastic begins to break down and affect taste, and heat accelerates that degradation along with chemical leaching.
For emergency preparedness or long-term storage, canned water is the clear choice. For water you’re buying at a gas station and drinking within the hour, shelf life is irrelevant.
Cost and Availability
Canned water is dramatically more expensive. A 40-pack of plastic bottled water at a big box store runs under $4. Canned water from brands marketing aluminum packaging often costs $50 or more for a 24-pack, and it’s harder to find in physical stores. Some of that markup reflects smaller production scale and branding (many canned water companies position themselves as premium or eco-conscious products), not the actual cost difference of the materials.
Canned sparkling or flavored water is more competitively priced since it competes in the seltzer market, where cans are standard. But for still water, you’re paying a steep premium for the aluminum packaging.
Which One Should You Actually Choose?
If your main concern is avoiding chemical exposure in everyday drinking water, neither container is perfect. Plastic bottles are safe at room temperature and below but become problematic with heat. Aluminum cans avoid the heat-leaching issue but may expose you to endocrine disruptors from their interior linings. Glass or a reusable stainless steel bottle filled from a filtered tap eliminates both concerns.
If your priority is environmental impact and you reliably recycle, aluminum has the edge. If you’re storing water for emergencies, canned water lasts decades longer. If cost is the deciding factor, plastic bottles are a fraction of the price. The honest answer is that switching from plastic to canned water is a modest improvement in some categories and a step backward in others, not the straightforward upgrade that marketing often implies.