A recent post on stainless steel cookware revealed when to avoid cooking with stainless steel and when it might be acceptable for some people. The post was based on studies that showed that stainless steel cookware leached nickel and chromium into acidic food that was cooked for a long period of time. But what about stainless steel water bottles? Are they safe to use or do they leach heavy metals into water and other beverages that are not highly acidic?
Stainless Steel Does Not Leach into Plain Water
One study looked at a number of beverages with different PH levels and found that chromium and nickel did leach into beverages with high acidity such as fruit juice. It also leached into a solution with high alkalinity. However, there was no detected leaching into distilled water, which has a PH of 7 and is considered neutral because it is neither acidic nor alkaline. It also did not leach into beverages with low acidity such as tea (PH of 6.65), coffee (PH of 6.50) and milk (PH of 6.88). Tap water was not tested in this study but the EPA recommends that municipal drinking water have a PH level from 6.5 to 8.5. Based on the result of this study, it is unlikely that tap water would cause leaching.
Does This Mean I Can Keep My Stainless Steel Water Bottles?
The choice to drink out of stainless steel is a personal one. Individuals with nickel sensitivity may choose to avoid any contact with stainless steel. Also, this is the only study found that looks specifically at water and other low-acid beverages. Further studies would be beneficial.
Glass bottles are a safe alternative however, they are prone to breaking and are often heavy. If you do choose to keep your stainless steel bottles make sure they do not have the following features:
Sealing dot or painted markings
Read more about how one blogger detected lead from the sealing dot, which is a dimple at the bottom of some bottles, and from paint or painted markings on the bottles.
Plastic lids that are not BPA or BPS free
In my opinion, plastic lids are of greater concern than the stainless steel bottles because hormone disrupting chemicals can leach from all types of plastics depending on the additives used. Unfortunately, there are no safer alternatives that provide the functionality and convenience of a plastic lid, particularly if used for sports or other outdoor activities.
Low-grade stainless steel
Look for #304 or 18/8 food-grade stainless steel.