All of us are trying to be more eco-conscious as our planet reels from the current spate of pandemics, extreme weather conditions, food insecurity and conflict. Reusable water bottles have become a talisman of this concern – especially reusable plastic bottles.  

How safe is your water bottle?

Little is known about the migration of chemicals from the reusable bottles into drinking water. A recent study of the chemicals in reusable plastic bottles revealed more than 3500 dishwasher-related compounds in the bottles of which more than 400 remained after flushing the bottles with tap water. 

In addition, more than 400 plastic-related compounds were detected. The main culprits were plasticizers (chemicals added especially to rubbers and resins to impart flexibility, workability, or stretchability), and endocrine-disrupting compounds that are known to affect thyroid receptors, male fertility, haemostasis of hormones, cancer progression, glucocorticoid receptors, and the cardiovascular system – in animal and theoretical models.

Of the plastics, 150 compounds were flushed away by dishwasher use, a further 80 compounds were removed by flushing with tap water, but over 100 compounds remained even after flushing. Glass bottles fared a little better with only 184 compounds detected after washing and flushing with tap water. With repeated washing, most release occurs in the first 24 hours.

If you think metal bottles are safer, think again. Another study, of reusable bottles (aluminium, stainless steel, plastic, and silicone) showed that these bottles, especially metallic ones, release inorganic compounds (elements mainly) at variable amounts. The common elements most frequently released include aluminium calcium, potassium, magnesium and sodium. 

Of course, there are a host of other possible factors may also affect reusable plastic bottles, for example ultraviolet radiation from the sun and heat causing chemical reactions, cap composition, frequency of reuse, bottle age and so on. 

Scary? Well yes and no. There is as yet no longitudinal data on the effects of the minute doses of these compounds that are released. So far, results with regulatory limits on drinking water quality revealed no exceeding values except for aluminium. Also, if you are thinking about handwashing, there no studies on what gets leached through handwashing, though the persistence of compounds after tap rinsing gives us some clues. 

Enough to drive this blogger to drink – alcohol – at least the toxins there have been well studied.