When did you last change your water bottles?

We cyclists are obsessive about our gear. Chains and cassettes get replaced regularly, tyres are inspected for the minutest cuts, and kit is upgraded on the mere promise of aero gains.

But water bottles? They can hang around for years.

If your cupboard is anything like mine, there’s a fair chance you’ve got one from an event you rode ages ago, another that came free with something, and one so scratched by its bottle cage that the original logo has almost disappeared –  something Wanderers, I think it says.

Perhaps it’s time for a clear-out 🤔

What happens to old plastic bottles?

Researchers at the University of Copenhagen looked at what happens when drinking water is left in reusable plastic sports bottles. They tested new bottles, used bottles and bottles that had been through a dishwasher.

The findings were a little, shall we say, unsettling.

More than 400 plastic-related compounds were detected in the water. Significantly more substances appeared after bottles had been through a dishwasher. The researchers also found that dishwashing appeared to increase the release of some chemicals from the plastic itself.

So, should we be worried?

Let’s not be alarmist. This doesn’t necessarily mean our old bidons are poisoning us. Many of the substances were found only in tiny quantities, and detecting a chemical is not the same as proving it causes harm. That said, the toxicity of at least 70% of the substances was said to be ‘unknown’.

The research does, however, show that plastic bottles change with use and washing. This is worth thinking about when you consider what our bidons go through.

They’re repeatedly squeezed, scratched by bottle cages, exposed to the sun, occasionally abandoned in hot cars and, in my household at least, regularly put through the dishwasher.

When is it time to replace them?

There isn’t a scientifically agreed point at which a bottle becomes unsafe. Common sense is probably the best guide.

If yours are badly scratched, permanently discoloured, smell odd after washing, have become brittle or have simply been around for years, replacing them seems a sensible precaution.

For the ones you  keep, wash them regularly, rinse them thoroughly and allow them to dry properly. It’s also worth checking the manufacturer’s cleaning instructions. Some cycling bottles are dishwasher-safe, while others are better washed by hand (note to self).

Fancy a clear-out?

Alex Steer recommends the Elite Fly Tex — a very light, BPA-free bottle that can be completely dismantled for cleaning and drying.

They’re still plastic, of course, so don’t sidestep all the issues, but Alex says they’re good and not particularly expensive if you decide you’re now going to replace your bottles more often.