Made from BPA/BPS free non leaching polypropylene with a BPA /BPS free silicone seal and air valve. This material is more brittle than other plastics. Please take care when using with very young children, or toddlers who may chew the spout.
The caps have a small air valve and care must be taken not to lose this valve when cleaning the caps and please instruct small children not to remove the valve. The new valve is tricky to remove but if you are concerned please do not use for very small children. Cap operation video YouTube
