There is a risk that gel-filled teethers may burst when the baby is chewing on them, causing the baby to swallow the gel. This could be cause for concern as some gels may contain parabens.
A 2019 study found that, although the levels of preservatives and parabens found in gel-filled teethers were not alarming, it would be preferable for them to avoid using preservatives and parabens. It also found that there is no legal restriction on using parabens in gel-filled baby teethers.
People should avoid gel-filled teethers for babies.