You can require companies to do at least some due dilligence, though, to give a reasonable amount of comfort it is. "It's safe" is a falsifiable claim.
But that could change over time with further understanding. No point panicking today over something not known to be harmful. The effect size is clearly very small. If I wanted to better my health in an actually measurable way I'd be much better served by dropping alcohol and refined sugars than worrying about microplastics.
> But that could change over time with further understanding.
That's not a good excuse not to bother at all. It's an argument for periodic reassessment of common additives.