I think the civil burden of proof should apply here. Upon the preponderance of the evidence. Given so many studies that exhaustively show correlative effects of phthalates with metabolic and endocrine disruption, especially strongly during developmental stages, I think even that burden of proof is met.
Sure, you can't prove something doesn't exist, but you can make a reasonable determination that given exhaustive study, given correlative negative effects can be ascribed to no other known cause, and given that this is natal and pediatric health especially at stake, we should say until such time as a causative link is proven to lie elsewhere these chemicals should not be used in consumer goods out of an abundance of caution.
The redirection of that claim would be "these profits are more important than moving to protect bodily health especially for those unable to protect themselves, given what we currently know."
Honestly, no knowledge is perfect, but upon the balance we must rest our sacrosanct right to health.
https://en.wikipedia.org/wiki/Modus_tollens