If a study shows a fragrance ingredient can cause “adverse effects” in a lab, why is it still considered safe for me to use in my daily products?

As a toxicologist specializing in repeated dose and reproductive health, I often encounter this concern. The answer lies in a principle established centuries ago by the father of toxicology, Paracelsus:
“All things are poison, and nothing is without poison; only the dose permits something not to be poisonous.”