The preservative debate has been running for two decades. Parabens were the first to face public scrutiny following a 2004 study detecting them in breast tissue. The study did not establish causation, but the reputational damage was done.
Phenoxyethanol emerged as the alternative of choice — broadly effective, globally approved, and free from the paraben stigma. But at concentrations above 1%, it can cause skin irritation and is restricted for use in products for children under 3 in the EU.
The HumanSafe approach: evaluate each preservative at its actual concentration in the finished product, against the specific exposure pathway (leave-on vs rinse-off), and for the specific user profile. A preservative scoring B in isolation may score A in a rinse-off formulation at 0.5%.