Why preservative-free cosmetics are a tough commercial product

Preservative-free cosmetics that survive in your bathroom cupboard are a challenge, says Evolu founder Kati Kasza.

However, producing a 100% natural skin cream on a commercial basis presents a challenge. The moment you add water to oil to create an emulsion you produce the perfect environment for bacteria, yeast and mould to flourish – Kasza draws a comparison with homemade mayonnaise that lasts for only a few days in the fridge.

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For a skincare product to have a long enough shelf life, particularly one that is likely to be stored in a steamy bathroom, some sort of preservative is required.

In the early days of Evolu, the broad-spectrum preservatives of choice were parabens, which are effective against mould, yeast and bacteria. But there were concerns that these might play a role in endocrine disruption.

“Once that suspicion was raised, parabens became a no-go zone,” Westlake says. “What were we going to use instead?”

Other available preservatives were effective against one or other of the contaminants but not all of them. Cosmetic ingredient manufacturers had to scramble to come up with a system that worked and was still safe when different ingredients were combined.

“There were alternatives that were okay for six months to a year and then stopped being effective. A year is not enough for a commercial product,” says Westlake.

The preservative system used now in Evolu’s lotions and creams is a blend of benzyl alcohol and dehydroacetic acid. These are plant-derived and considered safe for use in natural skincare – certainly safer than applying creams full of moulds and yeasts – but they are still synthesised.

A preservative by definition has to be a toxic compound – after all, it is there to kill bacteria and prevent contamination. With a focus on healthy skin and the benefits of plant extracts, Kasza says Evolu is increasingly looking at simpler formulations.

“One of the things we’re doing now is creating more products that are anhydrous [containing no water so not requiring a preservative]. Oils are becoming much more popular and we like to offer that as an option.”

This article was first published in the September 1, 2018 issue of the New Zealand Listener.