Phenoxyethanol is a preservative that can cause allergies. Studies suggest it may have negative effects on the blood, liver, and fertility. It is implicated in endocrine disruption. It can cause serious eye damage.

It is derived from petrochemicals. Its manufacturing process is very polluting because it is energy-intensive (conditions of

very high temperature and pressure are required) and very toxic components are used.

Methylsiothiazolinone is a preservative that has been used to replace parabens after their dangers came to light.

It is highly allergenic and very irritating to the skin, eyes, and respiratory tract. So much so that it has been banned from use in leave-on products in the European Union. Several studies show neuron toxicity in rats. It is highly toxic to aquatic life. It impairs the growth of algae and single-celled organisms, the basis of the entire marine food chain.

Sodium lauryl sulfate is a surfactant, meaning it is a cleansing and foaming agent. It is also a well-known irritant that has been the subject of numerous scientific publications. It attacks the hair, drying it out, weakening it, and irritating the scalp.

It has indeed shown potentially very irritating effects on the skin, eyes, and scalp. It has also shown inflammatory effects on the skin. It is frequently combined with silicones to overcome its irritating effect. By altering the integrity of the skin barrier, it could promote the passage of molecules harmful to the body.

Today, despite suspicions, this ingredient is not subject to concentration restrictions.

Silicones are often added to sulfate-laden shampoos to cover up the negative effects and give hair a shiny appearance. But this superficial layer only masks the problem and suffocates the hair, making it even more fragile.

Most of the time, hair, although shiny, causes problems with oily roots and dry ends.

Butyphenyl methylpropional, also known as Lilial or BMHCA, is a synthetic fragrance substance that has been banned in cosmetic products in the European Union since March 1, 2022. It is classified as a CMR substance (C for Carcinogenic, M for Mutagenic, R for Reprotoxic).

Despite its ban, it was still found in some products as recently as 2025. Unfortunately, it is up to the consumer to check for its presence to protect themselves.

Benzyl Salicylate is one of the 26 fragrance substances identified as an "established contact allergen in humans" by the SCCS (European Scientific Committee on Consumer Safety).

It is also suspected of being an endocrine disruptor. It has indeed shown endocrine activity (in test tubes or in the laboratory), but current scientific data do not allow us to confirm actual activity in humans.