A reader sent me a photograph last month of the back of a moisturiser. The front said “98% naturally-derived ingredients”. The ingredient list, when she enlarged the photo, included sodium lauroyl glutamate, cetearyl olivate, decyl glucoside, and behenyl alcohol, along with a long list of botanical extracts. She wanted to know whether the 98% claim was true, and whether the synthetic-sounding names disqualified the product from the label.
The answer is more interesting than yes or no.
“Naturally-derived” is a phrase with no default legal definition in most markets. In the US, the FDA does not regulate it. In the EU, neither the Cosmetics Regulation nor the EU Eco-label scheme cover the phrase as it appears on conventional product packaging. There are voluntary standards (ISO 16128 internationally, COSMOS through the European certifying bodies, Ecocert, the Soil Association, NaTrue) that do define it. Most brands using the phrase do not certify against any of those standards. The phrase, on a bottle, often means whatever the brand wants it to mean.
The chemistry is the part where this gets interesting, because the standards that do define “naturally-derived” do so in ways that allow a remarkable amount of chemical transformation while still letting the resulting molecule count as natural. I want to walk through that.
What the standards actually say
ISO 16128 is the international voluntary standard for cosmetic natural-content claims. It was published in two parts, in 2016 and 2017. Most major cosmetic brands that make natural claims align with ISO 16128 even if they do not certify against COSMOS. The standard defines four categories of cosmetic ingredient:
- Natural ingredients: substances composed of natural origin obtained from plants, animals, microorganisms, or minerals, with only physical processing allowed (cold pressing, distillation, fermentation, extraction with water or ethanol). No chemical modification.
- Derived natural ingredients: substances with greater than 50% natural origin by molecular weight, obtained from natural sources via defined chemical reactions. The chemical modifications allowed are extensive. Saponification, esterification, hydrolysis, hydrogenation, and many other transformations are permitted.
- Non-natural ingredients: substances not meeting the above criteria.
- Natural water (water sourced from natural processes, treated separately because water dominates most cosmetic formulations by mass).
This is the part most consumers do not realise. ISO 16128’s “natural origin index” (NOI) is calculated based on the percentage of the molecule that traces back to natural starting material. A surfactant like decyl glucoside, which is synthesised from coconut-derived fatty alcohols and corn-derived glucose, has an NOI very close to 1.0 because both starting materials are natural even though the molecule itself is synthesised in a reactor.
A “98% naturally-derived” claim under ISO 16128 can include a long list of ingredients that look synthetic on the INCI label. Cetearyl olivate, the moisturiser ingredient I mentioned at the top, is an ester of cetyl/stearyl alcohol with olive oil fatty acids, made by chemical esterification. Under ISO 16128, it qualifies as derived natural with a high NOI.
COSMOS is the stricter standard. COSMOS-certified products have to meet additional criteria: a minimum percentage of organic ingredients, restrictions on permitted preservatives (no parabens, no phenoxyethanol in most cases, only a defined list of “naturally identical” preservatives), and a requirement that processing aids and solvents come from a defined “green chemistry” list. COSMOS Natural requires that 95% of the agro-ingredients be from organic farming (where agro-ingredients are the plant-derived ingredients, not water or minerals).
NaTrue, run out of Brussels, is in a similar bracket to COSMOS but with slightly different specifics.
The Ecocert standard predates ISO 16128 and is now mostly absorbed into the COSMOS standards.
What survives the chemistry
This is the part I find most useful to think about as a consumer.
Some ingredients labelled “naturally-derived” are essentially the same molecule as the natural source. Sweet almond oil that has been cold-pressed and filtered is, chemically, the same triglyceride mixture that was in the almond. Shea butter that has been refined and bleached has been processed but the major fatty acid composition is intact. These are natural by any reasonable reading.
Other ingredients labelled “naturally-derived” have been transformed so thoroughly that the original biological molecule is unrecognisable. Sodium lauroyl glutamate is a surfactant made by reacting glutamic acid (from sugar fermentation) with lauroyl chloride (from coconut or palm fatty acids, after chemical chlorination). The end molecule is in the same family as soap but is not present in any natural source in any meaningful amount. ISO 16128 still counts it as naturally-derived because the carbon atoms trace back to plant sources.
Cetearyl olivate is somewhere in the middle. The fatty acids are unchanged from the olive oil they came from. The alcohol they are esterified to (cetyl/stearyl) is naturally occurring in many sources. The esterification reaction is what humans do industrially. The molecule itself does occur, in trace amounts, in some natural sources.
Where I think the labelling falls short of useful is in not distinguishing these three cases. The cold-pressed almond oil and the sodium lauroyl glutamate are both 100% naturally-derived under ISO 16128. They are not the same thing, and a consumer choosing “natural” because they want minimal chemical processing is not getting what they think they are getting.
The contrarian view I hold
I want to be careful here because the “naturals are dangerous” backlash has its own problems, and I am not going to make that argument.
The argument I want to make is narrower. “Naturally-derived” as a label means almost nothing in terms of cosmetic safety, sustainability, or skin compatibility. The variables that actually matter are downstream of the natural-versus-synthetic question.
A coal-tar derived synthetic fragrance is irritating. A “natural” essential oil mixture is often more irritating because the concentration of allergens (citral, limonene, linalool oxides) can be higher. Bergamot oil contains bergapten and can cause phototoxic reactions. Citrus peel oils more generally are common contact allergens. The “natural fragrance” label does not protect a consumer from any of this and may give a false sense of safety.
The reverse case is also true. Synthetic squalane (from sugarcane fermentation, or from olives via the COSMOS-friendly pathway) is in most respects identical to natural squalene, with the advantage that the synthetic version does not oxidise the way the shark-liver-derived version does, and the disadvantage of nothing. Phenoxyethanol, a preservative widely banned from “natural” formulations, has a better safety record in cosmetic use than many of the “natural” preservatives it has been replaced with (some of which sensitise more readily, some of which fail to preserve the formulation adequately and lead to microbial contamination).
The “naturally-derived” label as deployed on conventional packaging does not solve any of these real safety questions. It is largely a marketing artefact attached to a chemistry distinction that is more permissive than consumers realise.
If you want a label that actually means something, the certifications (COSMOS Organic, COSMOS Natural, NaTrue, the Soil Association in the UK) are the ones to look for. The ingredients in a COSMOS-certified product are constrained in ways that the “naturally-derived” claim alone is not.
What I would tell my past self
If I could go back to the version of me who first started reading cosmetic ingredient lists in 2014, I would say three things.
The label “naturally-derived” is not a meaningful filter. Either look at the actual INCI list and learn what the ingredients are, or look for a third-party certification (COSMOS, NaTrue, USDA Organic for personal care) that constrains the formulation in a documented way.
Natural origin is not a safety guarantee. Many of the most common contact allergens in cosmetics are botanical extracts and essential oils. Some of the most well-tolerated cosmetic ingredients are synthetic.
The chemistry of “naturally-derived” allows a remarkable amount of transformation. If you would not recognise the synthesised molecule as something that came from the plant on the label, that is because, in many cases, it did not, in the sense the marketing implies.
The reader who sent me the moisturiser photograph ended up keeping the product. The cetearyl olivate did not bother her once she understood what it was. The “98% naturally-derived” claim, she said, no longer carried weight either way.
FAQ
Is ISO 16128 a regulation?
No. It is a voluntary standard that brands can choose to align with. There is no government enforcement of compliance. Brands that align with it generally do so because it gives them a defensible methodology for natural-content claims, not because they are required to.
What is the difference between COSMOS and ISO 16128?
COSMOS is stricter. It requires defined organic agriculture content, restricts permitted preservatives and processing aids, and is third-party certified. ISO 16128 is a methodology for calculating natural-origin content and does not require certification. A product can claim ISO 16128 alignment without anyone verifying it. A COSMOS-certified product has been audited.
Are “naturally-derived” preservatives safer than parabens?
The evidence does not support this. Parabens have one of the longest safety records in cosmetic chemistry. The “natural” replacements (radish-root ferment, certain levulinic acid preparations, blends of organic acids) have shorter records and a mix of sensitisation reports. The paraben backlash was driven by one paper (Darbre 2004) whose methodology has been criticised at length.
Does “100% natural” exist?
By the strictest reading, almost no cosmetic is 100% natural. Water counts, but preservation, emulsification, and many other functions require processed ingredients. Some bar soaps and pure oils come close. A “100% natural” cream is usually leaning on either a generous definition of naturally-derived or a very short shelf life.
Should I avoid synthetic ingredients?
There is no good reason to do so as a blanket rule. There are good reasons to avoid specific ingredients (certain fragrance allergens, methylisothiazolinone, formaldehyde donors at higher concentrations) and some of these are synthetic. Some are natural. The category is not the right level of analysis.
References
ISO 16128-1 (2016) and ISO 16128-2 (2017). Cosmetics – Guidelines on technical definitions and criteria for natural and organic cosmetic ingredients and products.
COSMOS-standard documentation, COSMOS-standard AISBL, 2010-present.
Darbre PD, et al. (2004). Concentrations of parabens in human breast tumours. J Appl Toxicol. (Cited here for the role this paper played in driving the natural-preservative shift, not as endorsement of its conclusions.)