How we classify

A note on methodology, written for the customer who asks the right question: "what makes you the one who decides?"

Every ingredient in this database carries a verdict. We've been asked, increasingly often, what those verdicts mean and how they're assigned. This page is the answer.

Two systems, one purpose

PrimalBasics maintains two distinct instruments. The first is The 0% Standard™ — fourteen named, mechanistically-justified exclusions that we will never include in our own products. It is a brand promise. It is fixed. We grow it slowly, deliberately, and only when a new mechanism justifies a new exclusion.

The second is the Verdict system you're using right now — a four-tier classification we apply to every cosmetic ingredient we examine. It is broader than The 0% Standard because the world is broader than our fourteen rules. Most ingredients in cosmetics are not on our exclusion list. That doesn't mean we would put them in our own products. The Verdict system tells you the difference.

The four criteria for 0% Approved

To earn 0% Approved — the highest classification in the Verdict system — an ingredient must pass all four criteria. They are applied in order.

Criterion 1 — Naturalness

The ingredient must originate from a recognisable natural source — plant, mineral, or traditional fermentation — and be transformed through processing that preserves the integrity of that source.

Acceptable processing methods include cold pressing, steam distillation, CO₂ extraction, water-based extraction, fractional distillation, hydrogenation, esterification of plant fatty acids and glycerin, traditional saponification, and glycoside formation. Each of these methods has a long industrial history, produces ingredients with characterised molecular structures, and does not introduce contaminants beyond trace residuals well below regulatory limits.

What does not pass Criterion 1: petroleum-derived ingredients, synthetic compounds built from non-renewable feedstocks, processing methods that introduce known contaminants (such as 1,4-dioxane in ethoxylated surfactants), and ingredients whose origin cannot be traced to a natural source.

The principle is simple: natural feedstock plus acceptable processing equals natural enough. We do not require that an ingredient be picked from a tree and dropped into a bottle. We require that what enters the product be honestly traceable to the natural world.

Criterion 2 — Function necessity

Every ingredient in a 0% Approved formulation must serve a defined role. Function is recognised when the ingredient contributes to any of:

• Mechanical, biological, or therapeutic action on the body — cleansing, moisturising, antimicrobial activity, anti-inflammatory effect, antioxidant protection, mineral provision, exfoliation, sun protection, or other measurable contribution.
• Formulary support — carriers, emulsifiers, natural antioxidants that prevent rancidity, viscosity modifiers, and natural preservation systems that allow the formula to exist as a stable product.
• Sensory experience and ritual — aroma, flavour, and texture that contribute to the product's experiential function. The pleasure of using a product is part of why people use it.

Natural plant extracts and essential oils typically deliver multiple categories simultaneously. Cinnamon in oral care delivers flavour and antimicrobial action against oral pathogens. Geranium in deodorant delivers scent and antimicrobial activity against the bacteria that cause underarm odour. Peppermint delivers flavour, antimicrobial action, and circulatory effects. The multifunctional nature of natural ingredients is a feature, not a deficiency — and we count every functional contribution when applying this criterion.

What does not satisfy Criterion 2:

• Marketing decoration. Ingredients added at trace levels far below any functional or sensory threshold, included purely for label appeal. The industry calls this "fairy dusting."
• Synthetic decoration. Synthetic colourants, glitters, and synthetic fragrance compounds whose only purpose is appearance or scent — without therapeutic value, ritual contribution, or natural origin.

Criterion 3 — Safety profile

An ingredient passes Criterion 3 when there is no credible documented harm at the concentration, route, and duration of exposure used in the product.

The 0% Standard distinguishes carefully between two different things that are often confused:

• Labelling presence on regulatory schedules — for example, the EU-26 fragrance allergen list. These schedules exist to support informed choice for sensitised individuals. Listed presence is not a safety prohibition; it is an information requirement.
• Documented harm at use level — population-level evidence of injury, sensitisation, endocrine activity, photo-toxicity, or reproductive effect at the actual concentration, route, and duration of exposure in the product.

The bar is the second. A naturally-sourced ingredient at a concentration well within IFRA Category limits, with no population-level evidence of harm at that use level, passes Criterion 3 — even if its constituent compounds appear on EU-26.

An ingredient fails Criterion 3 when documented evidence shows any of the following at human-relevant exposure levels:

• Endocrine activity demonstrated in vivo or in epidemiological data — not in-vitro alarm-only.
• Phototoxicity or photo-sensitisation at the extraction method and concentration used. Cold-pressed citrus oils with intact furocoumarins in leave-on products fail this. Steam-distilled and FCF (furocoumarin-free) versions of the same plant do not — the chemistry is materially different.
• Substantial population-level contact sensitisation at typical use levels — beyond labelling presence, with documented harm in the actual exposure pattern.
• Mucosa-specific harm for oral, ocular, or intimate-care products. The evidence base must show population-level damage at the formulation's actual use level — concentration, duration, residence time, rinse pattern. Individual case reports do not constitute population-level evidence.
• Regulatory restriction or recent reclassification under EU, US FDA, or comparable cosmetic safety frameworks at the use levels in question.

An ingredient receives Borderline classification when concentration approaches or exceeds IFRA Category limits without label disclosure, when an in-vitro signal exists with no human-relevant follow-up, or when the dose-response curve crosses into recognised sensitisation territory for a meaningful share of the population.

Two principles shape every Criterion 3 evaluation:

The dose principle. Safety is concentration-dependent. An ingredient harmful at 5% may be entirely benign at 0.05%. We evaluate exposure, not isolated chemistry.

The natural-source principle. Naturally extracted plant materials at use-appropriate concentrations pass Criterion 3 in the absence of specific documented harm at those concentrations. Centuries of empirical evidence in traditional preparations and modern formulary inform this position.

Criterion 4 — Formulary precedent

Defensible as something PrimalBasics would ourselves formulate with at this point in time. This criterion has two parts.

Editorial defensibility. The ingredient must be one we can stand behind to a curious customer, an industry skeptic, or a journalist asking why we use it. Passing the other three criteria is the foundation of that defensibility — but the formulary judgment is also legitimate. We may decline to use an ingredient that meets the other three criteria if we have a credible reason — better alternative, ethical sourcing concern, supply-chain reliability, or simple aesthetic preference for a cleaner option.

The fairness rule. PrimalBasics applies the same Criterion 4 bar to its own formulations that the verdict tool applies to competitor products. We do not invent exceptions for our own catalog. The bar is the bar. Where our own products do not pass, we say so publicly and either reformulate or accept a lower rating with explanation.

The four tiers

0% Approved — passes all four criteria. PrimalBasics-grade. The ingredients we'd put in our own formulas.

Acceptable — natural source, no documented harm at use level, but more processed than 0% Approved or otherwise more conservative on Criterion 1. Reasonable on a label. We wouldn't formulate with these — cleaner alternatives exist for our category — but they're not a problem if you encounter them.

Borderline — documented concerns at use level worth knowing about. EU-26 allergens at concentrations approaching IFRA limits without disclosure, in-vitro signals without human-relevant follow-up, or known sensitisation pathways for a meaningful share of users. Not banned, but flag-worthy. We do not formulate with these.

Fails — hits one of the 14 Exclusions, has substantial documented harm at use level, or serves no necessary function that a clean alternative could not cover. We never use these.

How we apply this to our own products

We hold PrimalBasics products to the same four criteria, applied with the same expert judgment, that we apply to every competitor product in the verdict tool. Where our own formulations are reviewed and pass, we say so. Where they sit at Acceptable, Borderline, or Fails, we say so publicly — either with reformulation underway, or with explicit explanation of why the formulation choice stands.

We commission an internal audit against this methodology each time the methodology is revised. The audit is the test we have to pass before the methodology is the bar we hold others to. Brands that will not run this test fail it by default.

Where we change our mind

This methodology will evolve. The cosmetic chemistry literature evolves. Regulatory frameworks evolve. Our own understanding of formulary and safety evolves. When we update the methodology, the previous version remains accessible and the change is documented. We do not rewrite history quietly.

The methodology was first published on May 2, 2026. It was revised the same day in response to a public reformulation honesty audit that surfaced where the original criterion language was stricter than the dose principle and natural-source principle the methodology was built on. The revision made explicit what the framework already assumed.