Sodium benzoate and potassium sorbate in fragrance-free products

Short answer

Sodium benzoate and potassium sorbate are preservatives. The sources we read describe them as antimicrobial agents that keep products from growing microbes, and none lists either as a fragrance ingredient. On this site they therefore do not fail a fragrance-free check. We work from documents and have not tested any products. This page sets out what the sources say about them, and where they stop.

They are preservatives, not fragrance

PubChem (record retrieved 2026-11-14) describes sodium benzoate as “an organic sodium salt resulting from the replacement of the proton from the carboxy group of benzoic acid by a sodium ion”. Among its listed roles are “an antimicrobial food preservative”. It adds that the sodium salt “is used as an antifungal preservative in pharmaceutical preparations and foods.”

For cosmetics, a 2001 safety review abstract (PMID 11766131, International Journal of Toxicology) says sodium benzoate “is the sodium salt of Benzoic Acid used as a preservative, also in a wide range of cosmetic product types”, and that benzoic acid is used “as a pH adjuster and preservative”. Neither is described there as a fragrance.

PubChem’s potassium sorbate record calls it “a potassium salt having sorbate as the counterion” with “a role as an antimicrobial food preservative”. Its entry for the parent acid describes an antimicrobial against “a wide variety of microorganisms, especially yeasts and moulds”, more efficient in acidic conditions. PubChem’s synonym list for potassium sorbate includes a FEMA number (a flavour-industry listing), but its description gives only the preservative role.

The contrast is benzyl alcohol, a neighbour in the same review. The 2001 abstract says benzyl alcohol is “used in a wide variety of cosmetic formulations as a fragrance component, preservative, solvent, and viscosity-decreasing agent”, and PubChem lists a fragrance role for it. That is why it needs its own check. Sodium benzoate shares the word “benz” but is a different substance.

The names on a label

The EU glossary of common ingredient names, Commission Decision (EU) 2019/701 (EUR-Lex, retrieved 2026-11-14), contains these entries:

Label name (INCI)	Glossary entry number
SODIUM BENZOATE	22870
POTASSIUM SORBATE	20005
BENZOIC ACID	2909
SORBIC ACID	23734

PubChem gives CAS numbers 532-32-1 for sodium benzoate and 24634-61-5 and 590-00-1 for potassium sorbate. We did not retrieve rules on where each name must appear on a label, so we state none. For the wider label picture, see how to read an ingredient list and what “parfum” means.

Where the fragrance words actually hide

The words that matter for a fragrance-free check are different. The FDA’s Fragrances in Cosmetics page (retrieved 2026-11-11) says some “unscented” products may contain fragrance ingredients, because a maker may add just enough to mask the smell of other ingredients. See fragrance-free vs unscented, natural fragrance and why “fragrance” hides ingredients. Individual fragrance chemicals, such as linalool and limonene, are covered separately, and the EU allergen list shows which ones the EU makes labels name.

Seeing a preservative on a list says nothing about whether the product also contains fragrance. Read the rest of the list for that.

What the sources say about skin reactions

Being a non-fragrance does not mean being reaction-free for everyone. These are separate, attributed findings, not general conclusions.

• A 2026 review abstract (PMID 42309282, Journal of the American Academy of Dermatology) on allergic contact dermatitis to personal care products names sodium benzoate among “established and emerging” allergens, alongside limonene and linalool hydroperoxides. Its abstract gives no rates for sodium benzoate.
• A 1976 study (PMID 1037096, Contact Dermatitis) patch-tested eczema patients over three years. It reports perfume allergy in 3.6%, sensitivity to sorbic acid in 0.8% and to parabens in 0.3%. This is old and from a clinic population.
• A 2006 case report (PMID 16867007, Australasian Journal of Dermatology) describes occupational allergic contact dermatitis to a sodium benzoate and chloroacetamide combination in a lotion. Patch testing to sodium benzoate alone was negative, which points at the combination partner, not sodium benzoate, in that case.
• The 2001 review abstract reports clinical data showing that benzoic acid and sodium benzoate can produce nonimmunologic contact urticaria, with wheals, erythema and itching. In one study, 2% benzoic acid caused such a reaction, and benzoic acid was not a sensitiser at 2%. It concluded these ingredients could be used at concentrations up to 5%, and that makers should consider these reactions for products for infants and children. It also said the safety tests were not sufficient to support safety where inhalation is a route of exposure. It is from 2001 and we do not know whether later assessments differ.

These sources disagree on emphasis, not on chemistry: sodium benzoate and sorbates appear as occasional sources of reactions, and none shows them to be common. For your own skin, ask a dermatologist or an allergy or dermatology society, not a label.

How common are they?

A 2017 study of 178 facial wet wipes (PMID 28338538, Dermatitis) found sorbic acid derivatives in 39.3% of wipes and sodium benzoate in 24.2%, against fragrance in 63.5% and phenoxyethanol in 53.9%. It counted them as “potentially allergenic ingredients”, which is a list of presence, not a measure of reactions. A 2024 study of cosmetics bought in China (PMID 39153997, Scientific Reports) found benzoic acid (salts) and sorbic acid (salts) among seven traditional preservatives, ranked by prevalence behind phenoxyethanol and methylparaben. It reports that contents were below regulatory limits or in a range generally regarded as safe, and that ingredients with antimicrobial properties could replace or reduce conventional preservatives, with future attention needed on their safety.

That matters for fragrance-free shopping: fragrance-free products still need a preservative, and a preservation system is a trade-off, not an absence. Our pages on phenoxyethanol, parabens, formaldehyde releasers and methylisothiazolinone cover the other common ones. For the related claim “hypoallergenic”, see what hypoallergenic means.

How this site treats them

This is our own rule, not a regulation or medical judgement. Our fragrance-free test reads the maker’s published ingredient list for fragrance, parfum, aroma, perfume, essential oils and fragrance chemicals. Sodium benzoate, potassium sorbate, benzoic acid and sorbic acid are not on it, so a product is not flagged for them. If a product claims fragrance-free and lists them, they are not the reason to doubt it. See also unscented and sensitive do not mean fragrance-free.

What we don’t fully know

We found no regulator text on concentration limits and no source on natural versus synthetic origin, and no reaction-rate abstract for potassium sorbate itself. The reaction studies are few, partly old, and mostly abstracts. The rest is listed under “unknowns” on this page.