Preservatives
Natamycin
Definition
What it is
Natamycin (pimaricin, E235): antibiotic antifungal sprayed on cheese rinds; concerns that regular dietary exposure may reduce therapeutic effectiveness of natamycin-related antifungals.
On the label
Label names covered by this flag
- natamycin
- pimaricin
- e235
Regulation
Regulatory status
No bans or restrictions are recorded for this ingredient in the jurisdictions clearlabel tracks (US, EU, UK, Canada, Japan, Australia/NZ, Brazil).
Explainer
In plain language
Natamycin, also called pimaricin or E235, is a preservative that stops mold and other fungi from growing. It is produced by fermentation of a soil bacterium and is used mainly on the surface of cheese and cured meats, often sprayed or dipped onto the rind. Its job is to extend shelf life by preventing surface mold.
Assessment
Why it is flagged
Natamycin is the same class of compound used medically as an antifungal drug, which is the root of the concern. Some researchers have raised the question of whether regular low-level dietary exposure could contribute to antifungal resistance, though this is debated and not established for the amounts used on food. EFSA re-evaluated natamycin in 2009 and kept it authorized as a surface treatment for cheese and dried sausage, noting that it stays largely on the surface and is used at low levels. Regulators restrict where it can be used and how much can remain on the food. Clear Label flags it so that this antifungal preservative is visible, not because harm at permitted levels is established.
In the aisle
Where it commonly shows up
- Cheese rinds and shredded cheese
- Sliced and packaged cheeses
- Cured and dried sausages
- Some yogurts and dairy products
Practical
Reading the label
It appears as natamycin, pimaricin, or E235, and is often noted as being applied to the surface or used on shredded cheese to prevent caking and mold. It is sometimes listed alongside cellulose in bagged shredded cheese.
Alternatives
If you want to avoid it
Some people choose block cheese they shred at home, or cheeses whose labels list no added surface preservatives. Comparing a wedge to pre-shredded versions of the same cheese usually shows the difference.
FAQ
Common questions
Is natamycin an antibiotic?
It is an antifungal produced by fermentation and belongs to the same family of compounds used as antifungal medicines. On food it is used at low levels as a surface preservative against mold.
Is it allowed in food?
Yes. EFSA re-evaluated it in 2009 and kept it authorized for surface treatment of certain cheeses and dried sausages, with limits on quantity and residue. It is also permitted in the US for similar uses.
Why is resistance mentioned as a concern?
Because natamycin is related to medical antifungals, some researchers have asked whether frequent dietary exposure could affect resistance. This remains a debated question rather than an established effect at the levels used on food.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.