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An iodine dressing is a wound dressing that carries an iodine-based antimicrobial, most often povidone-iodine (PVP-I) on a non-adherent fabric, or cadexomer-iodine as a gel. In the United States, FDA files these products under the product code FRO, “Dressing, Wound, Drug”, not as plain gauze.
This page describes products and general use; it is not medical advice.
Who uses it: clinicians and wound-care staff who apply it, and clinic buyers and students who need to tell iodine dressings apart from other dressing families. Reader task: after reading you should be able to name the main iodine dressing types, say how FDA classifies them, and list the handling points a manufacturer or formulary entry states.
What is an iodine dressing?
An iodine dressing is a dressing impregnated with an iodine antimicrobial so the iodine is released at the wound surface. It is a drug-containing dressing, which is why it differs from a plain absorbent pad such as those described in what a wound dressing is.
How is it built?
The best-documented example is 3M’s Inadine (PVP-I) Non Adherent Dressing. Its manufacturer brochure describes a low adherent knitted viscose fabric impregnated with a polyethylene glycol (PEG) base containing 10% povidone iodine, equivalent to 1.0% available iodine. The brochure states that as the povidone iodine is released, the dressing changes colour from orange to white, and that the fabric minimises adherence to the wound bed.
A formulary entry for the same product family describes it as a knitted viscose primary dressing impregnated with povidone iodine ointment 10%, and says it requires a secondary dressing such as a low adherent dressing.
Types and variants
| Type | Form | Stated details |
|---|---|---|
| Povidone-iodine (PVP-I) impregnated dressing | Knitted viscose fabric with a PEG base | 10% povidone iodine, equal to 1.0% available iodine; orange-to-white colour change; used as a primary dressing with a secondary dressing (3M brochure; NHS Grampian formulary entry) |
| Cadexomer-iodine | Gel | FDA 510(k) record K093320 lists “Dryodine cadexomer-iodine gel”, product code FRO, decision 06/18/2010, Substantially Equivalent (FDA) |
Antimicrobial dressings are a broad family; iodine is one active type within it. Silver dressings are a different product family and are not covered here. Povidone iodine dressings and “povidone-iodine dressing” searches refer to the first row above.
How does FDA classify iodine dressings?
FDA product classification code FRO is named “dressing, wound, drug”. The database lists its device class as “Unclassified” with the reason “Pre-Amendment”, the submission type as 510(k), and no regulation number. The cadexomer-iodine gel record K093320 was reviewed by the General and Plastic Surgery panel, with applicant Collegium Pharmaceutical Incorporated. Checked 2026-10-30.
Sizes and specifications
| Product | Listed sizes | Pack size |
|---|---|---|
| Inadine-type PVP-I dressing (Systagenix, as listed in the NHS Grampian formulary entry, third edition, August 2015) | 5 cm x 5 cm; 9.5 cm x 9.5 cm | 25 |
This is one older formulary listing, not a current catalogue; product names and ownership have changed since, so check the current instructions for use for the product you hold.
How to choose
Selection criteria are stated here only at label level. The manufacturer brochure lists its indications as managing ulcerative wounds, and also for prevention of infection in minor burns and minor traumatic skin loss injuries, and says the dressing can be used as a primary dressing in combination with other dressings. The formulary entry lists known iodine hypersensitivity as a contraindication, and also lists severe renal impairment, use on the newborn, pregnancy and lactation. A clinician decides suitability for an individual patient; this page does not.
Safe use and handling basics
- Use a secondary dressing: the formulary entry says a primary iodine dressing requires one.
- Watch the colour: the manufacturer brochure presents the orange-to-white change as an indicator of the dressing’s iodine release.
- Dwell time: the formulary entry says the dressing is unlikely to retain significant antimicrobial activity if left in position longer than two days.
- Quantity: the entry states that no more than four dressings should be applied at one time.
- Absorption: the entry notes iodine may be absorbed, particularly if large wounds are treated, and advises caution in patients with thyroid disease.
For how iodophors fit among skin and wound antiseptics, see what an antiseptic is and skin antisepsis before injection.
Common mistakes
- Treating an iodine dressing as interchangeable with a plain non-adherent pad, when it is a drug dressing with its own contraindications.
- Leaving it in place without a secondary dressing, or beyond the two-day point the formulary entry cautions about.
- Stacking more dressings than the four the entry allows.
- Overlooking iodine hypersensitivity or thyroid disease listed in the contraindications and precautions.
- Using a dated catalogue size or name; the formulary entry cited here is from 2015.
For other dressing families and supply planning, see hydrocolloid wound care and the wound care clinic supply checklist.
FAQ
Is an iodine dressing an antimicrobial dressing?
Yes in product type: the formulary entry lists the Inadine-type product as type “Antimicrobial Iodine”, primary and low adherent. Antimicrobial dressing is the wider family.
What is a povidone iodine dressing?
A fabric dressing impregnated with a PEG base containing 10% povidone iodine, equal to 1.0% available iodine, per the manufacturer brochure.
What is a silver dressing, and is it the same?
A silver dressing is a different antimicrobial dressing family from the iodine types described here.
Is an iodine dressing a regulated device?
FDA lists wound dressings with a drug under product code FRO, class “Unclassified”, submission type 510(k).
Sources
- FDA 510(k) record K093320, Dryodine cadexomer-iodine gel: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMN/pmn.cfm?ID=K093320 (checked 2026-10-30)
- FDA product classification, code FRO: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPCD/classification.cfm?id=FRO (checked 2026-10-30)
- 3M Inadine (PVP-I) Non Adherent Dressing brochure, 2013: https://www.eboshealthcare.com.au/globalassets/ebos-au/microsites/3m/inadine-non-adherent-dressing-brochure-lat-70-2013-1000-3-ebos.pdf (checked 2026-10-30)
- NHS Grampian Joint Wound Care Formulary, Inadine entry, third edition, August 2015: https://www.nhsgrampian.org/globalassets/foidocument/foi-public-documents1—all-documents/WCF_Inadine.pdf (checked 2026-10-30)
