A standard adhesive bandage has three main parts: a flexible backing strip, a pressure-sensitive adhesive, and an absorbent wound pad. Each layer is made from different materials, and the specific composition varies depending on whether you’re using a basic plastic strip, a fabric bandage, or a newer hydrocolloid type.
The Backing Strip
The backing is the outer layer you see and touch. On most inexpensive bandages, it’s a thin plastic film made primarily from polyethylene, a common flexible polymer. Many manufacturers use a blend of low-density polyethylene and linear low-density polyethylene, sometimes layered with an elastic inner core to help the bandage stretch and conform to skin. That elastic layer can include materials like ethylene vinyl acetate or specialty copolymers that give the strip its ability to move with your body without peeling off.
Fabric bandages use woven or knitted textiles instead of plastic film. These are typically made from cotton, polyester, or a blend of both. Fabric backings breathe better than plastic and tend to stick more securely during activity, which is why they’re marketed for heavy-duty or flexible use. Some premium bandages combine a fabric weave with an elastic material to create a backing that stretches in multiple directions.
The very first commercial adhesive bandage, invented in 1920 by a Johnson & Johnson employee named Earle Dickson, was far simpler: surgical adhesive tape with a strip of sterile cotton gauze, covered with crinoline (a stiff, starched cotton fabric originally used in petticoats) to keep everything clean until use.
The Adhesive Layer
The sticky part of a bandage is typically an acrylic polymer, a type of plastic-based adhesive designed to bond to skin at body temperature without needing water or heat to activate. Acrylic adhesives are the current standard because they hold well, remove relatively cleanly, and cause fewer allergic reactions than older rubber-based formulas.
Some bandages still use rubber-based adhesives, which contain natural or synthetic rubber mixed with sticky resins like colophony (also called rosin, derived from pine trees). These tend to stick more aggressively but are more likely to cause skin irritation. Colophony is by far the most common allergen in bandage adhesives. A large analysis of allergic reactions to medical adhesives between 2001 and 2018 found that colophony accounted for over 80% of identified allergens. Other potential irritants include acrylates, rubber accelerators, and formaldehyde-based resins.
If your skin turns red, itchy, or blistered under bandage adhesive, you’re likely reacting to one of these compounds. Switching to a bandage labeled “sensitive skin” or “hypoallergenic” usually means the adhesive is a purified acrylic formula with fewer of these additives.
The Wound Pad
The white rectangle in the center is an absorbent pad, almost always made from cotton or rayon fibers, sometimes blended with cellulose. This pad is designed to absorb blood and wound fluid while sitting against the skin without sticking to the wound itself. On many bandages, the pad has a thin non-stick facing made from a perforated polymer film that prevents fibers from embedding in the healing tissue.
Medicated bandages add an antiseptic to this pad. The most common active ingredient is benzalkonium chloride at a concentration of 0.13%, a mild antiseptic that kills bacteria on contact. Some specialty wound dressings use silver ions instead, which provide longer-lasting antibacterial protection.
Latex and Allergen Concerns
Natural rubber latex was once a standard ingredient in bandage adhesives and elastic components. Most major brands have moved away from it, but the labeling can be confusing. The FDA discourages manufacturers from using the phrase “latex-free” because products made without latex can still pick up trace latex proteins during manufacturing or packaging. The preferred label is “not made with natural rubber latex,” which tells you the material wasn’t intentionally included but doesn’t guarantee zero contamination. If you have a latex allergy, look for that specific wording rather than assuming “latex-free” means completely safe.
Hydrocolloid Bandages
Hydrocolloid bandages, popular for blisters and acne patches, work differently from standard adhesive strips. The active layer contains gel-forming agents, originally a combination of gelatin, pectin, and carboxymethylcellulose. Modern versions may also include alginate (from seaweed), guar gum, or xanthan gum. These substances absorb moisture from the wound and form a soft gel that keeps the area moist, which speeds healing and reduces scarring. The outer layer is a waterproof polyurethane film that seals everything in and keeps bacteria out.
Liquid Bandages
Liquid bandages skip fabric and adhesive entirely. When you brush or spray them on, a solvent evaporates and leaves behind a thin, flexible polymer film directly on your skin. The specific polymer depends on the product’s base: water-based versions use a polymer called polyvinylpyrrolidone, while alcohol-based formulas rely on nitrocellulose (the same compound used in nail polish). Silicone-based versions contain acrylate or siloxane polymers dissolved in solvents like hexamethyldisiloxane.
For deeper cuts that would otherwise need stitches, medical-grade liquid adhesives use a compound called octylcyanoacrylate. It’s chemically related to superglue but formulated with longer molecular chains that make it less toxic to skin. It hardens on contact with the moisture on your skin, bonding wound edges together in seconds. These were first approved for medical use in the U.S. in 1998 and have since appeared in over-the-counter liquid bandage products.
How Bandages Are Sterilized
The wound pad needs to be sterile when it contacts broken skin. About half of all sterile medical devices in the U.S., including wound dressings, are sterilized using ethylene oxide gas. This method is favored because it penetrates packaging and kills microorganisms without using high heat that could melt the plastic backing or degrade the adhesive. The gas is cleared from the product before it reaches store shelves. Other sterilization methods include gamma radiation and steam, but ethylene oxide remains the standard for heat-sensitive products like bandages.