Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
An underpad is a flat, absorbent piece of material placed on a surface, such as a bed or chair, underneath a person to soak up body fluids, most often urine. It is not worn. It is used in healthcare facilities and at home. Nurses, aides, caregivers, facility buyers and students meet it under several names, including bed pad, bedpad and “chux”.
What underpads are
The U.S. National Library of Medicine’s AccessGUDID database lists underpads under the Global Medical Device Nomenclature (GMDN) term 66117, “Absorbent underpad, non-antimicrobial, reusable”. It defines the device as a flat piece of absorbent fabric placed on a surface and under a patient to absorb bodily fluids, typically urine from bladder weakness or incontinence. The same record states that the device contains no antimicrobial agent and is intended for healthcare-facility and home use.
Who uses it. Clinic and care-home staff, home caregivers, and people managing bladder weakness or incontinence at home use underpads; supply buyers and students of nursing and healthcare supply management study the product class.
An underpad is a different product from a worn absorbent brief and from a bedpan. Our adult incontinence product selection guide places underpads as a product laid under the person rather than worn, and notes they are not a sole defence for someone who needs a worn product; they are usually paired with briefs. The bedpan guide covers the container used for toileting in bed.
How underpads are built
The GMDN definition describes the construction in functional terms: a flat absorbent fabric layer that lies on the surface under the person. Specific layer structures, fill materials and backing vary by manufacturer and are listed in each product’s labeling. Product descriptions in the device database are record text only, and the database does not set a sizing or absorbency standard.
Types: disposable and reusable underpads
The main practical split is between pads used once and pads washed and used again. The U.S. Food and Drug Administration (FDA) and the device databases treat the two differently on paper, although both sit in the lowest-risk device class.
| Type | What the source says | Regulatory identity | Source |
|---|---|---|---|
| Disposable underpad (medical disposable bedding, “bedpad”) | Intended to be used by one patient for a period of time and then discarded. | FDA product code KME, “bedding, disposable, medical”; 21 CFR 880.6060; Class I; exempt from premarket notification (510(k)). | 21 CFR 880.6060; FDA product classification database |
| Reusable underpad | Flat absorbent fabric placed under a patient; the AccessGUDID record states “This is a reusable device”. | GMDN 66117; FDA product code FMW, “Cover, Mattress (Medical Purposes)”; 21 CFR 880.6190; Class I; exempt from premarket notification. | AccessGUDID; 21 CFR 880.6190 |
Which product code a given underpad carries depends on how its manufacturer lists it. The code is a regulatory label, not a statement about quality.
How FDA classifies underpads
This is the angle most retail and brand pages leave out. Under 21 CFR 880.6060, medical disposable bedding is “a device intended for medical purposes to be used by one patient for a period of time and then discarded”, and the regulation lists disposable bedsheets, bedpads, pillows, blankets and waterproof sheets as examples. It is Class I (general controls) and exempt from the 510(k) premarket notification process. The same section exempts non-sterile devices from most quality-system manufacturing requirements, except records and complaint files.
A reusable underpad that is listed as a mattress cover for medical purposes falls under 21 CFR 880.6190, which describes a device “used to protect a mattress”; it may be electrically conductive or contain a germicide. It too is Class I and exempt from premarket notification.
The reusable underpad record in AccessGUDID is not labeled sterile and does not call for sterilization before use. FDA’s product classification entry for code KME adds that exemption from most manufacturing controls applies only while the device is not labeled or otherwise represented as sterile.
How to use underpads
An underpad is placed flat on the surface and under the person, so that it lies between the person and the bed or seat and can take up fluid. That is the level of general use the sources support. Fit, positioning, how often a pad is changed, and how to launder a reusable pad are set by the manufacturer’s instructions for use and by the care setting’s own policy, so follow the instructions supplied with the product and your clinical team’s guidance for an individual person.
Safe use and handling basics
- A disposable underpad is for one patient and is then discarded, as the regulation’s definition states.
- A reusable underpad is a reusable device; follow the manufacturer’s labeled care instructions for cleaning between uses.
- The reusable underpad record in AccessGUDID is not labeled sterile and needs no sterilization before use. If a product is labeled sterile, the labeled handling applies.
Common mistakes
- Treating an underpad as a worn product. It is laid under the person and does not replace a brief for someone who needs a worn product.
- Reusing a disposable pad. The disposable bedding definition is one patient, then discard.
- Assuming a size or absorbency standard. No regulation or device record cited here sets one; compare the figures each manufacturer states on its own labeling.
- Mixing up the sterile and non-sterile labels. Classification exemptions described above apply to devices not labeled or represented as sterile; see sterile vs. non-sterile purchasing.
Frequently asked questions
What are underpads?
Underpads are flat absorbent pieces of fabric or other material that are placed on a surface under a patient to absorb body fluids, typically urine from bladder weakness or incontinence. They are also called bed pads or chux, and they come in disposable and reusable types.
How to use underpads?
An underpad is laid flat on a bed or chair beneath the person so it can absorb fluid. Placement details, change frequency and laundering of reusable pads depend on the manufacturer’s instructions for use and the care setting’s policy, so this page does not give step-by-step directions.
Are underpads regulated as medical devices?
Yes. In the United States, disposable underpads are covered by 21 CFR 880.6060 (medical disposable bedding) and reusable ones appear under mattress-cover product code FMW, regulated under 21 CFR 880.6190. Both are Class I and exempt from 510(k) premarket notification.
Are underpads sterile?
The reusable underpad record checked is not labeled sterile and requires no sterilization before use. Check each product’s labeling.
Where can I find incontinence supplies?
Underpads sit alongside other incontinence products; see the catheters, urology and incontinence supplies category. For choosing among worn and placed products, read the adult incontinence product selection guide.
Sources
- AccessGUDID, NLM: device record 00634916081404, GMDN 66117 “Absorbent underpad, non-antimicrobial, reusable” (checked 2026-10-29).
- FDA Product Classification, code KME: bedding, disposable, medical (checked 2026-10-29).
- eCFR: 21 CFR 880.6060 Medical disposable bedding (checked 2026-10-29).
- eCFR: 21 CFR 880.6190 Mattress cover for medical purposes (checked 2026-10-29).
