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This page describes products and general use; it is not medical advice.
On this page
A hot/cold water bottle is, in U.S. federal regulation, a container filled with hot or cold water to apply heat or cold to part of the body. This page sets out the regulatory definition, risk class and product code, and shows how the device differs from the hot packs and cold packs covered elsewhere on CASRAI. It is written for clinic staff, buyers and students who need to identify the product class correctly. Facts below were checked against the primary sources listed at the end on 2026-10-30.
What a hot/cold water bottle is
The FDA regulation 21 CFR 880.6085 states: “A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water to apply heat or cold to an area of the body.” In everyday language this is the familiar hot water bottle, and the same container can be filled with cold water for cold application.
Who uses it: the definition covers devices intended for medical purposes, so the class is relevant to clinics, home-care suppliers and anyone maintaining a supplies catalogue; the regulation does not limit it to one setting.
How it is regulated
The FDA lists the device as Class I, subject to general controls. The regulation exempts it from premarket notification (the 510(k) process under subpart E of part 807), subject to the limitations in 21 CFR 880.9. It is also exempt from the quality management system regulation in part 820 except for the requirements on records and complaint files under 820.35.
| Attribute | Value | Source |
|---|---|---|
| Device name (FDA) | Bottle, Hot/Cold Water | openFDA classification record, product code FPF |
| Product code | FPF | openFDA classification record |
| Regulation number | 21 CFR 880.6085 | eCFR |
| Device class | Class I (general controls) | 21 CFR 880.6085(b); openFDA |
| Premarket notification | Exempt, subject to 880.9 limitations | 21 CFR 880.6085(b) |
| QMS regulation (part 820) | Exempt except records and complaint files, 820.35; openFDA GMP-exempt flag Y | 21 CFR 880.6085(b); openFDA |
| Implant | No | openFDA classification record |
For the meaning of the 510(k) pathway and of device classes, see FDA 510(k) premarket notification and FDA medical device classification.
Hot/cold water bottle vs hot pack vs cold pack
The regulatory definition turns on the filling: a container filled by the user with hot or cold water. Other heat and cold products are described on their own CASRAI pages, which should be read for their own classification.
| Product | What defines it | Where covered |
|---|---|---|
| Hot/cold water bottle | Container filled with hot or cold water (21 CFR 880.6085) | This page |
| Hot pack (instant, reusable, moist heat) | Pack types explained in the hot pack guide | How a hot pack works |
| Moist heat pack (hydrocollator, silica gel) | FDA definition and related devices, including electric moist heating pads, set out in the moist heat pack guide | Moist heat pack |
| Instant cold pack | Ingredients and function covered in the cold pack guide | Instant cold pack ingredients |
What to check on a supplier or catalogue record
Because the FDA identifies this class by product code and regulation number, a catalogue entry can be checked against them: product code FPF, device name “Bottle, Hot/Cold Water”, regulation 880.6085, Class I. A mismatch, for example a different regulation number on a product described as a hot water bottle, is a reason to ask the supplier which classification they rely on. The FDA classification record is public in openFDA, so the check does not depend on supplier documents.
Common mistakes
- Treating a hot water bottle as interchangeable with a silica gel moist heat pack or an electric heating pad. They are described separately; see the moist heat pack guide above.
- Assuming 510(k) clearance exists. This class is exempt from premarket notification, so a missing 510(k) number is expected rather than a gap.
- Assuming Class I means no obligations. General controls still apply, and the part 820 exemption retains records and complaint files.
FAQ
What is a hot water bottle?
Under 21 CFR 880.6085 it is a container intended to be filled with hot or cold water to apply heat or cold to an area of the body, when intended for medical purposes. The FDA classifies it as a Class I device with product code FPF.
Hot water bottle vs heating pad: what is the difference?
The hot/cold water bottle definition describes a container filled with water. Electric moist heating pads are treated as a different type of device in the CASRAI moist heat pack guide, which cites CMS for the distinction between electric moist heating pads and silica gel packs. Check each product’s own regulation and instructions for use.
Does a hot water bottle need FDA clearance?
It is exempt from 510(k) premarket notification, subject to the limitations in 21 CFR 880.9.
Sources
- 21 CFR 880.6085, Hot/cold water bottle, eCFR (https://www.ecfr.gov/current/title-21/section-880.6085), checked 2026-10-30.
- openFDA device classification API, product code FPF (https://api.fda.gov/device/classification.json?search=product_code:FPF), checked 2026-10-30.
