Quick facts
- A blood and plasma warming device brings a unit of blood or plasma to a stated temperature before it is administered — the in-line warmer in a rapid transfusion, the fluid warmer in surgery, and the blood-bank warming bath.
- In the United States the regulation splits by energy source: 21 CFR 864.9205 places the nonelectromagnetic warmer at Class II (performance standards) and the electromagnetic warmer at Class III (premarket approval).
- The openFDA device classification API carries the same split in the product codes: BSB for a non-electromagnetic warmer, KZL for a blood and plasma warming device, and BSA for an electromagnetic warmer at Class III.
- On the same regulation, the United States notes that no effective date has been established for the premarket approval requirement for the electromagnetic device.
- Canada does not split by energy source. The warmer modifies blood by the exchange of heat, so Rule 6(3) of Schedule 1 places it at Class II.
- Entries, classes, product codes and rule text below were checked against the eCFR, the consolidated Regulations and the openFDA classification database on 2026-10-14.
A blood or plasma warming device raises the temperature of a unit before it is given. It is used in rapid transfusion, in surgery where large volumes are replaced, and in the blood bank where a unit is brought back to a stated temperature before issue. Warming blood is not a neutral act: red cells are damaged by heat above the limit the manufacturer states, so the device is regulated on how it delivers that energy. The United States writes the split into the regulation itself, and it turns on the method used to warm. Canada reaches one class from a rule about how blood is modified. This article sets out both routes and the record a service keeps, with the nitrile examination gloves used at the same bench.
What is a blood and plasma warming device?
It is a device that warms blood or plasma before administration. In its simplest form it is a controlled water bath or dry-heat block that brings a unit to a stated temperature before issue. In its more common form in surgery it is an in-line unit that warms the fluid as it passes through tubing toward the patient, so the infusion reaches the vein at a temperature the clinician has chosen rather than at room temperature or below.
The distinction from a laboratory tube warmer is worth stating, because the two are bought by the same departments. A tube warmer brings a small sample to 37 degrees for a method that needs it — a pre-analytical step on a specimen that will be analysed. A blood and plasma warming device acts on a unit that is intended for transfusion, and what happens to that unit is regulated on the transfusion path rather than as a laboratory accessory.
What class is a blood and plasma warming device in the United States?
The regulation answers in two paragraphs. 21 CFR 864.9205 first identifies a nonelectromagnetic blood and plasma warming device as one that warms blood or plasma, by means other than electromagnetic radiation, prior to administration, and classifies it at Class II (performance standards). It then identifies an electromagnetic device as one that employs electromagnetic radiation, radiowaves or microwaves, to warm a bag or bottle of blood or plasma prior to administration, and classifies it at Class III (premarket approval). The section adds that no effective date has been established for the premarket approval requirement for the electromagnetic device.
That last sentence is the kind of detail a purchaser rarely sees and a supplier should be able to explain. The two paragraphs describe the same clinical job, warming a unit before it is given, and reach different classes because of the way the energy is delivered. The openFDA device classification API reflects the split at product-code level: BSB (Warmer, blood, non-electromagnetic radiation) and KZL (Device, warming, blood and plasma) at Class II, and BSA (Warmer, blood, electromagnetic radiation) at Class III.
| Item | Detail |
|---|---|
| US regulation | 21 CFR 864.9205 - Blood and plasma warming device |
| Nonelectromagnetic warmer | Class II (performance standards), product code BSB |
| Electromagnetic warmer (radiowaves or microwaves) | Class III (premarket approval), product code BSA |
| Blood and plasma warming device code | KZL, Class II |
| Noted in the regulation | No effective date established for the premarket approval requirement for the electromagnetic device |
| Applied to | A bag or bottle of blood or plasma, prior to administration |
How does Canada classify a blood and plasma warming device?
Canada keeps no named entry, so the class is derived from Schedule 1 of the Medical Devices Regulations. The device is not an in vitro diagnostic device — it does not examine a specimen — so the Part 1 rules apply. Two of them point at this article of equipment. Rule 5 places a non-invasive device intended for channelling or storing gases, liquids, tissues or body fluids for the purpose of introduction into the body by means of infusion or other means of administration at Class II; a warmer that sits in the infusion path is such a device. Rule 6(1) takes a device intended for modifying the biological or chemical composition of blood for the purpose of introduction into the body by infusion and places it at Class III, and Rule 6(2) lifts a device that may introduce a potentially hazardous foreign substance to Class IV.
Rule 6(3) is the subrule that decides the question, and it is the one a reader should quote. It provides that a device described in subrule (1) that accomplishes the modification by centrifugation, gravity filtration or the exchange of gas or heat is classified as Class II. A blood warmer modifies the unit by heat exchange and adds no reagent and no foreign substance, so subrule (3) applies and the class is Class II — on the reading taken here, and regardless of whether the unit warms by a water bath, a dry block or an in-line electromagnetic element. That is where the two systems diverge: the United States writes the energy source into the class, and Canada reads the energy source only through the modifying rule, which returns the same class for a device that changes nothing but temperature.
| Item | Canada | United States |
|---|---|---|
| Named entry | None; classified by rule | 864.9205 - Blood and plasma warming device |
| Class, non-electromagnetic warmer | Class II (Rule 6(3)) | Class II (performance standards) |
| Class, electromagnetic warmer | Class II (Rule 6(3)); Class III only if Rule 6(1) or a hazardous-energy reading applies | Class III (premarket approval) |
| Governing text | Schedule 1, Part 1, Rules 5 and 6(3) | 21 CFR 864.9205 |
| Route to market | Device licence (Class II) with quality-system evidence | Premarket notification, or premarket approval for the electromagnetic device |
Which warming rule applies, and which is the near miss?
Three rules sit close to this device, and it is worth naming each so the reading can be checked. Rule 5 reaches the channelling and storage of fluids for introduction into the body; a warmer in the infusion line is part of that path, and it gives Class II. Rule 6(1) reaches the modification of blood for introduction into the body and gives Class III, with subrule (3) returning a modification accomplished by centrifugation, gravity filtration or the exchange of gas or heat to Class II. Rule 9(1) reaches an active therapeutic device used to administer or withdraw energy to or from the body and gives Class II, with subrule (2) lifting a potentially hazardous administration of energy to Class III.
Rule 9 is the interesting near miss, because a warmer does deliver energy. The energy it delivers goes into the unit of blood rather than into the patient, and the blood then enters the patient at the temperature the clinician selected — which is why Rule 6, the rule written about blood on its way to being given, fits the device more exactly than the rule written about energy delivered to the body. A service writing its own justification should state the rule it relies on and keep the manufacturer's stated temperature limit alongside it, because that limit is the fact the device is designed around.
| Rule | What it covers | Class | Applies to a warmer? |
|---|---|---|---|
| Rule 5 | Channelling or storing fluids for introduction into the body | II | Yes; the warmer sits in the infusion path |
| Rule 6(1) | Modifying the biological or chemical composition of blood for introduction into the body | III | Not on the reading taken here once subrule (3) applies |
| Rule 6(3) | A modification accomplished by centrifugation, gravity filtration or the exchange of gas or heat | II | Yes; warming is heat exchange |
| Rule 9(1) | An active therapeutic device used to administer or withdraw energy to or from the body | II | The energy is delivered to the unit rather than to the body |
| Rule 9(2) | A potentially hazardous administration or withdrawal of energy | III | Only if the energy delivery were potentially hazardous |
What should a service check before ordering a warmer?
Four checks. First, confirm the method the unit uses to warm, because in the United States that single fact decides between a Class II entry and a Class III entry, and the labelling should say which one applies. Second, confirm the manufacturer's stated temperature limit and the alarm and cut-out behaviour above it, since that limit is what protects the red cells. Third, confirm the tubing and set the unit is qualified with, because an in-line warmer is only validated with the disposables the maker lists. Fourth, confirm the calibration or verification routine the maker states and how a temperature deviation is detected, because a warmer that drifts is a device that fails silently.
A transfusion or perioperative service also reorders the consumables used at the same warming station. Clinics that stock for a whole practice can order through the wholesale programme and request a bulk quote for a standing or annual order; the nitrile examination gloves, 4 mil sits in the same catalogue. Consumables for this line are listed under diagnostic laboratories. Reselling? become a distributor.
How does the class affect the record a transfusion service keeps?
The class sets the market-entry path; the record is set by the practice. A warmed unit is recorded with the unit number, the device used, the set temperature or the setting selected, the time the unit left the controlled storage and the time it was given, and the identity of the clinician who gave it. Where the device keeps its own log, the log is filed with the transfusion record rather than kept only on the device.
The routine also includes the verification the maker states at the interval the maker states, the alarm test, and the action taken when the device records a temperature outside its window. None of that changes with the class; it is the ordinary routine of a service that warms blood, and the record is what shows the unit was warmed as the maker intended.
Sources
- openFDA device classification API
- Medical Devices Regulations, SOR/98-282, full text and Schedule 1
- US FDA, medical device databases
- US FDA, overview of device regulation
- Health Canada, medical devices
- Health Canada, establishment licensing
- Clinical and Laboratory Standards Institute
- Public Health Ontario, infection prevention and control
- ISO 15189:2022, medical laboratories, requirements for quality and competence
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, application of risk management to medical devices
- ISO 17511:2020, metrological traceability of values assigned to calibrators
- World Health Organization
- Standards Council of Canada
- CSA Group
- CCOHS, OSH answers
- Health Canada, medical device licence application guidance
A warmer check sheet for the transfusion fridge. Unit number, set temperature, alarm test and the clinician who signed off fit on a single page that stays with the unit record. Open the compliance log centre and take the blank sheet — no account and no sign-up, and the service can print as many copies as it runs units.
A month of checks, already dated. Enter the service name, the device and the check list once, and the sterilization log generator returns a dated sheet you can print and file straight into the quality manual.
Ask a compliance specialist. A classification question usually turns on how the device is used, not only on its name. Ask a compliance specialist — you get a written answer specific to your equipment and province, with the regulation or standard it is based on cited.
Related reading
- Blood tube mixers and warmers in Canada vs the US
- Hematocrit tubes and readers in Canada vs the US
- Platelet aggregometers in Canada vs the US
CliniEco Medical supplies eye care, laboratory and dental consumables of the kind described in this article. MDEL #35334. This article is written for optometry, laboratory and dental procurement professionals and is not legal advice; the class of a device and the records a practice keeps belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
What class is a blood and plasma warming device in the United States?
It depends on the paragraph. 21 CFR 864.9205 places the nonelectromagnetic warmer at Class II with performance standards, and the electromagnetic warmer at Class III with premarket approval.
What class is it in Canada?
Class II on the reading taken here. Rule 6(3) of Schedule 1 returns a device that modifies blood by the exchange of heat to Class II, and Rule 5 reaches a device that channels or stores fluids for introduction into the body at Class II.
Why does Canada not split the class by energy source?
Because the Canadian rules classify by what the device does to the blood. Rule 6(3) names the exchange of gas or heat, which covers a warmer of any design; the power source is not itself a classification criterion.
Is a blood warmer the same as a laboratory tube warmer?
No. A tube warmer brings a sample to 37 degrees for a method that needs it, which is a pre-analytical step on a specimen. A blood and plasma warming device acts on a unit intended for transfusion, and it is regulated on that path.
Does the regulation really note that no effective date has been set for premarket approval?
Yes. The paragraph on the electromagnetic device states that no effective date has been established for the requirement for premarket approval for that device, which is why the distinction between the two paragraphs matters to a supplier.
What else is a blood and plasma warming device called?
It is also written as blood warmer, fluid warmer, in-line warmer, infusion warmer and blood warming bath; the US regulation describes the same article as a device that warms blood or plasma prior to administration.
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