FL-10000U Respiratory Humidifier

K251448 · Flexicare Medical Limited. · BTT · Jan 16, 2026 · Anesthesiology

Device Facts

• Record ID: K251448
• Device Name: FL-10000U Respiratory Humidifier
• Applicant: Flexicare Medical Limited.
• Product Code: BTT · Anesthesiology
• Decision Date: Jan 16, 2026
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 868.5450
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

The Flexicare FL-10000U Respiratory Humidifier is intended to warm and add humidity to gases delivered to patients requiring mechanical ventilation or positive pressure breathing assistance via an endotracheal tube or face mask. For use by trained personnel only within a hospital/institutional environment. This device is intended to be used with the Flexicare Autofill Humidification Chamber and Flexicare Heated Wire Breathing Circuit.

Device Story

Electrically powered respiratory humidifier; conditions inspired gases for ventilated patients. System includes humidifier base, autofill humidification chamber, and heated wire breathing circuit. Heater plate warms water in chamber; gases gain heat and humidity as they pass through. Heated wire adaptors maintain gas temperature through breathing tubes to patient. Operated by trained personnel in hospital/institutional environments. Device sits between ventilator and breathing system. Temperature probes monitor gas warmth; device controls chamber temperature and heated wire current to achieve desired humidity/temperature levels. Output is warmed, humidified gas; helps prevent airway drying and maintains patient respiratory comfort during mechanical ventilation.

Clinical Evidence

No clinical data. Substantial equivalence supported by bench performance testing, including biocompatibility (ISO 10993-1, ISO 18562-1), electrical safety (ANSI AAMI ES60601-1), EMC (IEC 60601-1-2), and respiratory humidification performance (ISO 80601-2-74).

Technological Characteristics

Polycarbonate housing; pass-over heating method; 150W heater plate. YSI temperature sensing. Class I electrical protection; Type B applied part; IPX1 drip proof. Connectivity via heated wire adaptor leads and temperature sensor leads. Software-controlled safety cutoffs (110°C) and heater plate over-temperature cutout (115 ± 3°C). Complies with IEC 60601-1, IEC 60601-1-2, ISO 80601-2-74, and IEC 62304.

Indications for Use

Indicated for patients requiring mechanical ventilation or positive pressure breathing assistance via endotracheal tube or face mask in hospital/institutional settings. For use by trained personnel only.

Regulatory Classification

Identification

A respiratory gas humidifier is a device that is intended to add moisture to, and sometimes to warm, the breathing gases for administration to a patient. Cascade, gas, heated, and prefilled humidifiers are included in this generic type of device.

Predicate Devices

• Flexicare FL-9000U Respiratory Humidifier Base (K161314)

Submission Summary (Full Text)

{0}

FDA U.S. FOOD & DRUG ADMINISTRATION

January 16, 2026

Flexicare Medical Limited.
Rebecca Funston
Director of Regulatory Affairs and Quality Assurance
Cynon Valley Business Park Mountain Ash. CF45 4ER.
Rhondda Cynon Taf, Wales CF45 4ER
United Kingdom

Re: K251448
Trade/Device Name: FL-10000U Respiratory Humidifier
Regulation Number: 21 CFR 868.5450
Regulation Name: Respiratory Gas Humidifier
Regulatory Class: Class II
Product Code: BTT
Dated: May 9, 2025
Received: December 11, 2025

Dear Rebecca Funston:

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device"

U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

{1}

K251448 - Rebecca Funston
Page 2

(https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

{2}

K251448 - Rebecca Funston
Page 3

Sincerely,

Ethan L. Nyberg -S

Ethan Nyberg, Ph.D.
Assistant Director, Respiratory Devices Team
DHT1C: Division of Sleep Disordered Breathing, Respiratory and Anesthesia Devices
OHT1: Office of Ophthalmic, Anesthesia, Respiratory, ENT and Dental Devices
Office of Product Evaluation and Quality
Center for Devices and Radiological Health

Enclosure

{3}

FORM FDA 3881 (8/23)
Page 1 of 1
PSC Publishing Services [phone]
EF

| DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Indications for Use | Form Approved: OMB No. 0910-0120 Expiration Date: 07/31/2026 See PRA Statement below. |
| --- | --- |
| 510(k) Number (if known) K251448 | |
| Device Name FL-10000U Respiratory Humidifier | |
| Indications for Use (Describe) The Flexicare FL-10000U Respiratory Humidifier is intended to warm and add humidity to gases delivered to patients requiring mechanical ventilation or positive pressure breathing assistance via an endotracheal tube or face mask. For use by trained personnel only within a hospital/institutional environment. This device is intended to be used with the Flexicare Autofill Humidification Chamber and Flexicare Heated Wire Breathing Circuit. | |
| Type of Use (Select one or both, as applicable) ☑ Prescription Use (Part 21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C) | |
| CONTINUE ON A SEPARATE PAGE IF NEEDED. | |
| This section applies only to requirements of the Paperwork Reduction Act of 1995. *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* | |
| The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff [e-mail] | |
| "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." | |

{4}

510(k) Number: K251448

# 510(k) Summary

# (K251448)

Prepared in accordance with the requirements of 21 CFR Part 807.92

Prepared Date: 2026/01/15

# 1. Submission sponsor

Name: Flexicare Medical Limited

Address: Cynon Valley Business Park Mountain Ash. CF45 4ER. United Kingdom

Contact person: Rebecca Funston

Title: Director of Regulatory Affairs and Quality Assurance

Tel: [phone]

# 2. Subject Device Information

| Trade/Device Name | FL-10000U Respiratory Humidifier |
| --- | --- |
| Common Name | Respiratory Humidifier |
| Regulatory Class | Class II |
| Classification | 21 CFR 868.5450 / Respiratory Gas Humidifier / BTT |
| Product code | BTT |
| Submission type | Traditional 510(K) |

# 3. Predicate Device

| No. | Device name and model | 510(K) number | Manufacturer |
| --- | --- | --- | --- |
| Predicate device | Flexicare FL-9000U Respiratory Humidifier Base | K161314 | Flexicare Medical Limited |

# 4. Device Description

FL-10000U is an electrically powered Respiratory Humidifier that actively conditions the inspired respiratory gases delivered to ventilated patients and those receiving respiratory support. It is used as part of a complete system including a Humidification Chamber and either a heated wire breathing system.

FL-10000U Respiratory Humidifier is used with patients who require mechanical ventilation or positive pressure breathing assistance via an endotracheal tube and/or face mask.

The heater plate warms the water in the Humidification Chamber installed on to the top of the device. Gases are warmed and gain humidity in the form of water vapor as they travel along the breathing circuit on the to the patient.

# 5. Intended use & Indication for use

{5}

510(k) Number: K251448

The Flexicare FL-10000U Respiratory Humidifier is intended to warm and add humidity to gases delivered to patients requiring mechanical ventilation or positive pressure breathing assistance via an endotracheal tube or face mask. For use by trained personnel only within a hospital/institutional environment. This device is intended to be used with the Flexicare Autofill Humidification Chamber and Flexicare Heated Wire Breathing Circuit.

# 6. Comparison to the Predicate Device

Table 1: Subject device FL-10000U Respiratory Humidifier Base and Predicate Comparison Table

| | Subject Device FL-10000U Respiratory Humidifier Base | Flexicare's FL-9000U Respiratory Humidifier Base | Comparison |
| --- | --- | --- | --- |
| 510(k) | Unknown | K161314 | - |
| Indications for use | The Flexicare FL-10000U Respiratory Humidifier Base is intended to warm and add humidity to gases delivered to patients requiring mechanical ventilation or positive pressure breathing assistance via an endotracheal tube or face mask. For use by trained personnel only within a hospital/institutional environment. This device is intended to be used with the Flexicare Autofill Humidification Chamber and Flexicare Heated Wire Breathing Circuit. | The Flexicare FL-9000U Respiratory Humidifier Base is intended to warm and add humidity to gases delivered to patients requiring mechanical ventilation or positive pressure breathing assistance via an endotracheal tube or face mask. For use by trained personnel only within a hospital/institutional environment. This device is intended to be used only with the Flexicare Heated Wire Breathing System and Flexicare Autofill Humidification Chamber. | Same |
| Product Code | BTT | BTT | Same |
| Regulation No. | 21 CFR 868.5450 | 21 CFR 868.5450 | Same |
| Classification | Class II | Class II | Same |
| Supplied/Use | Re-usable | Re-usable | Same |
| Principle of operation | The device has two heating control units and two | The device has two heating control units and | Same |

{6}

510(k) Number: K251448

| | temperature sensors respectively. Water within a humidification chamber is heated by the device's heating plate and this temperature is controlled by the device with the use of temperature probes. Dry medical gases passing through the chamber gain increased humidity and heat.
The supplied Heated wire adaptors supply current to heated wires within breathing tubes that maintain gas temperature travelling to patient. Temperature probes measurement temperature and device controls chamber temperature to achieve desired gas warmth and humidify for patient. | two temperature sensors respectively. Water within a humidification chamber is heated by the device's heating plate and this temperature is controlled by the device with the use of temperature probes. Dry medical gases passing through the chamber gain increased humidity and heat.
The supplied Heated wire adaptors supply current to heated wires within breathing tubes that maintain gas temperature travelling to patient. Temperature probes measurement temperature and device controls chamber temperature to achieve desired gas warmth and humidify for patient. | |
| --- | --- | --- | --- |
| Structure and operation | The product consists of FL-10000U Respiratory Humidifier, Heated wire adaptor leads (single & dual) and Temperature sensor leads. | The product consists of FL9000U Respiratory humidifier, Heated wire adaptor leads (single & dual) and Temperature sensor leads. | Same |
| Mode of operation | Device does not have patient contact. During use it is located between the ventilator and breathing system (between ventilator and patient). | Device does not have patient contact. During use it is located between the ventilator and breathing system (between ventilator and patient). | Same |
| Scope of patient | Device intended for patients requiring mechanical ventilation, | Device intended for patients requiring mechanical ventilation, | Same |

3 / 7

{7}

510(k) Number: K251448

| | positive pressure breathing support or other respiratory support requiring controlled heat and humidity | positive pressure breathing support or other respiratory support requiring controlled heat and humidity | |
| --- | --- | --- | --- |
| Electric lightning protection | Class I | Class I | Same |
| Applied part | Type B | Type B | Same |
| Drip proof | IPX 1 | IPX 1 | Same |
| Target population | Any patient requiring active humidification | Any patient requiring active humidification | Same |
| Housing material | Polycarbonate | Polycarbonate | Same |
| Temp sensing | YSI | YSI | Same |
| Heating Method | Pass over | Pass over | Same |
| Heated Wire control on/off | Yes | Yes | Same |
| Single/dual/non heated wire compatible | Yes | Yes | Same |
| Dimensions | 156mm × 170mm × 130mm | 156mm × 170mm × 130mm | Same |
| Weight | 2.9kg | 2.9kg | Same |
| Supply frequency | 50/60 Hz | 50/60 Hz | Same |
| Supply voltage | 115V~ | 115V~ | Same |
| Supply current | 2.0 A max at 115V~ | 2.0 A max at 115V~ | Same |
| Heater plate | 150 W | 150 W | Same |
| Heater plate over temperature cutout | 115 ± 3°C | 115 ± 3°C | Same |
| Safety cutoff software | 110°C | 110°C | Same |
| Heater Wire | 22V~, 2.73A, 60W, 50/60Hz | 22V~, 2.73A, 60W, 50/60Hz | Same |
| Temperature control settings (heater wire) | | | |

{8}

510(k) Number: K251448

| Airway | Invasive: Default: 40°C, Range: 38-40°C
Non-invasive: Default: 34°C, Range: 31-34°C | Invasive: Default: 40°C, Range: 36-40°C
Non-invasive: Default: 34°C, Range: 31-35°C | Similar |
| --- | --- | --- | --- |
| Chamber outlet | Invasive: Default:37°C, Range: 35-37°C
Non-invasive: Default: 31°C, Range: 30-34°C | Invasive: Default: 37°C Range: 34-40°C
Non-invasive: Default: 31°C Range: 31-35°C | Similar |
| Alarm Parameters | | | |
| | High Humidity Alarm | | |
| Alarm parameter | Airway: High alarm
Chamber: High alarm / Low alarm | Airway: High alarm / Low alarm
Chamber: High alarm / Low alarm | Similar |
| Display temperature of 41°C | Yes | Yes | Same |
| Airway Temperature exceeds 43°C | Yes | Yes | Same |
| | Low Humidity Alarm | | |
| 60 minutes @ 34.5 °C | Yes | Yes | Same |
| 10 minutes @ 29.5 °C | Yes | Yes | Same |
| Sound Pressure Level | Alarms exceed 50 dBA @ 1m | Alarms exceed 50 dBA @ 1m | Same |
| Performance | | | |
| Recommended ambient Temperature range | 18 - 26°C | 18 - 26°C | Same |
| Recommended Flow range | Invasive: Min 1.5 lpm at a PEEP ≥ 3 cmH₂O
Non-Invasive: Max 60 lpm | Invasive: Up to 60 L/min
Non-invasive: Up to 120 L/min | Different |
| Humidity | Invasive: >33mg/L | Invasive: >33mg/L | Same |

{9}

510(k) Number: K251448

| performance | Non-invasive: >10mg/L | Non-invasive: >10mg/L | |
| --- | --- | --- | --- |
| Warm-up time | Less than 30 minutes | Less than 30 minutes | Same |
| Standard and Approvals | IEC 60601-1 | EN 60601-1 | Equivalent, ISO 8185 is replaced by newest version ISO 80607-2-74 |
| | IEC 60601-1-2 | EN 60601-1-2 | |
| | ISO 80601-2-74 | EN ISO 8185 | |
| | ISO 10993-1 | EN ISO 10993-1,3,5,6,10 | |
| | IEC 62366-1 | EN 62366 | |
| | IEC 62304 | EN 62304 | |
| | ISO 3744 | ISO 3744 | |
| | IEC 60529 | BS EN 60529 | |

## 7. Non-clinical Data

The following performance data were provided in support of the substantial equivalence determination.

## Biocompatibility testing

Biocompatibility of the subject device was evaluated in accordance with the FDA guidance “Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process" and International Standard ISO 10993-1 “Biological Evaluation of Medical Devices – Part 1: Evaluation and Testing Within a Risk Management Process,” and ISO 18562-1”. Biocompatibility evaluation of breathing gas pathways in healthcare applications - Part 1: Evaluation and testing within a risk management process” as recognized by FDA, FDA's guidance document on Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process",2023. Testing of the subject device demonstrates an appropriate biocompatibility profile for the device.

## Electrical safety, electromagnetic compatibility (EMC) and Alarms

Electrical safety and EMC testing were conducted on the subject device. The system complies with the ANSI AAMI ES60601-1:2005/(R)2012 & A1:2012, C1:2009/(R)2012 & A2:2010/(R)2012 (Cons. Text) [Incl. AMD2:2021] for safety and the IEC 60601-1-2:2014 + AMD1:2020 Ed 4.1 for EMC. Alarms testing was performed in accordance with IEC 60601-1-8:2006+AMD1:2012+AMD2:2020.

## Bench performance testing

Performance testing was conducted to demonstrate substantial equivalence including:

- ISO 80601-2-74 Second edition 2021-07 Medical electrical equipment - Part 2-74:

{10}

510(k) Number: K251448

Particular requirements for basic safety and essential performance of respiratory humidifying equipment

## 8. Clinical study

Not applicable.

## 9. Conclusion

Performance testing and compliance with voluntary standards demonstrate that the subject device is substantially equivalent to the predicate device.