HyFin® by North American Rescue · Vented Chest Seal
HyFin® Vent Chest Seal — Twin Pack
Two 6 × 6 in. vented chest seals, each sealed in its own foil pouch with a gauze pad for wiping the skin, joined in one perforated twin pack — one seal for the entry wound, one for the exit. Three adhesive-free channels let air and blood escape from the chest while the film lies flat against the skin when the casualty breathes in. A vented chest seal is the TCCC Guidelines' first choice for an open or sucking chest wound.
Vented — 3 channels2 seals · 6 × 6 in.Gauze prep pad with each sealPerforated twin pouchNSN 6510-01-642-6212
Two holes, two seals — and the job is not finished when the seal is on. Watch the breathing until someone takes the casualty from you.
The short answer
What it is
Two vented HyFin chest seals, 6 × 6 in. each, individually foil-packed with a gauze prep pad, in one perforated twin pack (North American Rescue item 10-0037).
Use it for
Open or sucking chest wounds from gunshots, stabs or fragments — one seal on the entry wound, the second on the exit wound or a second hole.
How it's used
Wipe the skin with the pad, peel by the red tab, center the seal over the hole and press the edges down. Then watch breathing — if it gets worse, burp or remove the seal.
Who carries it
Military, law enforcement and EMS carry it in the IFAK or aid bag; trained civilians carry it beside the tourniquet, packing gauze and pressure dressing.
At a glance
Seal size
6 × 6 in. (excluding tab)
Prep pad
1 gauze pad per seal
Packaged
7.5 × 4.5 × 0.25 in. folded
FDA
Class I, 510(k)-exempt
Latex
Not made with natural rubber latex
12 things to know about the HyFin Vent Twin Pack
How the vent works, where the TCCC Guidelines put it, and what the swine studies found for the HyFin and its competitors.
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01
Two seals, opened one at a time
Each seal sits in its own foil pouch with Red-Tip Technology® tear notches, and the two pouches are joined by a perforation — tear off one, apply it, and the second stays sealed for the exit wound or the next casualty.3 A gunshot that goes through the chest leaves two holes; a pack with one seal leaves one of them open.
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02
How the vent works
The vent is not a valve. There is no adhesive over a central area above the wound or along channels that run to the edge of the seal: when pressure in the chest rises, air and blood move out along the channels; when the casualty breathes in, the film collapses against the skin and blocks air from entering.3,7
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03
Three channels, one fail-safe
North American Rescue designs the three channels so that blood can escape as well as air, and states the vent is designed to stay fully operational even if two of the three channels become obstructed.3
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04
Vented first — non-vented if that is all you have
The TCCC Guidelines direct that every open or sucking chest wound gets a vented chest seal immediately; if no vented seal is available, a non-vented seal is used, and the casualty is monitored for a developing tension pneumothorax.1 The vented-first wording entered the Guidelines in 2013.8 Practice lagged: in a 2013–2014 Afghanistan registry, most chest seals placed were still non-vented.14
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05
Why vented — the swine data
In 8 pigs with an open chest wound and air added to the chest to mimic a leaking lung, both a vented and an unvented seal restored breathing at first; as air kept building, the unvented seal led to tension pneumothorax in every animal at about 1.4 L, while the vented seal held up to 2 L. That study used the Bolin (vented) and HALO (unvented) seals.9
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06
The HyFin Vent in head-to-head tests
In 24 pigs, the HyFin, SAM and Sentinel vented seals (8 each) all evacuated air and blood, and no animal developed hemodynamic compromise with a seal in place.10 In a harder model — a bleeding chest wound in 26 pigs — the HyFin succeeded in 4 of 6 applications, against 6 of 6 for Sentinel and Russell, 1 of 4 for SAM and 0 of 4 for Bolin.12
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07
Channels beat one-way valves when the wound bleeds
In that bleeding-wound study, seals with laminar venting channels — HyFin, Sentinel, Russell — let blood and air out; seals with one-way valves either clogged with clot or were pushed off the skin by pooled blood.12 A 2021 systematic review of six quantitative studies reached a consensus recommendation for the HyFin Vent and the Russell seal, while noting how thin the evidence is.13
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08
Adhesion — what was measured
North American Rescue formulates the hydrogel adhesive for skin covered in blood, sweat, body hair or dirt.3 On live swine skin soiled with contaminants, the HyFin was one of five vented seals with comparable adherence at room temperature, and it kept that adherence after about 17 hours stored at −19.5 °C or 71.5 °C.11 Wiping the skin first still matters — that is what the gauze pad in each pouch is for.3,4
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09
A vent lowers the risk — it does not remove it
Any chest seal can fail: blood can pool under it, an edge can lift, a channel can clog.12 The Guidelines call for monitoring after every seal; increasing hypoxia, respiratory distress or falling blood pressure means burping or removing the dressing, or needle decompression by a trained provider.1
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10
The red tab does two jobs
The large red tab peels the backing in one step, and it is the handle you lift to burp the seal — open one edge, let trapped air out, press it back down.3,4 The transparent film lets you center the seal over the hole and see the wound under it.3
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11
Registration and supply data
The FDA lists the HyFin Vent as an occlusive wound dressing (product code NAD) — FDA-registered, Class I (510(k)-exempt) — labeled single use, not made with natural rubber latex, with a lot number and an expiration date on the label.5 The twin pack carries NSN 6510-01-642-6212, issued by the package.6
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12
Civilian use is a real debate
The National Association of EMS Physicians says EMS clinicians may consider a vented chest seal for an open chest wound in a casualty who is breathing on their own — and that in a casualty receiving positive-pressure ventilation, chest seals may be harmful and are not recommended.15 Know which situation you are in.
How to apply the HyFin Vent
The sequence from the TCCC Guidelines and North American Rescue's demonstration, in order.
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1
Bleeding first. Massive bleeding comes before the chest — tourniquet or packing first, then the open chest wound.1 Never pack a wound in the chest or abdomen.
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2
Find every hole. Expose the chest and look front, sides and up into the armpits, then roll the casualty and check the back — exit wounds are easy to miss.4 Cover the hole with a gloved hand while you tear the pouch open at the red notch.
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3
Wipe the skin. Use the gauze pad from the pouch to wipe blood, sweat and debris from around the wound so the adhesive can grip.3,4 The seal goes on bare skin, never over clothing.
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4
Peel and place. Pull the red tab to peel off the backing, center the seal over the hole and press it down firmly all the way around.3,4
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5
Seal the second hole. Tear off the second pouch and seal the exit wound or any other hole in the chest wall the same way.3
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6
Position the casualty. A conscious casualty can sit up or take whatever position makes breathing easiest; an unconscious casualty who is breathing goes in the recovery position.1
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7
Watch the breathing. If breathing gets harder, oxygen saturation falls or shock develops, suspect tension pneumothorax: burp the seal by lifting an edge with the red tab, or remove it. Trained providers then decompress the chest as the Guidelines direct.1,4
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8
Evacuate and keep checking. A penetrating chest wound can hide internal bleeding — move the casualty toward care early and keep reassessing the seals and the breathing.4
Train before you need it. North American Rescue makes a HyFin Chest Seal Trainer twin pack with a less aggressive adhesive designed for manikins and training partners — it is for practice, not for casualty care.16 Every live seal is single use; keep the ones in your kit sealed until a casualty needs them.5
Where it fits
Use it for
- Open or sucking chest wounds — gunshot, stab or fragment wounds through the chest wall1
- Entry and exit wounds on the same casualty — one seal each3
- Holes in the back and sides of the chest, found by rolling the casualty and checking the armpits4
- A casualty breathing on their own — the setting the NAEMSP statement addresses15
Not for
- Packing — never pack a wound in the chest or abdomen; the seal goes over the hole
- Treating a tension pneumothorax — burping, removal or needle decompression does that1
- Clothing, or skin still wet with blood and sweat — wipe first, apply to bare skin
- Casualties on positive-pressure ventilation — NAEMSP advises chest seals may be harmful there15
- Practice — train with a trainer seal and keep live seals for casualties
The evidence
Every study cited above, the seals it actually tested, and how strong the evidence is.
| Study |
Evidence type |
What was studied |
What it found |
| Schauer et al., J Spec Oper Med 2017 |
Human · combat registry |
62 casualties with gunshot or puncture wounds to the chest, Afghanistan, 2013–2014 |
74.2% received a chest seal; most seals placed were not vented, despite the 2013 guideline change |
| Kheirabadi et al., J Trauma Acute Care Surg 2013 |
Animal · swine |
Bolin (vented) vs HALO (unvented) on an open chest wound, 8 pigs, serial air injections into the chest |
Both restored breathing; unvented seal led to tension pneumothorax in all pigs at about 1.4 L; vented seal held to 2 L |
| Kotora et al., J Emerg Med 2013 |
Animal · swine |
HyFin vs SAM vs Sentinel vented seals, 8 pigs each, communicating pneumothorax with air and blood challenges |
All three evacuated air and blood; no hemodynamic compromise with any seal in place |
| Arnaud et al., Injury 2016 |
Animal · swine skin adhesion |
Vented seals on soiled live swine skin; five down-selected (Bolin, Russell, Fast Breathe, HyFin, SAM), then stored ~17 h at −19.5 °C and 71.5 °C |
Comparable adherence at room temperature; HyFin, Russell, Fast Breathe and SAM held after extreme storage, Bolin did not |
| Kheirabadi et al., J Trauma Acute Care Surg 2017 |
Animal · swine |
Five vented seals on a bleeding chest wound (hemopneumothorax), 26 pigs |
Success: Sentinel 6/6, Russell 6/6, HyFin 4/6, SAM 1/4, Bolin 0/4 (p = 0.002); one-way valves clogged or detached |
| Paquette et al., J Spec Oper Med 2021 |
Expert review · systematic |
Systematic review of quantitative chest seal studies, 1990–2020 (6 included) |
Consensus recommendation for the HyFin Vent and Russell seals; evidence on individual devices is limited |
| Lyng et al., Prehosp Emerg Care 2024 |
Expert review · NAEMSP position |
Structured review and position statement on EMS care of traumatic pneumothorax |
May consider a vented seal in spontaneously breathing patients; seals may be harmful with positive-pressure ventilation |
| Butler et al., J Spec Oper Med 2013 |
Expert review · guideline change |
TCCC Guidelines Change 13-02, management of open pneumothorax |
Vented chest seal first; non-vented if no vented seal is available; monitor and burp, remove or decompress |
Strongest to weakest: human data, then animal studies, then expert review. The product-specific data on the HyFin Vent come from swine studies; no human trial has compared chest seal brands.
How it compares
The HyFin family side by side — the same three-channel vent in three formats, and the non-vented seal.
|
HyFin® Vent Twin Pack |
HyFin® Vent — Individual |
HyFin® Vent Compact Twin |
HyFin® (non-vented) |
| Seals per pack |
2, each in its own foil pouch |
1 |
2, each in its own foil pouch |
1 |
| Seal size (excluding tab) |
6 × 6 in. |
6 × 6 in. |
4.75 × 4.75 in. |
6 × 6 in. |
| Vent |
3 laminar channels |
3 laminar channels |
3 channels |
None — fully occlusive |
| Packaged |
7.5 × 4.5 × 0.25 in. folded |
4.625 × 7.5 × 0.1 in. |
3.875 × 6.6 × 0.13 in. |
4.625 × 7.5 × 0.1 in. |
| Weight |
2.5 oz |
1.37 oz |
1.55 oz |
1.44 oz |
| NAR item · NSN |
10-0037 · 6510-01-642-6212 |
10-0029 · 6510-01-624-0840 |
10-0042 · 6510-01-682-2091 |
10-0015 · 6510-01-532-8019 |
| TCCC position |
First choice — vented |
First choice — vented |
First choice — vented |
When no vented seal is available |
All dimensions, weights, item numbers and NSNs from North American Rescue.3 The TCCC position row reflects the Guidelines' Respiration/Breathing section.1
Build the system
The rest of the chest system, the three other jobs in the kit — tourniquet, packing gauze, pressure dressing — and a trainer.
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Questions buyers ask
▾Is the HyFin Vent evidence-based standard?
No chest seal is named on the Evidence-Based Standard Devices & Adjuncts list (15 December 2021); its named products are tourniquets and hemostatic dressings, so the HyFin Vent is not evidence-based standard by name.2 What the TCCC Guidelines specify is the device class — a vented chest seal first for an open or sucking chest wound — and the HyFin Vent is a vented chest seal.1 Absence from the list does not by itself mean a product was tested and failed.
▾Vented or non-vented — which should I carry?
Vented. The Guidelines put a vented seal first and a non-vented seal second, for when no vented seal is available; either one is then watched for a developing tension pneumothorax.1 In swine, a non-vented seal let tension build when air kept leaking into the chest, while a vented seal let it escape.9
▾Why does the pack have two seals?
A bullet or blade that goes through the chest leaves an entry and an exit wound, and both need sealing. Each seal is packaged separately, so you can use one and keep the other sealed until it is needed.3
▾Does the vent prevent a tension pneumothorax?
It is designed to let air escape so pressure cannot build, and it did that in swine studies — but vented seals have also failed in testing when blood pooled or an edge lifted.3,10,12 Treat every sealed casualty as someone who can still develop a tension pneumothorax, and keep watching.
▾How do I burp a chest seal?
Lift one edge of the seal with the red tab, let trapped air escape, and press the seal back down. If breathing does not improve, remove the seal; trained providers then perform needle decompression as the Guidelines direct.1,4
▾Will it stick to a bloody, sweaty or hairy chest?
North American Rescue formulates the hydrogel for exactly those conditions,3 and on soiled swine skin the HyFin held as well as the other leading vented seals, even after extreme hot and cold storage.11 Adhesion still fails when the skin is not wiped, so use the gauze pad in the pouch and press every edge down.
▾What if I don't have a chest seal?
Most bystanders won't. Have the casualty press their own hand over the hole, or cover it the best way you can — improvising a seal is hard unless you have tape and something airtight, like a plastic wrapper. Keep watching their breathing. Let a conscious casualty sit up or find the position that is easiest to breathe in; put an unconscious casualty who is breathing in the recovery position.1
▾Should civilian responders use chest seals?
It is debated. NAEMSP says EMS clinicians may consider a vented seal for an open chest wound in a casualty breathing on their own, and advises against seals in casualties receiving positive-pressure ventilation.15 Military and tactical guidance calls for one immediately.1 Whoever applies it has to keep watching the breathing.
▾Is it sterile, and does it expire?
The FDA device record lists the HyFin Vent as single use and not labeled sterile, with a lot number and an expiration date printed on the label.5 Use a seal before its expiration date and never reuse one.
▾Can a chest seal do any other job?
Yes — the TCCC Guidelines name a chest seal as one of the adhesive dressings that can hold a water-impermeable covering over bowel that has come out of an abdominal wound.1
Package & specifications
▾In the package — two vented seals
- 2× HyFin® Vent Chest Seal, 6 × 6 in. (excluding tab), three-channel vent, transparent film, large red pull tab
- Each seal in its own foil pouch with Red-Tip Technology® tear notches and a gauze pad for wiping the skin
- Perforated twin foil pouch — open one seal at a time
- Single use, not labeled sterile. Needle decompression device and trainer sold separately.
▾Full specifications
| Specification |
Detail |
| Manufacturer |
North American Rescue, LLC |
| Product |
HyFin® Vent Chest Seal Twin Pack |
| NAR item |
10-0037 |
| NSN |
6510-01-642-6212 — Dressing, Chest Seal Wound; unit of issue: package |
| Contents |
2 vented chest seals, each individually foil-packaged with a gauze prep pad, in a perforated twin pouch |
| Seal size |
6 × 6 in. (excluding tab) |
| Vent |
Three laminar channels; designed to stay operational if two of the three are obstructed (manufacturer) |
| Adhesive |
Hydrogel, formulated for skin covered in blood, sweat, hair or contaminants (manufacturer) |
| Film / tab |
Transparent; large red tab for peel-and-apply and for burping |
| Packaged size |
Folded 7.5 × 4.5 × 0.25 in. · unfolded 7.5 × 9 × 0.13 in. |
| Weight |
2.5 oz (twin pack) |
| Patent |
U.S. 7,504,549 (North American Rescue, issued 2009) |
| FDA |
Occlusive wound dressing, product code NAD, 21 CFR 878.4020 — FDA-registered, Class I (510(k)-exempt) |
| Sterility / use |
Not labeled sterile; single use |
| Latex |
Not made with natural rubber latex (device labeling) |
| Label |
Lot number, manufacturing date and expiration date |
| TCCC status |
Vented chest seal — the TCCC Guidelines' first choice for an open or sucking chest wound; no chest seal is named on the Evidence-Based Standard Devices & Adjuncts list |
▾References — 16 sources
- Committee on Tactical Combat Casualty Care. Tactical Combat Casualty Care (TCCC) Guidelines, 1 May 2026.
- Committee on Tactical Combat Casualty Care. Evidence-Based Standard Devices & Adjuncts, 15 December 2021.
- North American Rescue. HyFin® chest seal product pages and product information sheets — HyFin® Vent Chest Seal Twin Pack 10-0037 (REV090622); HyFin® Vent Chest Seal – Individual 10-0029 (REV080224); HyFin® Vent Compact Chest Seal Twin Pack 10-0042 (REV090622); HyFin® Individual Occlusive Chest Seal 10-0015 (REV090622). narescue.com.
- North American Rescue. How Does a Chest Seal Work? NAR education blog and application demonstration. narescue.com.
- U.S. Food and Drug Administration / National Library of Medicine. AccessGUDID device records, North American Rescue, LLC, model 10-0037 — GMDN 46424 Pneumothorax dressing; FDA product code NAD (Dressing, Wound, Occlusive), 21 CFR 878.4020, Class I, premarket exempt.
- Defense Logistics Agency. Federal Logistics Information System record, NSN 6510-01-642-6212, Dressing, Chest Seal Wound (HyFin Vent twin pack; part number 10-0037).
- Castellani R, Miller R. Chest wound seal for preventing pneumothorax and including means for relieving a tension pneumothorax. U.S. Patent 7,504,549, issued 17 March 2009; assignee North American Rescue.
- Butler FK Jr, DuBose JJ, Otten EJ, et al. Management of open pneumothorax in Tactical Combat Casualty Care: TCCC Guidelines Change 13-02. J Spec Oper Med. 2013;13(3):81–86.
- Kheirabadi BS, Terrazas IB, Koller A, et al. Vented versus unvented chest seals for treatment of pneumothorax and prevention of tension pneumothorax in a swine model. J Trauma Acute Care Surg. 2013;75(1):150–156.
- Kotora JG Jr, Henao J, Littlejohn LF, Kircher S. Vented chest seals for prevention of tension pneumothorax in a communicating pneumothorax. J Emerg Med. 2013;45(5):686–694.
- Arnaud F, Maudlin-Jeronimo E, Higgins A, et al. Adherence evaluation of vented chest seals in a swine skin model. Injury. 2016;47(10):2097–2104.
- Kheirabadi BS, Terrazas IB, Miranda N, et al. Do vented chest seals differ in efficacy? An experimental evaluation using a swine hemopneumothorax model. J Trauma Acute Care Surg. 2017;83(1):182–189.
- Paquette R, Quinene M, Blackbourne LH, Allen PB. Efficacy of commercial chest seal adherence and tension pneumothorax prevention: a systematic review of quantitative studies. J Spec Oper Med. 2021;21(3):78–85.
- Schauer SG, April MD, Naylor JF, et al. Chest seal placement for penetrating chest wounds by prehospital ground forces in Afghanistan. J Spec Oper Med. 2017;17(3):85–89.
- Lyng JW, Ward C, Angelidis M, et al. Prehospital trauma compendium: traumatic pneumothorax care — position statement and resource document of NAEMSP. Prehosp Emerg Care. Published online 4 December 2024. doi:10.1080/10903127.2024.2416978.
- North American Rescue. HyFin® Chest Seal Twin Pack – Trainer, item 10-0032, product information sheet (REV090622). narescue.com.
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