A non-vented seal closes the hole completely — which is exactly why whoever puts it on has to keep watching the breathing and be ready to burp it.
At a glance
12 things to know about the non-vented HyFin
What fully occlusive means, where it sits in the TCCC Guidelines, and why it changes what you do after it goes on.
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01
Fully occlusive — no vent
The HyFin Chest Seal is a completely occlusive, self-adhesive dressing for an open chest wound from a gunshot, stab or other penetrating injury.3 With no vent, nothing passes through the dressing in either direction — air cannot be sucked in through the hole, and air building up inside cannot get out on its own.
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02
Not the HyFin Vent
North American Rescue makes two different HyFin seals: this non-vented one (item 10-0015) and the HyFin Vent, which has three venting channels (10-0029 single, 10-0037 twin pack).3 They share the 6 × 6 in. footprint but are separate products with separate NSNs.
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03
Where the TCCC Guidelines put it
Every open or sucking chest wound gets a vented chest seal immediately; if a vented seal is not available, a non-vented seal is used, and the casualty is monitored for a developing tension pneumothorax.1 A non-vented seal is the right tool when it is the seal you have.
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04
Why vented became first choice
In 8 pigs with an open chest wound and air added to the chest to mimic a leaking lung, a non-vented HALO seal and a vented Bolin seal both restored breathing at first; as air kept building, the non-vented seal led to tension pneumothorax in every animal at about 1.4 L, while the vented seal held to 2 L.8 That study moved the TCCC Guidelines to vented-first in 2013.7
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05
Burping is the safety valve
Because a non-vented seal cannot let air out, burping is how trapped air escapes: lift an edge with the red tab, let the air out, press it back down — or remove the seal. If breathing still worsens, trained providers decompress.1,4
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06
The oversized red tab
The large red elliptical tab peels the backing for single-step peel-and-adhere application, and it is the handle that makes burping possible with gloves on.3
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07
Transparent and conforming
The clear 6 × 6 in. dressing lets you place it directly over the wound and see it afterward, and it conforms to the curve of the chest.3
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08
You can write on it
North American Rescue designs the seal so it can be written on for treatment documentation — the time it went on, for example — when there is no casualty card to hand.3
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09
Adhesive for bad conditions
North American Rescue uses an enhanced adhesive gel formulated for casualties covered in blood, sweat, body hair or dirt.3 Wipe the skin around the wound first anyway: no adhesive grips well through a film of blood.
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10
Non-vented seals are still widely carried
In a registry of 62 casualties with gunshot or puncture wounds to the chest in Afghanistan, 2013–2014, most chest seals placed were not vented, even after the guideline changed.10 If a non-vented seal is what is in the kit, know how to watch for tension and how to burp it.
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11
A second job
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
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12
Registration and supply data
The FDA lists it as an occlusive wound dressing (product code NAD) — FDA-registered, Class I (510(k)-exempt) — labeled single use and not made with natural rubber latex.5 NSN 6510-01-532-8019 describes it as an occlusive HyFin chest seal, 6 × 6 in., issued each.6 North American Rescue states it is made in America.3
How to apply the non-vented HyFin
The sequence from the TCCC Guidelines and North American Rescue's demonstration — with the monitoring a non-vented seal demands.
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1Bleeding 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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2Find 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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3Wipe the skin. Wipe blood, sweat and debris from around the wound so the adhesive can grip.4 The seal goes on bare skin, never over clothing.
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4Peel 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 Write the time on the seal if you have a marker.3
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5Seal every hole. Cover the exit wound or any other hole in the chest wall — with a vented seal if you have one.1
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6Position 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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7Watch the breathing closely. Increasing respiratory distress, falling oxygen saturation or shock means a suspected 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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8Evacuate and keep checking. A penetrating chest wound can hide internal bleeding — move the casualty toward care early and keep reassessing the seal and the breathing.4
Where it fits
- An open or sucking chest wound when no vented seal is available1
- A second or third hole once the vented seals in the kit are used
- Holding a water-impermeable covering over eviscerated bowel1
- Kits built to an NSN that calls for the occlusive HyFin6
- First choice when a vented seal is at hand — the Guidelines put vented first1
- 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
- Casualties on positive-pressure ventilation — NAEMSP advises chest seals may be harmful there11
- Practice — train with a trainer seal and keep live seals for casualties
The evidence
The studies behind the vented-first rule and the place of non-vented seals — each row names the seals actually tested.
| 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 | HALO (non-vented) vs Bolin (vented) on an open chest wound, 8 pigs, serial air injections into the chest | Both restored breathing; non-vented seal led to tension pneumothorax in all pigs at about 1.4 L; vented seal held to 2 L |
| Kuhlwilm, J Spec Oper Med 2021 | Expert review | Four swine chest seal studies and eight international guidelines | Vented and non-vented seals both stabilized breathing; only vented seals did better at preventing tension; two civilian guidelines did not prefer vented |
| 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. None of the animal studies tested the non-vented HyFin by name; they compare non-vented and vented seals as classes.
How it compares
The non-vented HyFin beside the HyFin Vent formats and the combo pack that carries one of each.
| HyFin® (non-vented) | HyFin® Vent — Individual | HyFin® Vent Twin Pack | HyFin® Combo Pack | |
|---|---|---|---|---|
| Seals per pack | 1 | 1 | 2 | 2 — 1 vented + 1 non-vented |
| Seal size (excluding tab) | 6 × 6 in. | 6 × 6 in. | 6 × 6 in. | 6 × 6 in. each |
| Vent | None — fully occlusive | 3 laminar channels | 3 laminar channels | On the vented seal only |
| Packaged | 4.625 × 7.5 × 0.1 in. | 4.625 × 7.5 × 0.1 in. | 7.5 × 4.5 × 0.25 in. folded | 7.5 × 4.5 × 0.25 in. folded |
| Weight | 1.44 oz | 1.37 oz | 2.5 oz | 2.5 oz |
| NAR item · NSN | 10-0015 · 6510-01-532-8019 | 10-0029 · 6510-01-624-0840 | 10-0037 · 6510-01-642-6212 | 10-0073 · 6510-01-654-6787 |
| TCCC position | When no vented seal is available | First choice — vented | First choice — vented | Vented seal first; non-vented as the backup |
All dimensions, weights, item numbers and NSNs from North American Rescue.3,12 The TCCC position row reflects the Guidelines' Respiration/Breathing section.1
Build the system
The vented seals that come first, the combo pack, the other three jobs in the kit — tourniquet, packing gauze, pressure dressing — and a trainer.
Questions buyers ask
Package & specifications
Specifications coming soon. Contact us for detailed product information.
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