Face Shields, Pocket Masks and Bag-Valve Masks for CPR

Rescue breaths remain an important part of cardiopulmonary resuscitation, particularly in situations involving children, drowning, hypoxia or respiratory arrest. Although mouth-to-mouth ventilation can be effective, many trained first aiders prefer to use a barrier or ventilation device when one is available. Barriers are particularly valuable when the first aider is concerned about giving CPR breaths, perhaps due to the casualty being covered in saliva, vomit or blood. Barrier devices reduce direct contact but do not 100% eliminate the risk of exposure to bodily fluids or infection. As explained below, some ventilation devices can also make rescue breaths easier to deliver effectively. The three devices most commonly encountered are:

• CPR face shield
• Pocket mask (face mask)
• Bag valve mask (BVM)

They all have the same basic purpose — getting air into the casualty’s lungs — but they differ significantly in the protection they provide, the skill required to use them and the situations for which they are best suited.

Current Resuscitation Council UK guidance continues to emphasise effective ventilation as part of basic life support. If rescue breaths are provided, each breath should contain only enough air to make the casualty’s chest begin to rise, avoiding excessive ventilation. This article assumes that you are familiar with current CPR protocols. If not, we recommend reading our guide to CPR procedures and AED use first.

CPR Face Shields

A CPR face shield is the simplest form of barrier device. It is normally a thin sheet of plastic containing a one-way valve or filter which is positioned over the casualty’s mouth.

Many are small enough to be folded into a keyring pouch. The purpose of the shield is primarily to create a barrier between the rescuer and casualty while allowing mouth-to-mouth ventilation.

How to Use a CPR Face Shield

• Place the shield over the casualty’s face with the valve positioned over the mouth.
• Open the airway using the head-tilt/chin-lift technique. If a spinal injury is suspected, minimise unnecessary neck movement, but do not allow concerns about spinal injury to prevent effective airway opening and ventilation.
• Pinch the casualty’s nose closed.
• Seal your mouth around the valve and give a rescue breath over approximately one second.
• Look for the chest to begin to rise.
• Allow the chest to fall before giving the second breath.

Advantages of a Face Shield

The major advantages are its simplicity and size.

A face shield is:

• extremely compact;
• inexpensive;
• simple to carry;
• quick to deploy;
• useful when no larger ventilation equipment is available.

This makes it particularly suitable for first aiders who want a barrier device that can remain permanently in a personal first aid pouch or lifejacket pocket.

Limitations of a Face Shield

A face shield does not provide the same physical separation between casualty and rescuer as a pocket mask (see below).

The rescuer’s face must still come very close to the casualty. Effective ventilation depends on obtaining a good seal around the mouth and maintaining an open airway. The rescuer’s hands may also come into contact with saliva, vomit or blood, creating a risk of contaminating the clean side of the face shield while delivering CPR. Most basic face shields also provide no practical means of attaching supplemental oxygen. For these reasons, Chieftain Training recommends carrying a pocket mask rather than a face shield whenever practical. A pocket mask generally provides a better seal and greater separation between rescuer and casualty. For appropriately trained rescue teams, a BVM may also be a suitable option.“

Pocket Masks

A pocket mask is a shaped resuscitation mask which fits over the casualty’s mouth and nose.

Unlike a simple face shield, it creates a physical air space between the casualty and rescuer.

Most modern resuscitation masks contain a one-way valve, and many include an inlet through which supplemental oxygen can be supplied.

Resuscitation Council UK equipment standards include a pocket mask with an oxygen port among airway and breathing equipment recommended for immediate availability in primary care settings.

How to Use a Pocket Mask

• Position yourself at the casualty’s head.
• Place the narrow end of the mask over the bridge of the nose and the wider end between the lower lip and chin.
• Maintain an open airway using head tilt and chin lift where appropriate.
• Hold the mask firmly against the casualty’s face to create an airtight seal. A commonly taught grip is the C-E technique: the thumb and index finger form a C around the mask, the remaining fingers lift the jaw towards the mask.
• Blow through the one-way valve for approximately one second.
• Give only enough air to make the chest begin to rise.

A pocket mask offers two practical advantages over a face shield. Firstly, there is no need to pinch the casualty’s nose because the mask covers both the mouth and nose. Secondly, the rescuer can create a seal against the casualty’s face using the mask’s flexible edge rather than relying on a direct mouth-to-mouth seal. However, maintaining an open airway and a secure mask seal remains essential.

Why Pocket Masks Are Useful

Pocket masks offer several practical advantages over basic face shields.

They provide:

• a far greater separation between rescuer and casualty;
• a more controlled seal;
• a one-way ventilation valve;
• potentially better control of the airway;
• the ability on many models to connect supplemental oxygen.

They are also reusable if cleaned and maintained in accordance with the manufacturer’s instructions.

For professional first aiders and watersports instructors, a pocket mask can therefore be a useful compromise between simple mouth-to-mouth ventilation and more advanced BVM ventilation. The pocket mask is contained within the Cat. C first aid kit carried onboard commercial vessels, it is also a compulsory item onboard safety boats at RYA dinghy, keelboat, multihull, winging, windsurf, PWC and powerboat training centres.

Pocket Masks and Oxygen

Some pocket masks have an oxygen connection. When supplemental oxygen is available and the rescuer is appropriately trained, oxygen can be supplied through the mask while rescue breaths are delivered. The precise oxygen concentration received by the casualty depends on factors including:

• oxygen flow;
• mask design;
• the quality of the seal;
• the effectiveness of the rescue breaths being delivered

Oxygen equipment should only be used by people who have received appropriate training and in accordance with organisational procedures.

Bag-Valve Masks (BVMs) for CPR

The bag-valve mask, usually abbreviated to BVM, provides positive-pressure ventilation without the rescuer placing their mouth close to the casualty.

It consists of three principal parts:

Bag → Valve → Mask

It is sometimes colloquially called an Ambu bag, although Ambu is actually a manufacturer’s trade name. The flexible self-inflating bag is squeezed by the rescuer, pushing air through a one-way valve and mask into the casualty’s lungs. Many BVM systems can also be connected to an oxygen supply and reservoir.

Resuscitation Council UK lists a self-inflating bag with reservoir and appropriate clear face masks among airway equipment that should be immediately available in acute clinical settings. BVMs are part of the Category B medical kits carried on board SOLAS vessels and coded workboats and yachts that operate more than 60 miles from a safe haven.

BVM Ventilation Requires Training

A bag-valve mask may look straightforward, but effective BVM ventilation is considerably more difficult than simply squeezing the bag.

Effective BVM ventilation depends on three things:

1. The airway must be open.

2. The mask must form an effective seal around the casualty’s face.

3. The correct volume of air must be delivered.

Failure in any one of these areas can result in inadequate ventilation. Excessive ventilation can also cause problems. The aim remains: one breath over approximately one second, producing visible chest rise.

Current Resuscitation Council UK adult advanced life support guidance specifically says to optimise airway patency and mask seal and, where necessary, use a two-person technique for bag-mask ventilation.

One-Person BVM Technique

When only one trained rescuer is available, one hand normally holds the mask to the casualty’s face while maintaining the airway.

The other hand squeezes the bag. The rescuer commonly uses the C-E grip:

C — Thumb and index finger hold the mask

E — Remaining fingers lift the mandible

One-person BVM ventilation is difficult and can result in an inadequate seal or ineffective ventilation. A two-person technique is preferred whenever appropriately trained rescuers are available.

Two-Person BVM Technique

The preferred technique when sufficient rescuers are available is usually a two-person bag-mask technique.

One rescuer concentrates entirely on:

• opening the airway;
• positioning the mask;
• holding the mask with both hands;
• lifting the jaw;
• maintaining the seal.

The second rescuer squeezes the ventilation bag.

Resuscitation Council UK’s 2025 education guidelines specifically recommend teaching two-person ventilation when using a self-inflating bag and mask. This separation of tasks generally allows a much better mask seal and more reliable ventilation.

How Hard Should You Squeeze a BVM?

A common mistake is squeezing the bag too hard or too quickly. The casualty does not need the entire contents of an adult ventilation bag forced into their lungs. Instead:

• Squeeze only enough to make the chest visibly rise.
• Deliver the breath over approximately one second.
• Allow the bag to re-inflate fully before delivering another breath.

Excessive ventilation may force air into the stomach as well as the lungs and can contribute to gastric inflation, regurgitation and aspiration. It can also interfere with the circulation generated by chest compressions. The goal is therefore effective ventilation, not maximum ventilation.

BVM and Supplemental Oxygen

A self-inflating BVM can work using ordinary atmospheric air. It does not need an oxygen cylinder to inflate. However, many BVMs can be connected to:

• supplemental oxygen;
• an oxygen reservoir.

The oxygen concentration delivered depends on the flow rate, reservoir arrangement, mask seal and effectiveness of ventilation. With the appropriate equipment, oxygen supply and technique, this can substantially increase the oxygen concentration delivered to the casualty. For drowning-related cardiac arrest, trained responders should use 100% oxygen when available, without delaying effective ventilation to obtain it. Oxygen administration should nevertheless be undertaken only by rescuers who are appropriately trained and authorised to use the equipment.

Face Shield vs Pocket Mask vs BVM

 

Device	Main advantage	Main limitation	Relevance
Face shield	Tiny, cheap and easy to carry.	Limited separation and seal control	Better than nothing
Pocket mask	Good barrier and improved mask seal	Requires some training and is larger	Mandatory onboard all coded vessels and RYA Safetyboats
Bag-valve mask	Allows ventilation without mouth-to-mouth and can be combined with oxygen. Far less tiring for the First Aider	Requires significantly more skill	Mandatory onboard Cat 1 yachts & workboats and all SOLAS ships

There is therefore no single device that is automatically appropriate for every rescuer. A lone member of the public carrying a keyring face shield has very different equipment requirements from a professional first aid team carrying oxygen, suction equipment and a BVM.

What training is available?

At Chieftain Training the following techniques are taught on the following courses (this may not be reflected at other training providers).

	Face Shield	Pocket Mask	BVM
RYA First Aid	✅	✅
16 Hour outdoor First Aid	✅	✅
HSE Emergency First Aid at Work	✅	✅
HSE First Aid at Work	✅	✅	✅
HSE First Aid at Work Refresher	✅	✅	✅
STCW Elementary First Aid	✅	✅
STCW Medical First Aid		✅	✅
STCW Medical Care		✅	✅
STCW Medical Care Update		✅	✅
Paediatric First Aid	✅	✅

Which Device Should I Use During CPR?

For trained rescue teams, a BVM can provide effective ventilation without the fatigue associated with repeated mouth-to-mask breaths. However, successful BVM ventilation requires skill, a secure mask seal and effective airway management. A two-person technique is preferred where possible.

For individual first aiders, a pocket mask is often a simpler and more practical option. Whatever device is chosen, rescuers should minimise interruptions to chest compressions and avoid delaying CPR while searching for or assembling equipment.

Drowning Makes Ventilation Particularly Important

For a casualty who has drowned, oxygen deprivation is usually central to the cardiac arrest. This makes effective rescue breaths particularly important. In drowning-related cardiac arrest, begin with five initial rescue breaths before continuing with the appropriate CPR sequence.

A face shield, pocket mask or BVM may therefore be especially valuable in a watersports or marine environment where drowning is a foreseeable emergency. The device does not change the fundamental objective: open the airway and deliver effective breaths that make the chest rise.

For trained teams with appropriate equipment, a pocket mask or BVM will make this ventilation easier and will provide greater separation between rescuer and casualty.

About the Author

Doug Innes BA (Hons) is the Principal of Chieftain Training. He is an RYA First Aid Instructor Trainer and a STCW Medical Care Assessor. He has extensive experience delivering maritime safety and first aid training to recreational sailors, professional mariners, yacht crews and watersports instructors.

Doug holds an MCA Master 200 Certificate of Competency and has a background in both commercial maritime operations and practical training. He teaches first aid, sea survival and maritime safety courses, with particular emphasis on emergency response in the marine environment.

Published: 3 October 2026

Technical references: This article has been reviewed against the Resuscitation Council UK 2025 Resuscitation Guidelines, which remain current in 2026.

CPR Face Shields, Pocket Masks and BVMs – Frequently Asked Questions (FAQs)

What is the difference between a CPR face shield and a pocket mask?

A CPR face shield is a thin, flexible barrier placed over the casualty’s mouth during rescue breaths. A pocket mask is a rigid or semi-rigid mask covering both the nose and mouth, usually incorporating a one-way valve. Both reduce direct contact between rescuer and casualty, but a pocket mask generally provides a better seal and greater separation from bodily fluids.

Is a pocket mask better than a CPR face shield?

Generally, yes. A pocket mask allows the rescuer to maintain a seal around the casualty’s nose and mouth without direct mouth-to-mouth contact. It is particularly useful for first aiders who may need to deliver repeated rescue breaths. However, both devices require correct technique, and neither eliminates the risk of infection.

What is a bag-valve mask (BVM)?

A bag-valve mask (BVM), sometimes called an Ambu bag, is a manually operated ventilation device consisting of a self-inflating bag, a one-way valve and a face mask. When the bag is squeezed, air is delivered into the casualty’s lungs without the rescuer having to blow into the mask. A BVM can also be connected to supplemental oxygen when suitable equipment is available.

Can one person use a bag-valve mask?

Yes, but effective one-person BVM ventilation is difficult, particularly when maintaining an open airway and a reliable mask seal. A two-person technique is preferred, with one trained rescuer using both hands to maintain the airway and mask seal while the second squeezes the bag. BVMs should be used by appropriately trained rescuers.

Can a pocket mask or BVM be connected to oxygen?

Some pocket masks have an oxygen inlet that allows supplemental oxygen to be delivered while the rescuer provides breaths. Most medical BVMs can also be connected to an oxygen supply, often with a reservoir to increase the oxygen concentration delivered. The effectiveness of oxygen delivery depends on the equipment, oxygen flow rate, mask seal and ventilation technique.

Should I use a face shield, pocket mask or BVM for CPR?

For an individual trained first aider, a pocket mask is often the most practical choice because it is portable and provides a good barrier for rescue breaths. A face shield is smaller and easier to carry but may be more difficult to use effectively. For appropriately trained rescue teams, a BVM can provide effective ventilation, especially with two rescuers. Do not delay CPR while searching for ventilation equipment.

Why are rescue breaths particularly important following drowning?

Drowning usually causes cardiac arrest through a lack of oxygen rather than a primary heart problem. Rescue breaths are therefore particularly important. If a drowning casualty is unresponsive and not breathing normally, trained rescuers should give five initial rescue breaths before continuing CPR using the appropriate compression-to-ventilation ratio. A pocket mask or BVM may help deliver these breaths effectively.

Do I need training to use a pocket mask or bag-valve mask?

Practical training is recommended for pocket masks and is essential before attempting BVM ventilation. First aid training teaches rescuers how to open the airway, establish a mask seal and recognise effective ventilation. BVM operation requires additional practical skills, particularly when ventilating a casualty with two rescuers. Relevant training is available through RYA and STCW first aid courses, although the precise equipment covered varies between courses.