top of page
Baby Safety Month Final.png


What is the difference between Suffocation and Asphyxia?


a. Face occlusion

Different infants develop the ability to roll at different ages. Infants learn to roll from back to front before they are able to roll from front onto their back. Therefore, an infant who rolls onto their stomach may not be able to roll back. If sleeping face down (prone), they are more likely to occlude their mouth and nose if the surface is soft and compressible and does not allow the free movement of inhaled and exhaled air or they are unable to use their arms to push away from the surface (some swaddling products).

Loose items placed within (pillows, bedding, sleep positioners, decorations or toys) or pulled into the sleep environment (nappy bags) can also cause face occlusion.


‘Breathability’ ( air permeability) of fabric or surfaces is a confusing term and requires further definition and restriction. It is currently commonly used to refer to wicking capacity for material used in sports clothing. It has deliberately not been used here.


Face occlusion is described in ISO Guide 50; 7.5.2 Suffocation Hazards; flexible materials.

b. Airway occlusion

Airway occlusion can occur through internal obstruction (foreign body) or external compression.
Airway obstruction due to foreign bodies is described in ISO Guide 50; 7.7.1, Small objects and suction hazards; small objects.

Chin to chest:
Even when lying on a flat surface, an infant’s head tends to tip forward because of their protruding occiput (back of the head). A surface that is curved (C-sling, soft-based hammock), has padding behind the head (car restraint) or one where the infant can settle into the surface (waterbed, bean bag) creates a situation where the infant’s chin can be pushed towards the chest. This can cause relative airway compression that subtly increases the work required for an infant to breath.

c. Chest/ abdominal compression

Infants can suffocate if exposed to products (weighted blankets, tight swaddling) that restrict their chest wall/ abdominal movement or if caught in a device that inadvertently closes (collapsed porta cot) around the infant’s chest or abdomen.

Risk associated with chest/ abdominal compression/ entrapment is not specifically described in ISO Guide 50.

d. Airway occlusion with chest/ abdominal compression

Tucked position:
In addition to the hazard of chin to chest positioning, products with a curved surface (C-slings, soft-based hammocks) or one in which the child can settle (bean bags, waterbeds) also cause the child to be in a tucked position with a curved back. This compounds the effect of airway compression by further compromising respiratory efforts through increasing intra-abdominal pressure and reducing the downward diaphragm movement required for breathing.


Seated/ inclined devices:
Products where the infant sleeps inclined (inclined sleepers) even where the head is not pushed forward by the structure, promote external airway occlusion and respiratory compromise through the head falling forwards and the infant slouching in the device. Such devices also promote premature rolling and therefore increase the risk of suffocation.


Chin to chest, tucked and seated/ inclined positioning are described in ISO Guide 50; 7.5.5 as Suffocation hazards; positional asphyxia’.

Asphyxia: (suffocation with reduced cerebral blood flow)

a. Strangulation

Strangulation occurs when a product tightens or wraps around an infant’s neck and causes both airway obstruction and reduced blood flow to the brain. The reduced blood flow rapidly causes unconsciousness. Items that cause strangulation can either be worn (necklaces, clothing pulls/ties/ cuffs) or be inherent to (straps), placed within (mosquito netting, monitor cords) or pulled into (blind cords) the sleep environment.

Strangulation can occur either because the infant’s movement results in the product wrapping around the neck (necklace or clothing drawstring), or because the product tightens or retracts (elastic/ flexible strings, retractable drawstrings) or because the product snags on a fixture (cuffs). Sometimes a combination of these events is required.

b. Head entrapment

An infant’s head is wider than their body (measured front to back). Therefore, it is possible for an infant to pass their body through a gap but be caught at the head. Where the infant is unable to support their weight other than by the head, this can cause respiratory compromise even where there is no direct airway or vascular compression.

Head entrapment can also result from a device that inadvertently closes (collapsed porta cot) around the infant’s neck.

c. Hanging

Hanging involves either strangulation from a suspended fixture (mosquito netting, blind cord) or snagging/ entrapment (hoodie or cuff caught on a fixture, toggle on hat cord wedged in a small opening or infant’s head caught in a gap) and usually occurs when an infant is old enough to pull themselves to standing and/ or attempt to climb out of the sleep environment.

Strangulation hazards are described in ISO Guide 50; 7.6; Strangulation hazards
Entrapment hazards are described in ISO Guide 50; 7.2.1; Gaps and openings
Snagging hazards are described in ISO Guide 50; 7.2.2; protrusions and projections

Baby Safety Themes

Sleep Safety

Preparing for

Car Restraints

Safety Around the House

bottom of page