Babies are particularly vulnerable to second-hand smoke because their airways and immune systems are still developing and they also have increased exposure to harmful toxins in the smoking residue on clothes, furniture and other materials.  This means that infants who live in a home with smokers are at an increased risk of early death and diseases, including sudden unexpected death in infancy. This indicator tracks the proportion of infants living in a smoke-free home at the time of their nine to 12 month development check by a Health Visitor.

In 2020, 76% of children assessed were living in a smoke free home. This was only the third full year in which this data was collected.