True.
In the upper layers of the atmosphere, it blocks UV radiation from the sun; however, in the lower layers, it is a pollutant.
For the answer to the question above, the best part to place the breastplate to restraint an infant especially on cars in the armpit level. If you place it below. They might have a difficulty in breathing. Higher than armi. they might choke their neck. So the best place is in the Armpit level.
