Ethylene is a group of plant growth regulators that are widely used for the purpose of ripening fruits and for the production of more flowers and fruits.
The ethylene found in plant acts as a growth regulator, even in trace amount throughout entire plant life by regulating and stimulating the opening of flowers, fruit ripening and shedding of leaves.
Yes, ethylene is an asphyxiant, and is capable of causing death by suffocation (asphyxiation).
However, this happens only if the individual is in an enclosed space and the concentration of the ethylene is very high.