asphyxiant

as.phyx.i.ant

adj.（形容词）
Inducing or tending to induce asphyxia.
窒息性的：导致或有可能导致窒息
n.（名词）
A substance, such as a toxic gas, or an event, such as drowning, that induces asphyxia.
窒息剂，窒息原因：导致窒息的物质，如有毒气体，或一事件，如溺水