1·Among the more than 7,000 chemicals that have been identified in secondhand tobacco smoke, at least 250 are known to be harmful, for example, hydrogen cyanide, carbon monoxide, and ammonia.
已确定二手烟的烟雾中含有超过7千种化学物质，其中至少250种是有害的，比如氰化氢、一氧化碳和氨。
2·It also protects against carbon monoxide, smoke, hydrogen cyanide, sulfur dioxide, other gases, particulates, fumes, soot, ammonia, chlorine, phosphine, and radiant heat.
它还可以防止一氧化碳，烟雾，氰化氢，二氧化硫，其他气体，颗粒，烟雾，烟尘，氨，氯，磷，和辐射热的危害。