ISO 3449:2004规定了用于测量ISO 6165中定义的地面移动机械上使用的坠落物保护结构（FOP）的结构特性的实验室试验，并在代表性试验中给出了性能要求。它既适用于作为机器组成部分提供的FOP，也适用于为连接机器而单独提供的FOP。本规范不适用于填埋压实机、挖掘机、压路机、挖沟机、铺管机上使用的FOP，也不适用于附件（例如附件反铲）操作的附加底座，或额定功率小于15 kW的机器上使用的FOP。

ISO 3449:2004 specifies laboratory tests for measuring the structural characteristics of, and gives performance requirements in a representative test for, falling-object protective structures (FOPS) intended for use on ride-on earth-moving machines as defined in ISO 6165. It is applicable to both FOPS supplied as an integral part of the machine and those supplied separately for attachment to the machine. It is not applicable to FOPS intended for use on landfill compactors, excavators, rollers, trenchers, pipelayers, for the additional seat for operation of an attachment (e.g. attachment backhoe), or on machines with a power rating of less than 15 kW.