This depends on the role.
Personnel carrying out front-line security controls, such as the screening or guarding of cargo, are designated as SIA-licensable and are therefore subject to a CRC in order for the exemption to apply.
Staff undertaking, for example, administrative, clerical or IT roles, or who may simply have access to secure areas of a warehouse where known screened cargo or other supplies are stored, while conducting other non-front-line roles, are not deemed to be SIA licensable.
The activity of an individual 'handling' air cargo or other supplies who performs no security function (e.g. simply moving cargo or supplies from one area to another) would similarly be deemed not to be SIA licensable. In respect of both these examples of non-SIA licensable activity, a CRC is not required.