An item that is releasing a mix of particulates and aerosols as well as gases is referred to as:

The correct terminology to describe an item that is releasing a mix of particulates, aerosols, and gases is "off-gassing." Off-gassing refers specifically to the process where substances release gas or vapor particles, which can occur from various materials such as plastics, paints, and building materials. This phenomenon is of particular concern in safety and health contexts, as it can introduce harmful chemicals into the air, which may pose respiratory risks or other health issues.

The term does encompass the release of particulates and aerosols, but it is most commonly recognized in relation to the emission of volatile organic compounds (VOCs) and gases. Understanding this process is essential for safety officers, especially in environments where air quality is critical. Thus, knowing about off-gassing can help in assessing and mitigating health risks associated with exposure to these materials.