ISO 3500:2005规定了货船、客船、打捞船、重型起重船、拖船组合和海上钻井和生产平台的固定消防装置中使用的无缝钢制CO2气瓶的主要外部尺寸、附件、填充比和标记，其中任何一个都可以在港口或干船坞进行维修，以促进此类气瓶的互换性。

ISO 3500:2005 specifies the principal external dimensions, accessories, filling ratio, and marking for seamless steel CO₂ cylinders used in fixed fire-fighting installations on cargo ships, passenger ships, salvage vessels, heavy-lift vessels, tug-barge combinations and offshore drilling and production platforms, any of which can be serviced in port or in dry dock, in order to facilitate the interchangeability of such cylinders.