The COA is committed to safe, reliable and sustainable container operations and engages with leading global flexitank manufacturers and operators to implement the COA Code of Practice and industry best practice.


A flexitank is a large bladder with valve(s) that is designed to fit inside a general-purpose freight container and operate as part of a system which includes the container, flexitank, its fittings and restraining system.

The flexitank is designed for single-use transport of compatible liquids that are classified as non-dangerous goods i.e. goods not classified or regulated as dangerous goods in accordance with regulations e.g. IMDG Code.

Flexitanks may be constructed from polyethylene, polyethylene blends and polyvinyl chloride, but other materials can also be used.

The containers used for flexitanks are ISO dry freight 20 ft general purpose freight containers (ISO code 22G1). The flexitank should be a maximum of 24000kg and usually 24000 litres. Flexitanks can also be specially designed for 40ft containers and refrigerated containers.

In addition to the transport of flexitanks in accordance with the COA Code of Practice, transport is subject to the provisions of the IMO/ILO/UNECE Code of Practice for Packing of Cargo Transport Units (CTU Code) and other statutory and industry requirements that might apply.

The global use of flexitank systems has grown substantially in recent years. It is estimated that more than 1.3 million flexitanks are transported annually.

COA Code of Practice

The Code of Practice requires that the COA membership of flexitank manufacturers and operators conform to the COA Quality Conformance (CQC) management system and submit their manufacturing and operating processes to independent quality audits and tests.

Conformance with the Code of Practice forms part of the COA shipping line (carriers) risk assessment process when evaluating container flexitank systems for carriage by sea.

On satisfactory completion of the audits and tests, the manufacturer achieves COA Quality Conformance (CQC). Audits are repeated periodically.

Flexitank Quality List (FQL)

The COA Flexitank Quality List (FQL) provides a list of flexitank original equipment manufacturers (OEM) and operators of flexitanks that have been awarded the COA Quality Conformance (CQC). The CQC is not issued in document form. The FQL can be downloaded from the COA website.

An original equipment manufacturer (OEM) is the company that manufacturers the flexitank, constructing the flexitank from materials purchased from suppliers. The OEM designs, develops and undertakes quality assurance to its range of flexitanks. An OEM might additionally manufacturer flexitanks that have been designed or the design modified by a flexitank operator or another company. The OEM provides its manufactured flexitanks to Operators and other industrial users.

An Operator procures and manages the use of the flexitank including providing services such as supply, cargo risk assessment, transport logistics, arranging installation into the container and removal of the used flexitank and recycling. Some operators might design flexitanks to meet their own requirements (OD) and arrange manufacturer of their design by an OEM. An operator might be an associated entity of the manufacturer (OM) or an independent entity, the shipper or agent.

The FQL  is used as a reference for shipping line risk assessment and is regularly updated.

Table 1 – Holders of COA Quality Conformance CQC
Table 1 lists COA member companies that achieved the COA Quality Conformance (CQC)


Flexitank Recycling

The COA supports the sustainable use of containers and flexitanks and encourages re-cycling of materials.

Containerised transport of substances in bulk by the use of a flexitank, provides for a reduction in its carbon footprint compared with alternative smaller packages. However, as with all non-reusable packaging, the recycling of the used flexitank is a necessary part of the supply chain consideration and an industry priority.

Flexitank materials of construction are recyclable but the process requires funding. It requires participants in the transport chain and especially the end-user who is the responsible contractual instigator of the use of the flexitank, to mandate and be prepared to accept the cost of recycling as an essential part of the flexitank offering.

Nowadays, the transport chain participants including chemical and food producers and end users promote valued environmental policies and credentials. The recycling of flexitanks is consistent with industry and COA objectives.

Flexitank manufacturers and operators who are members of the COA commit to achieving an eco-friendly life cycle. This is demonstrated by the COA Code of Practice which provides for members to achieve ISO 14001 Environmental Management Systems as part of the COA Quality Compliance procedure. Manufacturers’ instruction manuals provide for practical guidance on recycling procedures. Operators offer recycling services.

The provision of global recycling facilities is part of the infrastructure that enables flexitanks to be consolidated in economically viable bulk quantities for recycling at specialist plants. The COA directory of these facilities is being developed to assist operators and end-users to readily identify service options.

The recycling consolidation facilities drain the flexitank, break into its component parts, shred the materials, wash and prepare for the material for recycling at a plastics plant. Flexitanks that have transported substances that cannot be readily drained sufficiently to be suitable for shredding and consolidated with other flexitanks, require prior cleaning.

Once the used flexitank is processed into a manageable state the specialist recycling plant is able to convert the waste into a useable form.

Metal parts used for restraining the flexitank (bulkheads) can be serviced and re-used or recycled as scrap metal. Cardboard used for lining the containers before installing the flexitank are readily recycled.

To facilitate re-cycling of flexitanks, the COA maintains a Recycling Facility Directory.

Members are encouraged to contribute to the directory by providing addition information.

Upcoming Flexitank Events



Previous Flexitank Events


12th COA Flexitank Meeting – Amsterdam

12th COA Flexitank Meeting – Amsterdam

Event location - Hyatt Place Hotel, Amsterdam

Event date - 20160629

June 2015: 11th COA Flexitank Meeting

Event location - Hamburg

Event date - 20150616

Event date end - 20150616

May 2013: 9th COA Flexitank Meeting

Event location - London

Event date - 20130523

Event date end - 20130523

COA 2019 Flexitank meeting

COA 2019 Flexitank meeting

Event location - Qingdao, China

Event date - 20190524

Event date end - 20190524