The Chemical Weapons Convention


The Chemical Weapons Convention (CWC) is an international arms control treaty, administered by the Organisation for the Prohibition of Chemical Weapons (OPCW) based in The Hague, Netherlands, which aims to prohibit the development, production, stockpiling or use of chemical weapons.

One of the ways the CWC aims to achieve this is by monitoring the peaceful and legitimate use of industrial chemicals in order to prevent the possibility of their diversion into weapons. 

The CWC’s provisions extend to all activities involving a large number of toxic and non-toxic chemicals. Ireland is a party to the CWC.

The Chemical Weapons Act, 1997 transposed the provisions of the CWC into Irish law, covering not only acts done in Ireland but also acts performed elsewhere by Irish Nationals and companies.

Storage of quantities of materials specified in the 3 schedules to the Act imposes duties, including licensing, annual declarations, and potential for inspection by the OPCW.

National Authority

Each State is obliged to designate or establish a National Authority. In Ireland this is the Health and Safety Authority. The National Authority escorts OPCW inspections of relevant industrial sites and submits initial and annual declarations. The National Authority acts as the focal point with regard to interaction with the Technical Secretariat of the OPCW.


It is a requirement in the Chemical Weapons Convention that on an annual basis, declarations are submitted to the OPCW by specified timelines. To facilitate  the preparation of these Declarations chemical information is submitted by the chemical industry to the National Authority. A summary of the activities which are declarable is given in Section B; page 2 of the OPCW Declarations Handbook.

It is important that the information submitted by industry to the National Authority is accurate, as it is these declarations that decide whether a site is inspectable by the OPCW or not. Only sites above the declaration thresholds will be inspected by the OPCW. Some of the common errors with regard to declarations are summarised in Section B; Page 28 of the OPCW Declarations Handbook.

The OPCW have created a database of scheduled chemicals which will assist Industry with regard to identifying declarable scheduled chemicals. A link to the OPCW Chemicals Database can be accessed here.


Notification of an inspection

Companies will be notified by the National Authority (i.e. HSA) that they have been selected for inspection by the OPCW between one to five days (or perhaps more) in advance. The length of notice will vary, depending on whether the inspection relates to a declaration of a Schedule 2, Schedule 3 or a DOC/PSF* site, and on the timing of notifications by the OPCW.

*DOC/PSF refers to sites producing by synthesis more than 200 tonnes of unscheduled discrete organic chemicals (DOC) or more than 30 tonnes of unscheduled discrete organic chemicals containing phosphorus, sulphur or fluorine (PSF) in any year.

Duration of Inspections

The inspection of a Schedule 2 site may last up to 96 hours, and inspections of Schedule 3 or DOC sites up to 24 hours. Once an inspection starts, activities can continue around the clock, although Inspectors tend not to work this way for routine inspections. The inspection period may be extended by agreement.

Frequency of Inspections

The frequency of routine inspections is determined by the OPCW, taking into account the perceived risk that the particular site presents to the purpose and objective of the CWC - subject to such sites receiving not more than 2 routine inspections per year.

The Inspectors

The Inspectors are full-time, qualified and trained members of the Technical Secretariat of the OPCW. They are nationals of countries that have ratified the CWC and each inspector will have been accepted by the Irish Government, to undertake inspections in Ireland.  The size of an Inspection Team will be determined by the Technical Secretariat, based upon its assessment of the requirements of a particular inspection. A team will usually comprise about 3 Inspectors.

Inspector activities during the Inspection

During the inspection, the Inspectors will observe all the site’s rules and regulations on health and safety. They will have rights of access to areas of the site sufficient to enable them to undertake their duties. The Team will be entitled to interview site staff as necessary about their duties. They will also have the right to inspect relevant documents and records, and to have photographs and samples taken for analysis, as necessary. Unless agreed by the company, the Inspectors will not operate any of the site’s equipment, but they can require particular operations to be performed by the site’s staff. The Inspectors will require to visit the manufacturing and storage locations, including waste treatment facilities. Explanations of stock control systems, batch yield variations and failures may be required. The Inspectors follow a ‘no-touch’ policy during the inspection

Safeguarding of confidential information

The CWC, and internal OPCW policy, provide that the Inspectors should seek only information that is strictly necessary for the conduct of the inspection, and that access within the OPCW to commercially sensitive information will be allowed solely on a need-to-know basis.

The Chemical Weapons Act, 1997 makes the unauthorised disclosure of information obtained under the Act - with exceptions in certain clearly defined circumstances - a criminal offence. Companies have the right to take measures to protect commercially confidential information and data not relevant to the purposes of the CWC. They may do so by means of Managed Access.

National Authority Assistance

If necessary, after an inspection has been notified by the OPCW, the National Authority will send a representative to the site to take management and others through the processes involved.

The National Authority will seek clarification on the company’s behalf on any matter, at any time, during the inspection. It will also help to address any problem that may arise in the course of efforts to protect commercial confidentiality and the implementation of Managed Access Procedures.

Further Information

For further information about any aspect of the Chemical Weapons Convention, please contact: the Health and Safety Authority (CCPS Unit), 1A South Mall, Cork or – (put ‘Chemical Weapons’ in the message header).

The OPCW site ( contains detailed information on the Convention.