The Organisation for the Prohibition of Chemical Weapons (OPCW) is an independent international body set up in 1997 to implement the Chemical Weapons Convention.
The organisation is currently involved in destroying Syria's stockpiles of chemical weapons - the first time the OPCW has worked in a war zone.
The OPCW has been awarded the 2013 Nobel Peace Prize for its efforts to stop chemical warfare.
It carries out inspections of destruction procedures, as well as evaluating members' own declarations, in order to verify that the convention is being adhered to.
It is based in The Hague and has 189 member states, covering around 98% of the world's population, it says. These member nations have agreed to work together to create a world free from chemical weapons.
The OPCW employs around 500 people and in 2010 had a budget of 75m euros ($102m, £63m).
It is an autonomous organisation with a working relationship with the United Nations.
In early October, the head of the organisation, Ahmet Uzumcu, called for a ceasefire in Syria to enable it to destroy the country's stockpiles. He said the deadline for the destruction, under the terms of a UN resolution, was "very tight".
An inspections team came under sniper fire in Syria on 26 August, but there have been no reported attacks on inspectors since.
The Chemical Weapons Convention (CWC) was adopted by the Conference on Disarmament in Geneva in September 1992.
Under its terms the OPCW stringently verifies whether member nations are complying with the CWC.
The CWC aims to totally eliminate chemical weapons as a class, and part of the OPCW's mission is to prevent the re-emergence of chemical weapons in a country which has signed up.
Egypt, Angola, North Korea and South Sudan are not members of the OPCW.
Israel and Burma, also known as Mynamar have signed but not ratified the CWC so are also non-members.
Somalia joined in June 2013 and Syria is due to officially become a member shortly.
The US and Russia are committed to destroying their arsenals of chemical weapons under the terms of the CWC, but missed a 2012 deadline to complete this process.
They were criticised by the Norwegian Nobel committee in their announcement on Friday for missing the deadline.
The OPCW says Albania, India and a third country - widely believed to be South Korea - have completed the destruction of their declared chemical weapons.
In Libya and Iraq, as well as Syria, Russia and the US, the destruction is ongoing.