A team of 20 inspectors of the Organisation for the Prohibition of Chemical Weapons is to arrive in Damascus on Tuesday on a mission to destroy Syria's chemical arsenal.
Here is a short explanation of their mandate and duties:
The OPCW chemical weapons experts are in Syria to supervise Damascus' destruction of a suspected stockpile of more than 1,000 tonnes of chemical weapons by mid-2014.
The mission comes after the OPCW over the weekend adopted a plan, called the "rules and regulations of Syria's chemical disarmament".
OPCW inspectors are now mandated to help Syria fulfil its obligations under the chemical weapons convention, which bans the production and stockpiling of chemical weapons and orders the destruction of existing stocks.
The first group of inspectors are to meet officials of Syrian President Bashar al-Assad late Tuesday before setting off to work.
Among the inspectors are former military chemical warfare experts, chemists and paramedics. They are all volunteers.
The inspectors are to check a list of sites provided by Damascus to the OPCW.
Testing is conducted on the spot "even if it does not reach laboratory levels" and has to be completed by the end of the month.
Priority is given to chemical weapons production sites which are to be disabled by late October or early November.
"Expedient methods" will be used to render these production facilities unusable, said an OPCW official.
These could include the use of explosives, sledgehammers, or pouring in concrete, the official said.
For the first time in the OPCW's history, a mission to destroy chemical weapons is being undertaken in a country embroiled in a civil war.
Under the chemical weapons convention, Syria is obligated to ensure the OPCW inspectors' safety.
"We are not going on a 'come what may' type of mission," a senior OPCW official said, adding the mission was subject to risk assessments by a UN ad hoc committee.