The team of 14 U.N. staff members and 19 Organization for the Prohibition of Chemical Weapons inspectors has begun "securing the sites where the team will operate, especially in outlying areas," Martin Nesirky, a spokesman for Secretary-General Ban Ki-moon, told reporters at U.N. headquarters in New York.
"The team has also been considering the health and environmental hazards which they may have to confront," he said.
Before they start the actual process of disabling Syria's chemical weapons production facilities, the inspectors will also fill gaps in Syria's initial disclosure of its inventory of poison gases, nerve agents, delivery systems and production sites, U.N. and OPCW officials said.
The OPCW has not said how many locations are expected to be involved -- a Syrian declaration of its sites is confidential -- but outside experts say there are as many as 70 sites.
The first phase in disabling of Syria's chemical weapons production facilities "should begin soon," Nesirky said.
The U.N. Security Council directed OPCW Friday to help Syria destroy its chemical-weapons program in the next nine months.
The OPCW is not part of the United Nations but cooperates with it.
Under the U.N. resolution, all chemical production and mixing plants, along with equipment used for filling rockets and shells with nerve agents or sulfur mustard gas, must be destroyed by Nov. 1, to crush the heart of the chemical-weapons program as soon as possible.
Syrian President Bashar Assad has promised to comply with the resolution.
The OPCW-U.N. team stressed in a statement Wednesday "the onus was on the Syrian government to meet the verification and destruction deadlines."
A spokesman for the opposition Syrian National Coalition told the BBC the rebel Free Syrian Army would ensure inspectors were "protected and granted access to all locations."
But the army is only one of several rebel factions operating in Syria, and 13 of Syria's most powerful rebel groups said last week they no longer recognized the coalition.
Syrian Foreign Minister Walid al-Muallem has said seven of the 19 chemical weapons sites declared by the Assad regime last month are in combat zones and a third of the sites are outside the regime's control.
Many Syrian residents told The New York Times they thought dismantling the chemical weapons was beside the point in a war that has killed more 100,000 people, mostly with conventional arms.
"Twenty weapons inspectors will prevent the Americans from striking. They cannot strike while they are here. The regime is happy," a Damascus resident said.
"The government is very wise," a regime supporter in the western coastal province of Latakia told the newspaper. "They gave up these weapons, which we do not need anyway, for the sake of peace for the Syrian people."