the declaration and to the rules in the convention, Schedule 1 chemicals are produced. At Schedule 3 and DOC, the main aim is to check the declaration and to verify the absence of Schedule 2 and Schedule 1 production units. The time limit Schedule 2 inspections is 96 hours while Schedule 3 and DOC inspections can take a maximum of 24 hours. There is no time limit on Schedule 1 inspections. Challenge inspections and investigations of alleged use In case of allegation of use of chemical weapons or the prohibited production, a fact-finding inspection can be employed according to the convention. None of those activities have taken place, although the OPCW contributed to investigations of alleged use of chemical weapons in Syria as part of a United Nations mission. The OPCW only undertakes these inspections on request of another member state, after verification of the presented proof. To avoid misuse, a majority of three-quarters can block a challenge inspection request. Relations with the United Nations While the OPCW is not a specialised agency of the United Nations, it cooperates both on policy and practical issues as a related organisation. On 7 September 2000, the OPCW and the United Nations signed a cooperation agreement outlining how they were to coordinate their activities. The inspectors furthermore travel on the United Nations Laissez-Passer in which a sticker is placed explaining their position, and privileges and immunities. The United Nations Regional Groups also operate at the OPCW to govern the rotations on the Executive Council and provide informal discussion platform. Membership All 193 parties to the Chemical Weapons Convention are automatically members of the OPCW. Other states which are eligible to become members are UN member states: Israel is a signatory state that has not ratified the Convention; and Egypt, North Korea and South Sudan, which have neither signed nor acceded to the Convention. Palestine was the most recent state to submit its instrument of accession to the Convention. On 21 April 2021, Syria was stripped of its voting rights at the OPCW after Syrian forces were found to have repeatedly used poison gas during the Syrian civil war. A two-thirds majority of members voted to immediately revoke Syria's privileges at the agency. Leadership The Organisation is currently led by Director-General Ambassador Fernando Arias of Spain. The Director-General is directly appointed by the Conference for a maximum of two four-year terms. A historical list