What is the purpose of a zipper clause in a collective bargaining agreement?
The purpose of a zipper clause in a collective bargaining agreement is to prevent either side from bringing up issues and asking to bargain them once the contract has been signed. This protects both sides from being constantly bombarded with demands to bargain over various topics.
A zipper clause closes the collective bargaining agreement (CBA), making sure that it cannot be unilaterally reopened. Such a clause is needed because federal law says that parties to a CBA must be willing to bargain on any issue that is not included in the CBA at any time during that contract’s life. The zipper clause essentially waives this right. It says that no issue that is not already contained in the CBA may be bargained during the life of the contract.
For example, then, imagine if a CBA had not contained any language about the drug testing of employees. Then imagine that after the contract is signed, the employer wants to raise the issue of testing and wants to force the union to bargain on that issue. With a zipper clause, the employer cannot do this because the zipper clause specifically states that neither side can demand to bargain any issue during the life of the CBA.