Hundreds of members of Teamsters Local 431 have been on strike since Monday, shutting down the Kingsburg raisin factory in Fresno County for two days before it re-opened Wednesday with non-union workers.

In early August, management at Sun-Maid Raisins and local union leaders reached a tentative agreement that included a 50-cent hourly wage increase for workers. But it was ultimately voted down by union members.

The dispute is over health care. Previous contracts between the two parties included 100 percent employer-paid health coverage for workers. But the new contract proposed in August would’ve required employees to pay some portion of their health insurance costs.

According to a statement from the company, negotiations came to an impasse so Sun-Maid went ahead and implemented the terms of the tentative agreement on August 20.