The slow move toward a statewide ban of plastic-bag usage by businesses finally took effect Oct. 1.

The state Department of Ecology said in a news release that all Washington businesses that have provided single-use plastic bags to customers at checkout stations must comply with the new law. The state agency said food service businesses, restaurants, retail, small and temporary vendors, and grocery stores will be forbidden from providing single-use plastic carryout bags to customers.

Customers are encouraged to bring their own reusable bags, but they may purchase a compliant paper or reusable bag from the merchant.

Laurie Davies, Ecology’s solid waste management program manager, said, “If a merchant doesn’t want its employees handling customers’ reusable bags, it can implement a policy requiring them to bag their own purchases when customers bring their own.”

Plastic bags are a source of environmental pollution and are a major contaminant in Washington’s recycling system that clog sorting machines and put worker safety at risk, Davies says in the news release.

The law requires merchants to charge at least 8 cents per bag to help recover costs of the more durable — and reusable — compliant bags, and as incentive for customers to bring their own bags. The agency said the charge is not a tax; it is kept by the merchant.

Food banks and pantries are not required to charge customers for compliant bags, according to Ecology. Also, individuals receiving food stamps and other government food assistance programs are not subject to the 8-cent charge.

Some types of single-use plastic bags are exempt from the law, including film plastics used to wrap meats and produce, small film bags for prescriptions, newspapers and dry-cleaning bags, and packaged bags sold in stores. Customers can dispose of them in the garbage or at recycling dropoff location.