Gas prices in Massachusetts ticked up 2 cents last week as refineries slow production and prepare for maintenance.

The average cost of a gallon in the Bay State hit $3.18, according to the latest survey. That’s 6 cents higher than a week ago and 17 cents cheaper than a year ago.

“Gas prices are likely to increase as more refineries undergo seasonal maintenance, especially with ongoing tensions in the Middle East putting upward pressure on oil prices,” said Mark Schieldrop, Senior Spokesperson for AAA Northeast.

The Seattle-based parent company behind the viral Stanley tumbler faces more lawsuits accusing it of intentionally misleading consumers about the presence of lead in its products.

Two separate lawsuits filed last week accuse Stanley, which was acquired by Seattle-based PMI Worldwide in 2002, of deceiving customers and failing to disclose the presence of lead in its products, most notably its viral Quencher tumblers.

In January, the company informed its millions of consumers who bought a Quencher tumbler in the past several years that the product contains lead.

Stanley’s vacuum insulation process uses “an industry standard pellet to seal the vacuum insulation at the base of our products,” according to a statement on its website. The sealing material, it said, “includes some lead.”

Once sealed, the area containing lead is covered with stainless steel, making it inaccessible to consumers. Lead is not present “on the surface of any Stanley product that comes into contact with the consumer nor the contents of the product,” the statement added. PMI did not respond to a request for comment.