HOUSTON -- BP is the latest retailer to ban the sale of synthetic marijuana products such as K2 and Spice from its convenience stores and gas stations, according to media reports. On June 5, the chain sent a letter to local gas station owners requiring that they halt sales of Spice and similar products offered under different names.

"Beginning immediately, all BP-branded sites are prohibited from displaying, using, storing, offering or selling illegal drugs, or synthetic drugs produced to mimic illegal drugs, (including, but not limited to cannabinoids), or items that are intended or designed for use in ingesting, inhaling or otherwise consuming an illegal drug," wrote BP's Susan Hayden. "Prohibited items will include, but not be limited to, pipes, tubes, roach clips, instructions or descriptive materials, or containers for concealing illegal drugs or paraphernalia."

Compliance with federal laws and upholding BP's company image are both reasons for the ban, according to the letter.

Last week, CITGO Petroleum banned the sale of synthetic marijuana and, through the Michigan Petroleum Association (MPA), expressed its support for MI Senate Bill 1082, a measure to combat the sale and use of synthetic marijuana in Michigan. A federal ban on synthetic marijuana passed in the U.S. Senate on May 24 and could land on President Obama's desk by early July.