Marijuana dispensaries in California are pulling products off their shelves after a recent investigation found a majority of the medical products tested from stores contained dangerous contaminants.

Officials from California’s Bureau of Medical Cannabis Regulation promised Thursday to revamp safety regulations governing medical marijuana testing to address the issues. The investigation by NBC4 I-Team in Los Angeles found some marijuana products in the state are covered with pesticides, despite assurances from shop workers the items are clean, reports NBC Los Angeles.

The investigators said they bought 44 different marijuana products from various dispensaries in Southern California, specifically asking if they were free of contaminants. Then they sent the marijuana to Steep Hill Laboratories in Berkeley for testing, and found roughly 93 percent of the products contained high levels of pesticides exceeding many safety limits in other states with legal marijuana.

“I think the goal of California is to make sure the public and patients have safe cannabis and so I think it is important that we test the product and that we’re testing for pesticides,” Lori Ajax, director of California’s Bureau of Medical Cannabis Regulation, told NBC Los Angeles. “All cannabis will need to be tested before it is passed on to the dispensary to be sold at retail.”

While patients may assume medical marijuana in California is already stringently tested, there are no current requirements for lab testing of products. Officials with the state’s Bureau of Medical Cannabis Regulation will establish concrete rules for testing and regulating marijuana by next year, when the state implements recreational marijuana legalization.

Massachusetts completely bans the use of chemicals in the production of medical marijuana, while states like Colorado and Oregon put strict limits on pesticide levels.

Earlier this year California’s medical marijuana program came under similar scrutiny after a man died from a fungus linked to his marijuana. After the man’s death doctors from the University of California, Davis partnered with Steep Hill Labs to test medical marijuana samples from dispensaries across the state for contaminants.

Officials said roughly 90 percent of the marijuana they tested had positive traces of some form of fungus or bacteria. While a healthy adult is not likely to be affected by these kinds of pathogens, it presents problems for medical patients with diminished immune systems.

“For the vast majority of cannabis users, this is not of great concern,” Dr. George Thompson, professor in the UC Davis Department of Medical Microbiology and Immunology, told The Sacramento Bee in February.

Medical marijuana is legal in 28 states and is legal in Washington, D.C., for recreational use. Voters in Maine, Nevada, California and Massachusetts all approved measures to legalize marijuana for recreational use on Election Day 2016.

Nearly 1 in 5 Americans now have access to legal pot.

Follow Steve on Twitter

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.