If you’re dabbing or hitting a weed vape, there’s a good chance you’re smoking pesticides. That’s according to leading California cannabis testing laboratory SC Labs. The company’s co-founder Alec Dixon recently said in an LA Weekly article that a majority of the marijuana concentrates his lab sees contain pesticides.

“When we start talking about these extracts, anything that was there in tiny amounts substantially concentrates and becomes present,” Dixon said. “In certain types of extracts, we see anywhere from 25 to 30 percent detection rate, but if you’re talking about higher-tech extract with CO2, butane and distillation, we see 50 to 75 percent.”

Marijuana cultivators in California regularly spray their crops with several pesticides, some of which aren’t approved for use on food crops. “This is really nasty stuff,” Adam Lustig, CEO and founder of Higher Vision Cannabis, told LA Weekly. “The amount of damage to someone’s health you can do with pesticides is huge.”

The extraction process itself can make pesticides more potent as well. According to Dixon, in a concentrate you’ll see a cannabinoid like THC increase by about five to seven times from the original cannabis plant, but pesticides can increase by much higher rates, up to 100 times their level in the raw plant.

The presence of pesticide in itself doesn’t necessarily make an extract toxic, but the lack of consistency in regulations may be cause for concern. The state of California has no limit on pesticide composition in extracts. The city of Berkeley has the most stringent regulations on the issue, limiting pesticide to no more than 100 parts per billion, stricter than state guidelines that exist in Colorado or Washington.

You can likely expect there to be a statewide California limit on the books by the time the recreational cannabis market opens full swing in 2018.

“In a regulated market, the product flows from cultivator to testing lab, and if it passes, it goes to the dispensary. That’s how the flow should go, but it doesn’t right now in California,” Reggie Gaudino of Steep Hill Labs told LA Weekly. “That’s how the flow should go, but it doesn’t right now in California.”