Yes and it’s not a single substance as some would think. N-butane,n-hexane and several others are found in naphtha. Idk man alot of people would be surprised nonetheless of how much residual solvents and of what kind of solvents can be left in “trace” amounts in there concentrate in their legal MEDICAL states
5000 ppm for butane and 290 ppm for hexane is acceptable in most legal states. Plus a long list of other shit including metals that can be present to a certain degree. Truth is nobody knows the long term effect of any residual solvents. Best to rosin press or use another form of solventless extraction. And use lab grade ethanol if you wanna refine it or render it for your purpose.