Not always! While many do have butane and intane contamination, many more are co2 extracted and do not contain those chemicals. The dispensery I work for uses ONLY organically farmed cannabis and organic extractions. We use only cold water and co2 extractions for our products and no pesticides on our plants and flowers. Just do some research on dispensaries in your area and dont be afraid to ask questions. If one objects to being asked questions, you probably don’t want to get medicine from them. Good luck!
Unfortunately many concentrates are made from flowers grown indoors with the use of pesticides (generally to combat the nearly unavoidable infestation of broad mites and russet mites). Often indoor growers also use chemical fertilizers. If these chemicals are present, then extraction methods used to create concentrates, does indeed concentrate the chemical components. It’s incredibly important to know the source of your flowers and search out dispensaries and vendors that carry only pure, tested and if possible, outdoor grown source material.