"Many herbal vaporizer manufacturers tend to use plastic parts for there vaporization tools. Plastic over time will emit lethal toxins in which we inhale. Plastic is not recommended in vaporization systems unless it is away from the heated stream of air. Many marijuana vaporizers including Vapir and Volcano both use plastic parts directly in the inhalation chamber. Weed Vaporizer manufacturers use plastic due to the cost when compared to borosilicate glass. A few glass vaporizer manufacturers use borosilicate glass which is more significant in cost, but allows a more health conscience design. Stay away from cheap vaporizer manufacturers with plastic chassis, over time they will warp and become less efficient while releasing toxins for you to inhale."