Hemp oil is a valuable oil derived primarily from the seeds of the Cannabis sativa plant. Since the early 20th century the term hemp is widely used to refer to varieties of Cannabis grown primarily for fiber and seed and not for the resin rich in cannabinoids such as THC, which is the psychoactive component of marijuana and hashish. Hemp oil has never been outlawed in the United States, in contradistinction to Hash oil, a potent drug derived primarily from the leaves and flowers of the female marijuana plant (or from hashish, resin and pollen collected from the plants).
Recently, part of the movement to attack the prohibition of marijuana and related products has centered on allowing greater use of hemp products. Historically, much of the impetus for marijuana prohibition came from William Randolph Hearst because of his virtual monopoly over the pulp wood used to produce newsprint. Hemp fiber produces a better quality newsprint at a lower cost, both financially and environmentally. The anti-marijuana laws were in fact anti-hemp laws.
If the anti-hemp provisions of marijuana prohibition were repealed, growth of hemp as a crop would rapidly expand because of its many commercial uses. Hemp has long been a valued source of high quality fiber and food. Hemp seed is used in in both animal feed and human food. The oil produced from hemp seed is very healthful for humans and is used in numerous skin-care products as well as in soaps and shampoos. These uses would doubtlessly be expanded significantly under more rational laws governing hemp as a crop.
Some of the pro-hemp activists have been advocating hemp oil as a potential automobile fuel. Current technology for the use of bio-fuels is easily adaptable to the use of hemp-oil. Currently, hemp oil is far too expensive to use as a practical fuel. If hemp were to again become a common legal crop in America, it is probable that some may be utilized as a fuel. The fact is that hemp could never be grown in sufficient quantities to make it a primary source of fuel.
Hemp oil also has several negatives as far as its potential use as a fuel. Like both linseed oil and tung oil, hemp oil is used in oil paints because it hardens when exposed to oxygen. Hemp oil would tend to harden in the fuel system of a car. The energy content of hemp oil is not particularly high, although it is sufficient to be useful as a fuel when other factors are weighed in. Hemp oil and other hemp products are sufficiently valuable to justify the end of hemp prohibition. The pro-marijuana movement is more likely to result in the end of hemp prohibition, but the cumulative effect of the two movements will certainly help end this embarrassing blight upon American law.