Hemp shampoo will not cause a false positive on a hair test for 2 reasons.
1. The hair test looks for metabolites of THC, not actual THC.
2. THC levels in hemp seed oil are in the low parts per million or even lower. Hemp seed oil is only a minor ingredient in the shampoo so it is far more diluted than straight oil. THC levels (if any) in a hemp shampoo would be immeasurable.
Cannabis is the most durable of the hemp plants, and it produces the toughest cloth, called `canvass.' (Canvass was widely used as sails in the early shipping industry, as it was the only cloth which would not rot on contact with sea spray.) The cannabis plant also produces three other very important products which the other hemp plants do not (in usable form, that is): seed, pulp, and medicine.
The pulp is used as fuel, and to make paper. The seed is suitable for both human and animal foods. The oil from the seed can be used in as a base for paints and varnishes. The medicine is a tincture or admixture of the sticky resin in the blossoms and leaves of the hemp plant, and is used for a variety of purposes.
Hemp requires little fertilizer, and grows well almost everywhere. It also resists pests, so it uses little pesticides. Hemp puts down deep roots, which is good for the soil, and when the leaves drop off the hemp plant, minerals and nitrogen are returned to the soil. Hemp has been grown on the same soil for twenty years in a row without any noticeable depletion of the soil.
Using less fertilizer and agricultural chemicals is good for two reasons. First, it costs less and requires less effort. Second, many agricultural chemicals are dangerous and contaminate the environment -- the less we have to use, the better.
The cloth that hemp makes may be a little less soft than cotton, (though there are also special kinds of hemp, or ways to grow or treat hemp, that can produce a soft cloth) but it is much stronger and longer lasting. (It does not stretch out.) Environmentally, hemp is a better crop to grow than cotton, especially the way cotton is grown nowadays. In the United States, the cotton crop uses half of the total pesticides. (Yes, you heard right, one half of the pesticides used in the entire U.S. are used on cotton.) Cotton is a soil damaging crop and needs a lot of fertilizer.
Both the fiber (bast) and pulp (hurd) of the hemp plant can be used to make paper. Fiber paper was the first kind of paper, and the first batch was made out of hemp in ancient China. Fiber paper is thin, tough, brittle, and a bit rough. Pulp paper is not as strong as fiber paper, but it is easier to make, softer, thicker, and preferable for most everyday purposes. The paper we use most today is a `chemical pulp' paper made from trees. Hemp pulp paper can be made without chemicals from the hemp hurd. Most hemp paper made today uses the entire hemp stalk, bast and hurd. High-strength fiber paper can be made from the hemp baste, also without chemicals.
The problem with today's paper is that so many chemicals are used to make it. High strength acids are needed to make quality (smooth, strong, and white) paper out of trees. These acids produce chemicals which are very dangerous to the environment. Paper companies do their best to clean these chemicals up (we hope.) Hemp offers us an opportunity to make affordable and environmentally safe paper for all of our needs, since it does not need much chemical treatment. It is up to consumers, though, to make the right choice -- these dangerous chemicals can also be used on hemp to make a slightly more attractive product. Instead of buying the whiter, brighter role of toilet paper, we will need to think about what we are doing to the planet.
Because of the chemicals in today's paper, it will turn yellow and fall apart as acids eat away at the pulp. This takes several decades, but because of this publishers, libraries and archives have to order specially processed acid free paper, which is much more expensive, in order to keep records. Paper made naturally from hemp is acid free and will last for centuries.