Hemp Oil in Cosmetics

Household & Personal Products Industry, Oct, 2001 by George R. Whalley

This notorious, natural material imparts real benefits to leave-on and rinse-off personal care products.

IT IS FASHIONABLE in cosmetic circles these days to include all sorts of rare, often exotic materials in skin care preparations. Such additions are usually accompanied by a variety of beneficial claims that are often based on folklore rather than rigorous scientific evaluation.

Be that as it may, consumer acceptance is always the final measuring stick of a product's success. Many additives are high quality oils obtained from nuts and seeds such as grape, blackcurrant, Brazil, hazel, calendula, macadamia, pecan and poppy, to name just a few. The list is expanded on a regular basis and one of the newest to grab the attention of the cosmetics industry is hemp. Ordinary hemp oil has been available for many years, but now high quality grades are commercially available which are suitable for use as cosmetic ingredients and other purposes. The trend captured widespread attention three years ago when The Body Shop became the first major retailer in the UK to introduce an innovative, hemp-based range of cosmetic products for dry skin.

The hemp plant originated in Central Asia and India, although there is the reported use of hemp in China as long ago as 2000 B.C. Hemp was cultivated for its fiber, seed and oil content as well as for hashish, a narcotic, the latter being obtained from the flowers and the upper leaves of certain varieties. It was widely cultivated throughout Europe during the Middle Ages because its flax-like fiber was used to make rough, but durable, clothing. Hemp was introduced into Chile in the 1500s and North America during the 1600s before finding its way to most of the temperate climates of the world.

Hemp belongs to the Cannabaceae family, which consists of erect climbing plants. One species, Cannabis sativa, an annual, can grow to a height of 1.8 meters in a single season if grown specifically for its fiber content. Fibers are obtained from the hollow stalks of the plant after washing, drying and removing the extraneous material. Such fibers are longer but less flexible than flax, but equally strong and durable, and have been widely used to manufacture twine, yarn, rope and coarse canvas fabrics.

A Versatile Plant

Like flax, hemp is a remarkably versatile plant with a wide variety of uses. Unlike flax, however, its development has been seriously impaired in the past when the U.S. and other countries criticized its cultivation on the grounds of it being a primary source of the hallucinogenic drug hashish. The plant became known as marijuana, "the killer weed from Mexico," around the time of the war between Mexico and the U.S., and its cultivation was subsequently banned in many countries--a ban that continues, to this day, in the U.S. However, hemp can be grown under strict license in other countries. Because hemp fibers, seeds and oils have little active drug content, their use is now permitted in Europe.

When hemp is grown for oil extraction, modern seed variants are available to produce short- and multi-spiked plants with compound palmitate leaves and small, greenish-yellow flowers. The seeds are quickly gathered and dried after maturation, when the oil can be extracted. Dried hemp seed is still widely used as a feed for caged birds and contains 30-33% of the oil. High quality oils are now commercially available using innovative extraction procedures. Statfold Seed Developments, Tamworth, UK, produces a wide range of seed oils in bulk for use in cosmetics and other products. The company's extraction process uses state-of-the-art expellers operating at temperatures below 50 [degrees] C. This allows the retention of vital oil constituents without the use of added chemicals. A refining stage is often then carried out. European seed sources include France, Turkey, Romania and certain Eastern European countries, where the hemp is grown under license.

Hashish is a drug preparation derived from resin secreted by the flowers and upper leaves of non-fiber producing varieties of Cannabis sativa. It contains 10-15% of the active ingredient 9-tetrahydrocannibol (THC) which induces hallucinogenic effects when consumed or smoked. It also exerts a powerful narcotic effect on the central nervous and cardiovascular systems. Illegal hasish is exported from many sources including Nepal, the Middle East and Latin America.

Analysis of Refined Hemp Oil

Refined hemp oil resembles sunflower oil. It is pale yellow, has little taste and low odor. It has a refractive index of 1.469-1.472 and normally contains no additives other than optional natural antioxidants. The THC level is very low, with a maximum content of five parts per million.

According to Stafold Seed Oils, refined hemp oil contains:

Free fatty acid                 0.1 (max.)
  (% as oleic)
Peroxide value                  5.0 (max.)
  (mg/kg of oil)
Color                       4.0 red (max.)
  (Lovibond 5.25 in cell)
Iodine value                       145-165
Moisture (%)                    0.1 (max.)