A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Toxipedia: H

HDPE

Also referred to as PE. It comes in the form of high density PE (HDPE) or low density PE (LDPE). Examples of HDPE are milk and detergent bottles. LDPE may be found in the form of bags, film or wrapping.

Hemp

Hemp (or cannabis) is the name of the soft, durable fiber that is cultivated from plants of the Cannabis genus, cultivated only for industrial (non-drug) use in many countries around the world including Canada, France, and China. It is an incredible natural resource, with three main uses for the plants:

Hemp Fiber - For centuries the fiber has been used for paper, rope and cloth. Hemp fiber is extremely durable and makes great clothing (Levis jeans were originally made with hemp!). Today, industrial hemp is also used for biodegradable plastics and construction materials.

Hemp Seeds - High in protein and very healthy for humans, increasingly found in health food products.

Hemp Oil - Used as lamp fuel, in cooking, as an ingredient in soap, and can be made into biodiesel or hemp ethanol.

Hemp is a renewable resource with a short growth cycle of 100-120 days, and it is an efficient and economical crop for farmers to grow as it requires few pesticides and no herbicides. However, industrial hemp cannot be commercially grown in the United States because it is erroneously confused with marijuana -- leaving U.S. farmers behind in this multi-billion dollar industry while countries like Canada have successfully introduced hemp farming.

The variety of Cannabis grown for industrial use in Europe, Canada, and elsewhere is different from the variety primarily used for production of recreational and medicinal drugs which has poor fiber quality. Strains of Cannabis approved for industrial hemp production produce only minute amounts of this psychoactive drug, not enough for any physical or psychological effects. Typically, hemp contains below 0.3% THC, while Cannabis grown for marijuana can contain anywhere from 6 or 7 % to 20% or even more.

While more hemp is exported to the United States than to any other country, the U.S. Government does not consistently distinguish between marijuana and the non-psychoactive Cannabis used for industrial and commercial purposes.

HEPA

HEPA (High Efficiency Particulate Arresting) air filters retain particles to 0.3 microns and are 99.97% efficient. Filtered particles include pollen, mold spores, bacteria, smoke particulates, animal hair and dander, dust, and dust mites.

herbicide

honeydew

hydrochloric acid

See Chlorine.

hypoallergenic

This term is used to describe items (especially cosmetics and textiles) that cause or are claimed to cause fewer allergic reactions.