Sodium+tetraborate

Sodium tetraborate is also known as Borax, sodium borate, or disodium tetraborate. It is an important boron compound, a mineral, and a salt of boric acid. It is usually a white powder consisting of soft colorless crystals that dissolve easily in water.

It was discovered over 4000 years ago. Borax is usually found deep within the ground, although it has been mined near the surface in Death Valley, California since the 1800s. Although it has numerous industrial uses, in the home borax is used as a natural laundry booster, multipurpose cleaner, fungicide, preservative, insecticide, herbicide, disinfectant, dessicant, and ingredient in making 'slime'. Borax crystals are odorless, whitish (can have various color impurities), and alkaline. Borax is not flammable and is not reactive. It can be mixed with most other  cleaning agents, including chlorine bleach.

Borax has many chemical properties that contribute to its cleaning power. Borax and other borates clean and bleach by converting some water molecules to hydrogen peroxide (H2O2). This reaction is more favorable in hotter water. The pH of borax is about 9.5, so it produces a basic solution in water, thereby increasing the effectiveness of bleach and other cleaners. In other chemical reactions, borax acts as a buffer, maintaining a stable pH needed to maintain cleansing chemical reactions. The boron, salt, and/or oxygen of boron inhibit the metabolic processes of many organisms. This characteristic allows borax to disinfect and kill unwanted pests. Borates bonds with other particles to keep ingredients dispersed evenly in a mixture, which maximizes the surface area of active particles to enhance cleaning power.

Borax is natural, but that does not mean it is automatically safer for you or for 'the environment' than man-made chemicals. Although plants need boron, too much of it will kill the m, so borax can be used as an herbicide. Borax may also be used to kill roaches, ants, and fleas. In fact, it is also toxic to people. Signs of chronic toxic exposure include red and peeling skin, seizures, and kidney failure. The estimated lethal dose (ingested) for adults is 15-20 grams; less than 5 grams can kill a child or pet. For this reason, borax should not be used around food. More commonly, borax is associated with skin, eye, or respiratory irritation. It is also important to point out that exposure to borax may impair fertility or cause damage to an unborn child. Now, none of these risks mean that you shouldn't use borax. If you do a bit of research, you will find risks associated with all cleaning products, natural or man-made. However, you do need to be aware of product risks so that you can use those products properly. Don't use borax around food, keep it out of reach of children and pets, and make sure you rinse borax out of clothes and off of surfaces before use. 

Where it Comes From

 * occurs naturally in evaporite deposits prodeced by repeated evaporation
 * The important deposits are found in Turkey and California
 * It can also be produced synthetically from other boron compunds
 * Once it is found, it is refined by a process of re-crystallization

Toxicity
Borax, sodium tetraborate decahydrate, is not acutely toxic. Its LD50 (median lethal dose) score is tested at 2.66 g/kg in rats a significant dose of the chemical is needed to cause severe symptoms or death. The lethal dose is not necessarily the same for humans. Sufficient exposure to borax dust can cause respiratory and skin irritation. Ingestion may cause gastrointestinal distress including nausea, persistent vomiting, abdominal pain, and diarrhea. Effects on the vascular system and brain include headaches and lethargy, but are less frequent. "In severe poisonings, a beefy red skin rash affecting palms, soles, buttocks and scrotum has been described. With severe poisoning, erythematous and exfoliative rash, unconsciousness, respiratory depression, and renal failu re. A reassessment of boric acid/borax by the United States Environmental Protection Agency Office of Pesticide Programs found potential developmental toxicity (especially effects on the testes). Boric acid solutions used as an eye wash or on abraded skin are known to be particularly toxic to infants, especially after repeated use, because of the slow elimination rate. Borax was added to the Substance of Very High Concern (SVHC) candidate list on 16 December 2010. The SVHC candidlate list is part of the EU Regulations on the Registration, Evaluation, Authorisation and Restriction of Chemicals 2006 (REACH), and the addition was based on the revised classification of Borax as toxic for reproduction category 1B under the CLP Regulations. Substances and mixtures imported into the EU which contain Borax are now required to be labelled with the warnings "May damage fertility" and "May damage the unborn child".