Elemental sulfur is considered to be of low toxicity.
Compounds such as carbon disulfide, hydrogen sulfide, and sulfur dioxide are toxic. For example, at 0.03 parts per million, we can smell hydrogen sulfide but it is regarded as safe for eight hours of exposure. At 4 ppm it may cause eye irritation. At 20 ppm exposure for more than a minute causes severe injury to eye nerves. At 700 ppm breathing stops. Death will result if there is not a quick rescue. Permanent brain damage may result.
Sulfur is a soft, pale yellow, odorless, brittle solid. It is insoluble in water, but soluble in carbon disulfide. It burns with a blue flame, oxidizing to sulfur dioxide.
Sulfur exists in several crystalline and amorphous allotropes. The most common form is yellow, orthorhombic alpha-sulfur, which contains puckered rings of S8.
Sulfur is multivalent and combines, with valence 2, 4, or 6, with almost all other elements. The best known sulfur compound is hydrogen sulfide (H2S). This is a toxic gas that smells like rotten eggs; the smell is used in stink bombs, many of which release a small amount of hydrogen sulfide.
Uses of Sulfur
1. Sulfur’s main commercial use is as a reactant in the production of sulfuric acid (H2SO4). Sulfuric acid is the industrialized world’s number one bulk chemical, required in large quantities in lead-acid batteries for automotive use.
2. Sulfur is also used in the vulcanization of natural rubber, as a fungicide, in black gunpowder, in detergents and in the manufacture of phosphate fertilizers.
3. Sulfur is a vital element for all forms of life. It is a component of two amino acids, cysteine and methionine.
Most sulfur is converted to sulfuric acid. Sulfuric acid is extremely important to many industries around the world. It is used in the manufacture of fertilizer, oil refining, processing wastewater, lead-acid batteries in cars, mineral extraction, removing rust from iron, making nylon and producing hydrochloric acid.
Sulfur can be used as a pesticide and fungicide. Many farmers that grow organic foods use sulfur as a natural pesticide and fungicide.
Magnesium sulfate, which contains sulfur, is used as a laxative, in bath salts and as a magnesium supplement for plants.
Sulfur is important for life. Therefore, it is added to fertilizers (in soluble form) so that plants have more sulfur available in the soil.
Carbon disulfide, a compound of sulfur, can be used to make cellophane and rayon (a material used in clothes).
Sulfur is used to vulcanize rubber. Vulcanization makes rubber tougher. It ensures that rubber maintains its shape. Car tires, shoe soles, hoses and ice hockey pucks are all made from vulcanized rubber.
Other compounds of sulfur (sulfites) are used to bleach paper and preserve fruit.
Sulfur is also one component of gunpowder.
The cleansing power of sulfur has been known for many centuries. At one time, ancient physicians burned sulfur in a house to cleanse it of impurities. Creams made with sulfur were used to treat infections and diseases. In fact, sulfur is still used to treat certain medical problems. Sulfur is prepared in one of three forms. Precipitated sulfur (milk of sulfur) is made by boiling sulfur with lime. Sublimed sulfur (flowers of sulfur) is pure sulfur powder. And washed sulfur is sulfur treated with ammonia water. Washed sulfur is used to kill parasites (organisms that live on other organisms) such as fleas and ticks. It is also used as a laxative, a substance that helps loosen the bowels.
Sulfur is a macronutrient for both plants and animals. A macronutrient is an element needed in relatively large amounts to insure the good health of an organism. Sulfur is used to make proteins and nucleic acids, such as DNA. It also occurs in many essential enzymes. Enzymes are chemicals that make chemical reactions occur more quickly in cells. Humans usually have no problem getting enough sulfur in their diets. Eggs and meats are especially rich in sulfur.
A person who does not get enough sulfur in his or her diet develops certain health problems. These include itchy and flaking skin and improper development of hair and nails. Under very unusual conditions, a lack of sulfur can lead to death. Such conditions would be very rare, however.
The cleansing power of sulfur has been known for many centuries.
Plants require sulfur for normal growth and development. When plants do not get enough sulfur from the soil, their young leaves start to turn yellow. Eventually, this yellowing extends to the whole plant. The plant may develop other diseases as a result.