Sulfate (SMCL: 250 milligrams per liter)

Sulfate has no known health effects at concentrations up to about twice the standard, so it has a secondary standard. High concentrations of sulfate in drinking water have three effects:

• Water containing appreciable amounts of sulfate tends to form hard scales in boilers and heat exchangers
• Sulfate affects taste
• High sulfate can cause laxative effects for those not used to it

The laxative effect of sulfates is usually noted in transient users of a water supply because people who are accustomed to high sulfate levels in drinking water have no adverse response. Diarrhea can be induced at sulfate levels greater than 500 milligrams per liter but more typically near 750 milligrams per liter.

While sulfate imparts a slightly milder taste to drinking water than chloride, the taste threshold may be as low as 300 milligrams per liter.

Sulfide is another form of sulfur That has the rotten egg smell. It has enough odor that your won't drink enough of it to cause harm, do to the odor. The issues with it are the same laxative properties as sulfate.

If it is not dissolved in water, then you are asking about some of the mineral forms of sulfur. In the mineral form, it really depends on the metallic ion it is combined with. Epsom salts are magnesium sulfate. It has some benefits and has long been used for health reasons. If it is combined with a heavy metal, then you have the issues and toxic effects of the heavy metal, like lead sulfate.

Elemental sulfur is relatively harmless, but is very toxic to many bacteria and fungi. Sulfur dust irritates eyes and eyelids. Carbon disulfide, hydrogen sulfide, and sulfur dioxide in high concentrations should be handled extremely carefully. And of course, sulfuric acid is one of the stronger acids.