Registration Dossier

Administrative data

Link to relevant study record(s)

Description of key information

Quantitative data on the toxicokinetics of elemental sulfur via the oral, dermal and inhalation route (in humans and animals) are not available.

However, qualitative data on the oral route of administration indicate that elemental sulfur is probably converted first to hydrogen sulfide, by colonic bacteria, and subsequently absorbed (in humans and non-ruminant animals). Other sulfur-containing ions may be formed as well.

In ruminant animals, sulfur is rapidly reduced in the rumen to sulfite and hydrogen sulfide, with some of the hydrogen sulfide being oxidised to sulfate. Some of the hydrogen sulfide is incorporated into microbial protein before being absorbed in the form of essential amino-acids methionine and cysteine.

Sulfur penetrates the skin and is detectable in the epidermis within two hours and throughout skin within eight hours after application. However, 24 hours after application there are no detectable levels of sulfur remaining in the skin.

Key value for chemical safety assessment

Bioaccumulation potential:
low bioaccumulation potential

Additional information

No quantitative data are available on the toxicokinetics of elemental sulfur via the oral, dermal and inhalation route, neither in animals nor in humans. According to the American Hospital Formulary Service (2003), sulfur penetrates the skin and is detectable in the epidermis within two hours and throughout skin within eight hours after application. However, 24 hours after application there are no detectable levels of sulfur remaining in the skin. Regarding the oral route, sulfur is probably converted first to hydrogen sulfide, by colonic bacteria, and subsequently absorbed (in humans and non-ruminant animals).

Sulfur is an essential element in the metabolism of all living organisms. The average human body contains about 175 g of sulfur incorporated into sulfate, proteins, keratin and enzymes.

Elemental sulfur has been commonly used as a nutritional supplement in ruminant animals.

Data on the oral route of administration indicate that elemental sulfur is transformed into soluble forms of sulfur, first into hydrogen sulfide, probably by the intestinal microflora, and then into sulfate. This seems to be equally valid for animals (both ruminant and non-ruminant) and humans. Other sulfur-containing ions may be formed as well. These sulfur compounds may be absorbed from the gut and incorporated into endogenous sulfur-containing molecules.