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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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Potassic extracts are a multiconstituent substance composed of simple inorganic salts (i.e. potassium sulfate, sodium sulfate and calcium sulfate). In aqueous environment, the soluble portion of each constituent completely dissociates into the sulfate ion (SO42 -) and the corresponding cations : potassium (K+), sodium (Na+) and calcium (Ca2 +) at neutral pH. Sulfate is a normal constituent of the blood and is a normal metabolite of sulfur-containing amino acids. Sulfate does not accumulate in tissues and is usually eliminated by renal excretion. It has also an important role in the detoxification of various endogenous and exogenous compounds, as it may combine with these to form soluble sulfate esters that are excreted in the urine. In humans, absorption of small amounts of sulfate from the gut occurs rapidly and almost completely. In a study with 8 volunteers, small amounts (60 -80 µCi) of radioactive sulfate-35 were administered orally or intravenously. Plasma equilibrium was reached within 60 to 105 and 60 to 90 minutes respectively, and in both cases 80 % or more of the administered amount of radioactivity was recovered in the urine within 24 hours (Bauer et al., 1976). After absorption free sulfate ions rapidly distribute over the extracellular space, the apparent volume of distribution being around 20 % of the body volume. The serum concentration of sulfate in humans ranges between 1.4 and 4.8 mg/100 ml, with a mean of about 3.1 mg/100 ml. Excretion is mainly in urine. The renal clearance is approximately one third of the glomerular filtration rate, indication tubular re-absorption. However, the total free sulfate excretion rate is not dependent on urine flow rate. Organically bound sulfate may follow different excretion patterns (Cochetto and Levi, 1981).

Conclusion: Sulfate (and sodium, calcium, potassium) ions are important constituents of the mammalian body and of natural foodstuffs and there is a considerably daily turnover of these ions. Near-complete absorption of diatery sulfates may occur at low concentration, depending on the counter-ion, but absorption capacity can be saturated at higher artificial dosages. At diatery levels, excretion is mainly in the urine. Sulfates are found in all body cells, with highest concentrations in connective tissues, bone and cartilage. Sulfates play a role in several important metabolic pathways, including those involved in detoxification processes. Based on low MW, high water solubility, assumed low logPow high absorption is expected. However, the ion formation of the substance immediately after contact wirh a fluid decreases the absorption. Taken into consideration the guidance, 50 % absorption for oral, dermal and inhalation exposure has been retained.